DESIGNING SKYSCRAPER CITIES /// A WSP | PARSONS BRINCKERHOFF PUBLICATION

WELCOME
WE ARE IN A
E
ngineering is not just about
science and technology, but
CONTENTS
04 THE RENAISSANCE OF TALL
Skyscrapers are being completed at a rate of nearly

16
350 a year. What can we expect from this new
high-rise generation?
THE SKY AND OTHER LIMITS
The many challenges of planning skyscraper cities
GLOBAL AGE experience. We have been
designing iconic, efficient tall buildings for
OF TALL AND more than 50 years, and it’s that
26 FAR WEST SIDE STORY
How a Manhattan railyard became the US’s biggest
SUPER-TALL experience that makes us unique. Around
ever real-estate development
the world, we are combining the latest
BUILDINGS. IT’S tools and technologies with an in-depth 32 AN ICON FROM EVERY ANGLE
understanding of how tall buildings behave
IMPORTANT TO to create the next generation of towers.
One World Trade Center has rewritten the rulebook on
tall building design
CONSIDER ALL OF In this magazine, we discuss many of
THE IMPLICATIONS the engineering and architecture
challenges, but also speak to architects,
planners, developers and clients for a more
complete overview of the requirements
Ahmad Rahimian
Ahmad Rahimian
42 THE RISING CONTINENT
The Asian-inspired skyscrapers transforming
Australia’s skylines
Director of Building Structures, USA
and economics of tall buildings and what 48 THE VERTICAL SOCIETY
they will mean for cities. Preparing for a future of living, working and playing
Many of these discussions took place in at great height
the WSP | Parsons Brinckerhoff host room
at the 2015 Council for Tall Buildings and 56 RETURN TO SLENDER
Urban Habitats conference in New York. Structural gymnastics meets Art Deco grace in
We would like to thank everyone who Manhattan
spoke during the event, and the many
attendees who came to join us over the 64 SECRETS OF THE MEGA-TALL
two days. We have tried to distill the best China is leading the way on 500m-plus towers –
of the content here – we hope you will find and the hidden systems that make them work
it interesting.

Kamran Moazami
Kamran Moazami
Head of Building Structures, UK

Editor: Julie Guppy, WSP | Parsons Brinckerhoff

Copy: Wordmule
Inhouse photography: Nicola Evans, WSP | Parsons Brinckerhoff
Design and production: Supreme Creative Ltd
 AS MORE AND MORE OF THE

RENAISSANCE
DESIGNING SKYSCRAPER CITIES ///

THE RENAISSANCE OF TALL ///

WORLD’S POPULATIONS MOVE “WE ARE LIVING AT THE CROSSROADS OF
TO CITIES, THOSE CITIES ARE TWO SIGNIFICANT TRENDS: URBANISATION
EXPANDING EVER SKYWARDS.
BUT THIS GENERATION OF
AND CLIMATE CHANGE. CITIES ARE
TOWERS WILL BE NOTHING RESPONDING BY REACHING FOR THE SKY.”
LIKE THE LAST. WE EXPLORE DAVID COOPER, WSP | PARSONS BRINCKERHOFF
FIVE OF THE KEY TRENDS
This high-rise boom is intimately
related to urbanisation. In 2014, more
than half of the world’s population lived in
urban areas, but by 2050, this is predicted
to rise to two-thirds, with 2.5 billion
new city dwellers – the equivalent of
constructing five cities the size of Beijing
every year until then. And with this growth
comes an increasing share of the global
economy: according to analyst McKinsey,
60% of global GDP is generated by the
top 600 cities.
“We are living at the crossroads of two
significant trends: urbanisation and climate
change,” says David Cooper, president of
buildings at WSP | Parsons Brinckerhoff.

OF TALL
“Cities are responding by reaching for the
sky, as a more sustainable forward path
than continuing horizontal expansion.”
With so many new urban dwellers
needing space to live and work, cities can
either grow outwards or upwards, and
they will inevitably have to do both. The
advantage of vertical expansion is that
it minimises the distances and travelling
times between homes, jobs and essential The current boom is not just producing
amenities, and maximises the value of taller versions of 20th-century towers, but
prime central sites. breaks with the past in several important
ways. A striking difference is where
But that’s not the whole story. Tall these new towers will be located. While
buildings also exert a powerful emotional urbanisation is a global trend, 90% of new
force that familiarity seems to do little to urban dwellers will be living in Africa and
diminish. Their sheer size in relation to the Asia and more than a third in just three
human scale and the views they afford countries: China, India and Nigeria. Since
from the top continue to inspire a sense 2000, China has built 43% of all the world’s
of awe and wonder. They are a show of
THE

new towers. On the other hand, India and

strength, demonstrating mastery of the Nigeria have barely started.
elements, wealth and power. Expanding
cities build landmarks to signal their Then there’s the kind of towers being
ambition and communicate their arrival built. Before 2000, two-thirds were
on the world stage. Established cities build purely commercial. Since the turn of the
he next golden age of millennium, just under half have been
T skyscrapers is upon us. 2015
them not to be outdone.
The symbolic role of high-rise buildings
apartments or hotels, and a further 19%
was a record-breaking year mixed-use. Iconic architecture, high-
for high-rise completions, with 338 new was demonstrated in the hours after the quality construction, pioneering structural
buildings over 150m, but this will quickly terrorist attacks on Paris in November systems and state-of-the-art mechanical
be beaten by the 342 expected in 2016. 2015. As the lights of the Eiffel Tower were and electrical services are revolutionising
The race is on to build high, with a frenzy extinguished in mourning for the dead, the concept of high-rise living. From
equalling that of northern American cities world cities lit up their own landmarks with our homes to the public services we
in the 1920s. Except that, this time, it’s on the colours of the Tricolore. The Auckland use, to where we spend our leisure time,
a global scale. Between 1924 and 1934, Sky Tower, One World Trade Center in life is shifting from a predominantly
49 buildings over 150m in height were New York, the Oriental Pearl Tower in horizontal plane to a much more vertical
completed, all in the US. Between 2006 Shanghai and Calgary Tower in Canada one. Over the following pages, we look
and 2016, there will be a total of 2296, with were among those glowing blue, white at the features that will define the next
new towers on every continent. and red. generation of high-rise buildings.

04 05
DESIGNING SKYSCRAPER CITIES ///

THE RENAISSANCE OF TALL ///

“MILLENNIALS INCREASINGLY WANT
A DENSE URBAN QUARTER WITH A REAL
MIX OF USES – AREAS THAT ARE BUZZING
AND ACTIVE AT ALL TIMES”
ANDREW CANTOR, RELATED

A city’s skyline is its signature. But it’s This blurring won’t just be a lifestyle
what happens at street level that defines choice, it will be a necessity, he adds.
its soul. Previous generations of towers “As space becomes more and more
were predominantly places to work. They precious, shared amenities that have a
were hives of activity by day, and dark and higher utilisation will be more important,
silent by night, set in downtown areas that compared to lots of individual amenity
became ghost towns after working hours spaces or private spaces. Strategies
and at weekends. The new tower is a far that increase the utilisation of space
more sociable place, buzzing well into the will be important, whether that’s shared
night, if not 24/7. It plays a more active atrium spaces, hotel lobbies that serve as
role in the local community, and perhaps restaurants or office lobbies that serve as
even functions as a community itself. meeting areas.”
High-rise buildings are increasingly Older towers provided little at ground
combining a mix of different kinds level beyond hostile, high-security
of space, at least some of it publicly entrances and high winds. Today,
accessible. The taller a building is, the more planners are demanding much more,
likely this is. According to the database of and developers are increasingly aware
the Council for Tall Buildings and Urban of the value of a high-quality experience
Habitats, 17% of buildings over 150m are at ground level. Even pure commercial
mixed-use. But this rises to nearly half of all towers are likely to include some food
super-tall towers over 300m, and three- and beverage or retail space at their base.
quarters over 500m. Or they may be just one component of a
Mixed-use makes sense for economic more varied development, as at Hudson
reasons – there’s a lot of space to fill in a Yards, linked by a shared plaza or publicly
mega-tall tower and selling residential units accessible podium.
can help to finance the rentable elements “In our rekindled love affair with
– and also practical ones, because higher skyscrapers and the city, we need to
floorplates tend to be smaller and so less think about the spaces and communities
suited to commercial use. we’re creating at ground level,” says
But it also makes sense because life in Ken McBryde, principal at HASSELL
24-HOUR

cities is changing. The new generation in Sydney. “The skyline of a city is

TOWERS

of workers are returning to urban areas, predominantly an abstract thing – it exists

rejecting suburban lifestyles in favour in the digital or photographic realm but
of vibrant neighbourhoods with a range you never actually experience it unless
of amenities. Millennials already make you’re in a helicopter. We need to address
up half of the US workforce, points out the challenge of creating meaningful
Andrew Cantor, vice president at Related, and memorable public domain, as
co-developer of the Hudson Yards that’s what will determine whether the
regeneration scheme in New York. “By building becomes an important social and
the time that it’s complete, they’ll make commercial asset to the city.”
AS CITY LIFE CHANGES, TALL up 75%. They’re looking for a mixed-
BUILDINGS CAN’T JUST BE PLACES use experience in their neighbourhood.
Millennials increasingly want a dense urban
TO WORK. THEY NEED TO BE PART quarter with a real mix of uses – areas that
are buzzing and active at all times, and
OF THE NEIGHBOURHOOD where the lines between your office, your
hotel, your restaurant or your residence
are blurring.”

06 07
 China Zun Tower, Beijing A high-rise building not only changes The ability to respond to fast-changing One of the most significant challenges
DESIGNING SKYSCRAPER CITIES ///

THE RENAISSANCE OF TALL //

Image courtesy of KPF
the skyline today, it also forms part of the workplace trends is also key to maintaining that all buildings will face in the relatively
legacy that we leave to future generations. the longer-term value of a building. near future is the impact of climate
Conventional real estate wisdom gives a Technology is already removing the change – a moving target as the century
commercial building a lifespan of around need for large support spaces, points out progresses. How will buildings and their
30 years. But the sheer scale of high-rise Andrew Cantor, vice president at New surroundings be affected by much heavier
structures and the quantity of materials York developer Related. “There will be rainfall or more frequent droughts, what
and energy that go into them means they no need for large file rooms or storage toll will more frequent extreme events
will be around for much, much longer, rooms as there has been in the past, and take on structures and façades, and how
with lifespans measured not in decades even servers have diminished in size or to maintain comfortable conditions
but in generations. been moved off site into the cloud. So the for building occupants when average
amount of space each person needs to temperatures could be much higher
Super-tall and super-slender buildings
work is smaller and there’ll be more people than today? “The challenges that climate
need to be extremely strong. Elements
on each floor, putting pressure on elevators change will pose need to be considered in
such as cladding or mechanical and
and washrooms.” every building, but particularly those that
electrical systems may be upgraded, but
The challenge is not just to size building will be around for a long time,” says David
their immense structures are effectively
systems for potentially greater loads but to Symons, director of Environment & Energy
permanent features of the urban
keep structural elements as unobtrusive as at WSP | Parsons Brinckerhoff in the UK.
landscape. In this way, today’s state-of-
possible, with no columns on the floorplates “In 50 years, peak summer temperatures
the-art towers have more in common with
and floor-to-ceiling windows so that spaces in London are forecast to be 6.5°C higher
medieval cathedrals than with their low-rise
can be reconfigured any way a tenant than they are today. By 2100, they could be
contemporaries. “In the history of the
wants. The same goes for residential towers around 10.5°C higher. Our research shows
world, only four buildings taller than 150m
– internal columns interrupt views and limit that today’s building design codes are
have ever been demolished,” says Bill Price,
buyers’ options. wholly inadequate to address these future
director at WSP | Parsons Brinckerhoff in
temperatures. Over 80% of Londoners
London. “For a large building in an urban The economic challenges of mega-tall
already claim their flats are too hot in
setting, studies show that it will cost more towers mean that they may sometimes
summer, with newer homes having
more of a problem.”
To address hotter temperatures,
mechanical and electrical engineers
“IN 50 YEARS, PEAK SUMMER TEMPERATURES could just design larger cooling
systems. “But that will create massive

IN LONDON ARE PREDICTED TO BE 6.5°C extra energy demand – for cities

and for building owners. That’s
challenging when energy prices are
HIGHER THAN THEY ARE TODAY. BY 2100, forecast to be about 30% higher in
the UK by 2030. So energy bills will
THEY COULD BE AROUND 10.5°C HIGHER” be much higher too.” The alternative
is to use emerging techniques
DAVID SYMONS, WSP | PARSONS BRINCKERHOFF that use fresh air from outside and
the thermal mass of buildings to
maintain comfortable temperatures.
“That becomes even more of an
and take longer to take it down than it did undergo drastic changes of use even when option in a future world which is anticipated
to put it up. That means that when we’re the design is well advanced – keeping to be purely electric. By 2050, some cities
designing and constructing a tall building, building systems engineers on their toes. will be all electric for heating, for power,
we need to remember that it’s essentially Now under construction, 528m China for travel. At a stroke, that transforms
going to be there forever.” Zun Tower in Beijing was originally air quality and reduces noise levels.” In
planned as a mixed-use development temperate climates today, windows remain
Price suggests that designers should
providing 380,000m2 of offices, hotel shut against the noise and pollution of city
think more carefully about how a building
FUTURE

accommodation and serviced apartments. streets, and because buildings are designed
might eventually be demolished from
The biggest challenge for the services to rely on air conditioning systems. “But
the start. But more immediately, they
READY

engineers was always reconciling the unique why would you do that into the future? You
need to make sure towers can adapt to
form of the building – flared at the base could imagine a world in which there’s no
change, and consider a range of interlinked
and the top – with the demand for services reason not to open the windows.”
technological, social and environmental
factors that will impact on the built and vertical transportation created by its Driverless cars promise to change
environment. mix of uses. Then the decision was taken to patterns of land use in cities too: “At the
STRUCTURES AND SERVICES OF There are good commercial reasons
convert the whole building to commercial moment, quite large amounts of valuable
space. “This dramatically increased vertical space are given over to car parking,” says
SUPER-TALL BUILDINGS MUST BE for designing flexible spaces too. Office
transportation requirements, but the Symons. “In the future, at the very least
buildings need to be able to accommodate
ABLE TO ADAPT TO CHANGING different occupier groups to make them as
construction was already fixed, so it wasn’t
possible to make any changes to the
you could have much tighter parking
spaces because the cars park themselves.
USES, AND A CHANGING PLANET lettable as possible. Because corporates
are increasingly seeking more locations
available space in the core,” says Vincent At best, you don’t have car parking at all
Tse, managing director of building systems in the building – if you do drive yourself
that offer more diverse experience for
for WSP | Parsons Brinckerhoff in China. to your tall building, the car then goes
their workers, they need to attract novelty-
“Our solution was to add more sky lobbies, off and parks itself on some cheap land
seeking millennials and to spur cross-
so there are now three double-decks somewhere else and comes to you
disciplinary thinking and innovation.
spaced throughout the building.” when you need it.”

08 09
 school and public space
DESIGNING SKYSCRAPER CITIES ///

THE RENAISSANCE OF TALL ///

and no fewer than 16
skyscrapers.
“When you provide
mass transit access to a
neighbourhood, it spurs
“I THINK THERE ARE SOME VERY BRIGHT DAYS tremendous development
opportunities,” says
IN FRONT OF US IN TERMS OF HOW CITIES ARE Kelly. “The absence of
access really limited
BEING PLANNED AND DEVELOPED, ACROSS that neighbourhood for
a very long time. After
THE US AND AROUND THE WORLD” the decision was made
to extend the subway,
development naturally
GREG KELLY, PRESIDENT & CEO, WSP | PARSONS BRINCKERHOFF
followed.” WSP | Parsons
Brinckerhoff is also
involved in similar railyard
projects elsewhere, such
as the 22-acre Atlantic
Yards site in Brooklyn, now
Traffic congestion and pollution were In many places, towers are being renamed Pacific Park, and
almost defining characteristics of the deliberately sited on top of or next another project in Boston.
20th-century city. Urbanisation has been to existing transport hubs, he notes, For best results, the interfaces between
traditionally accompanied by an increase while investment in new infrastructure infrastructure and buildings are considered
in car travel, choking roads and bringing is creating opportunities for high-rise at the earliest possible stage, says Kelly.
movement to a near halt for significant development. London’s Shard is right next “That’s vitally important. Obviously you
portions of the day. The most valuable to a major interchange for overground don’t want to preclude future options to
development sites were ones that could and underground trains and buses, while maximise the overbuild that could occur
be easily reached by car from the suburbs San Francisco’s future tallest building, the over a subway station, but it’s also about
and had ample room for parking. 326m Salesforce Tower, will be part of the creating successful communities. You
As more and more people move to new Transbay Transit Center complex. This have to look at the pedestrian flows, how
cities, the challenge of mobility is only includes more than 6 million ft2 of office the traffic interacts with the pedestrians
becoming more acute. UN HABITAT space, 4,400 homes, a hotel and retail and how that knits together with the
estimates that by 2050, city dwellers space, as well as a 5.4-acre rooftop park. high-rise development. The sooner you
could travel three or four times as many Developers are also looking afresh can bring those two together, the more
passenger-kilometres as in the year at previously unappealing sites close to efficiently you will be able to incorporate
2000, and that freight movement could transport hubs. Areas that were once both parts of the development and the
rise more than threefold over the same blighted by their proximity to rail lines or better the outcome will be. With little or no
period. Without investment in sustainable left as underused expanses of industrial additional cost you can enhance what that
alternatives to cars, the places where three- space are now prime opportunities for neighbourhood looks like.”
CONNECTED

quarters of the world’s population live, work high-rise development. They are able The integration of transport and high-
and play will simply be unable to function. to support sustainable high-density density development is good news not
“Higher-density cities won’t work development, and the potential returns only for those components but for the
without investment in transport,” says Peter from building tall mean that overcoming success of cities themselves, believes Kelly.
Weingarten, principal at Gensler. “As the the challenges of such sites becomes an “I think the industry is getting very smart
world is getting flatter and there’s a war economically viable proposition. at how we plan cities. It goes beyond the
for talent, people will migrate like they’ve “These transport nodes do present transit infrastructure. We’re looking also at
never migrated before. Cities that don’t technical challenges, because you have how we plan the environment, at how we
have good infrastructure will lose out to to keep a railroad running while you’re power cities, I think there are some very
places that do.” building around it,” says Kelly. “That takes bright days in front of us in terms of how
One of the major themes of 21st-century time and may involve additional cost, but cities are being planned and developed,
urbanisation will be investment in systems by being in that location, there’s a greater across the US and around the world.”
such as metros, light rail and bus rapid long-term value that’s created. People may
transit, as city planners search for more have been a little bit reluctant in the past,
sustainable ways to support growth. The but I think they now truly see the value of
population of a super or mega-tall tower it and they’re moving forwards with these
THE DENSE FABRIC OF 21st-CENTURY can easily rival that of a small city in itself, so types of project.”
it needs to be integrated closely into these This is the story of the US’s largest
CITIES MEANS THAT TOWERS NEED TO networks. “Mass transit links are critical to ever real estate project, now underway at
BE CLOSELY INTEGRATED INTO PUBLIC successful high-rise development,” says
Greg Kelly, president and CEO of WSP |
Hudson Yards in New York. The extension
of the subway to the western edge of
TRANSPORT NETWORKS Parsons Brinckerhoff in the US, Central & Manhattan has suddenly opened up the
South America.. development potential of a neglected
industrial site. Over the next ten years,
it is set to become a 28-acre mixed use
development of office, residential, retail,

10 11
DESIGNING SKYSCRAPER CITIES ///

THE RENAISSANCE OF TALL ///

The Shard, London Halvorson says this has partly been Many more towers also combine a mix
driven by advances in building core of uses, which is giving rise to innovative
construction, specifically mechanisation hybrid structures. London’s Shard, for
which reduced the amount of labour example, features a highly unusual
involved and made concrete or composite combination of both steel and concrete
structures more economical than pure floors around a concrete core. The first 40
steel. “But an even more important driver storeys are offices, supported by steelwork
is that architects, owners and occupiers spanning from the core with steel columns.
The typical 20th-century skyscraper was wanted more glass and more windows As the floorplates shrink, the use switches
most likely to be an office, and probably without those big structural obstructions to hotel and luxury apartments and the
built out of steel. It’s much harder to on the perimeter.” A concrete core frame to post-tensioned concrete, before
characterise the 21st-century model. provides a strong but discreet backbone reverting to steel for the spire. Using
Encompassing a diverse range of uses for the building, while protecting essential concrete for the middle section enabled
and a multitude of unusual shapes, every services and means of egress and the addition of two extra storeys within the
one of today’s towers is a prototype, concealing key structural elements such as overall height.
demanding constant innovation. outriggers on plant floors.
Structures need to perform better than In New York’s new super-slender
ever before, but also be less obtrusive. Halvorson thinks hybrid structures will residences, high-strength concrete cores
The structural engineering of skyscrapers continue to evolve, as engineers keep and frames maximise strength without
was a source of pride and wonder in up with the computer-aided ingenuity restricting internal layouts or blocking
the early 20th century, proudly flaunted of an ever more ambitious architectural views. But for the most extreme aspect
on steel column façades. Now the profession. “If you look back to the 1980s or ratios, strength alone is not enough.
engineer’s greatest feat is to keep well earlier, buildings were rectangular and they Engineers cannot keep adding structure
out of sight, creating super-strong were largely prismatic – they were constant indefinitely – they have to think laterally.
structures that betray no trace of the from top to bottom or they had a constant A key innovation of recent years is the
massive forces at play. slope or regular setbacks. Geometries were use of dampers, which function in a similar
very simple. Now we’re trying to develop way to the shock absorbers on a car to
This requirement for hidden strength structural concepts for buildings that taper
has contributed to a radical shift in what help buildings perform better under wind
and slope, that have 3D curved or irregular and seismic events. “We used to design
towers are constructed from, says Bob surfaces, or large openings through them.
Halvorson, executive vice president structures that were basically passive,” says
The biggest challenge we have is adapting Halvorson. “Today there are a lot more
at Halvorson and Partners. In 1984, structural tools to more creative, taller and
Halvorson wrote a paper on the structural options open to the engineer for ‘active’
thinner architecture.” buildings with dynamic elements that
solutions most commonly used for tall
buildings. “If you looked at all the tall Another major factor in the shift modify their behaviour in positive ways.”
buildings up to that point, particularly from steel to concrete is the increasing As towers get taller and thinner, the
office buildings, they were structural steel. proportion of towers designed wholly or biggest challenge for the engineer is
They’d have either diagonal bracing or partly for residential use. Concrete is the not making them sufficiently strong and
closely spaced columns and a moment natural choice for apartment buildings, resilient, but cost-effective, says Silvian
frame round the perimeter, and that because it offers better acoustic and Marcus, director of building structures,
seemed to be the way of the future.” But fire separation between apartments and WSP | Parsons Brinckerhoff in New York:
when he repeated the exercise 20 years enables shorter floor-to-floor heights “Any engineer can design a structure that
STRUCTURES

later, the world had completely changed. so developers can fit more storeys will stand. The brilliant part is to do it in an
“The tallest buildings were either concrete within a constrained building envelope. efficient way.”
or of composite construction using both “Apartments are always going to be
steel and concrete, and the structural concrete-framed,” says Mark Hennessy,
systems had almost universally switched director of structures at WSP | Parsons
from the perimeter of the building to Brinckerhoff in Melbourne. “Floor-to-floor
structures hidden in the core.” heights can be pretty lean and mean,
whereas steel just doesn’t work from that
point of view.”
HYBRID

“NOW WE’RE TRYING TO DEVELOP

TODAY’S SKYSCRAPERS NEED TO BE STRONGER THAN STRUCTURAL CONCEPTS FOR BUILDINGS
EVER BEFORE – AND WHILE THEIR ARCHITECTURE IS THAT TAPER AND SLOPE, THAT HAVE 3D
INCREASINGLY STRIKING, THE STRUCTURES CURVED SURFACES, OR LARGE OPENINGS
THEMSELVES MUST BE CLOSE TO INVISIBLE
IN AND THROUGH THEM”
BOB HALVORSON, HALVORSON AND PARTNERS

12 13
 Salesforce Tower, San Francisco
DESIGNING SKYSCRAPER CITIES ///

THE RENAISSANCE OF TALL ///

Image courtesy of Hines In tomorrow’s denser cities, people will There is also a powerful business Maximising fresh air in office spaces
spend a much greater proportion of case for better environments that can also requires a different approach to the
their lives in tall buildings. But having a boost workers’ productivity – staff costs façade – as a permeable skin rather than
connection to the outside will be more can account for as much as 90% of a an impenetrable barrier. Simply opening
important than ever. Traditional office company’s outgoings, so even a small the windows is not an effective ventilation
towers are sealed against the elements improvement can make a big difference. strategy for buildings with deep floorplates,
and use building systems to create a Studies have found that office workers says Nick Offer, director at WSP | Parsons
comfortable environment, but the next with a window seat sleep an average Brinckerhoff in London – the air current
generation will be far more permeable, of 46 minutes longer per night and will either be too strong by the windows or
a trend driven by both employers and that doubling the supply of outdoor too weak further in. “What we need is an
workers themselves. air to an office reduces short-term sick equivalent to openable windows, without
“One of the most important things we leave by 35%. In 2014, the World Green actually opening them. We need to link the
can do as buildings get taller and higher Building Council brought a growing building to the façade, floor by floor. Then
and further from the ground is let the body of evidence together in a landmark we can channel air in through the façade,
occupants keep in touch with the outside, publication called ‘Health, Wellbeing & into rooms on each floor, and then push
so they can understand what time of day Productivity in Offices, the next chapter that fresh air through the floors or ceilings
it is and what’s it like before going out, for green building’, which received to service the space.”
says Ken McBryde, principal at HASSELL enthusiastic backing from industry clients The Salesforce Tower in San Francisco
in Sydney. “That’s a real challenge in tall including Tishman Speyer, British Land and will be ventilated with outdoor air for
buildings, because if you can’t open the Grosvenor. 80% of the time, supplied from under
windows, you really lose touch with the There’s even a new certification, the the floor. It has been pre-certified LEED
environment.” WELL Building Standard, which focuses Platinum, making it one of the world’s most
Quality of life has taken on much exclusively on human health and wellbeing. sustainable tall buildings. In temperate
greater importance among the millennial In March 2015, the developers of 425 Park climates, using outside air also reduces
generation – and as they spend so much Avenue committed to build New York’s the energy that a tower consumes, which
time in the office, that means quality first WELL-certified office tower. Cooper will make it an increasingly appealing
of the working environment. “It’s becoming says that clients have begun to ask strategy as energy costs rise in the future
about much more than temperature,” about the standard, and a couple have and targets on carbon emissions become
says David Cooper, president of the requested that their buildings comply, tougher. In most parts of the world, it is
US buildings division at WSP | Parsons but it’s still some way from achieving possible to completely ventilate a building
Brinckerhoff. “It’s about total environmental widespread adoption. using external air for 70-80% of the year,
comfort – access to natural light, glare In a tall building with a huge population, says Offer. “There is a great future in
control, air motion and humidity, the creating a healthy environment starts thinking differently about how we design
freshness and quality of the air. This is with the building envelope. “The envelope true low-energy buildings.”
absolutely, increasingly important to a is the critical juncture for thermal Introducing higher levels of fresh air
successful occupancy.” performance, access to daylight and views, makes denser working environments
glare control, and all of those things really possible – typical occupation densities
affect comfort,” says Cooper. “There have fallen from 10m2 per person to 8m2.
are many opportunities, depending on “Because of changes in screen and lighting
the climate – dynamic façades, operable technology, we are able to squash up
façades, triple-wall façades, dynamic and and people accept it because they like
static shading. That’s where engineering collaborating and working together,” says
and architecture meet.” Offer. “But they also need access to other
PERMEABLE

types of great space, so they can break

away from their desks and meet other
people or find a quiet place to work. It’s
about the building giving something back
other than office space.” Green spaces
make vertical cities much more pleasant
places to be, just as they do horizontal
ones: Shanghai Tower, China’s tallest
SPACES

building at 632m and one of its greenest,

has winter gardens at the edge of every
floor, open spaces with trees and planters.

“IT’S ABOUT MUCH MORE THAN From a developer’s point of view, this is a
significant space sacrifice, which is why the
most advanced buildings are typically one-
AS PEOPLE SPEND MORE TIME FURTHER FROM TEMPERATURE. IT’S ABOUT ACCESS TO off landmarks or constructed for owner-
THE GROUND, ENVIRONMENTAL COMFORT occupiers, says Cooper. “Most innovation

IS MORE IMPORTANT THAN EVER. THAT MEANS NATURAL LIGHT, GLARE CONTROL, AIR happens in owner-occupied buildings,” he
says. “But then it catches on and becomes
BRINGING THE OUTDOORS IN MOTION AND HUMIDITY, THE FRESHNESS something that other tenants are looking
for because they see the advantages, and
AND QUALITY OF THE AIR” developers follow suit.”

DAVID COOPER, WSP | PARSONS BRINCKERHOFF

14 15
 THE SKY
DESIGNING SKYSCRAPER CITIES ///

THE SKY AND OTHER LIMITS ///

very week,
E 1 million people “IT’S A FANTASTIC CHALLENGE, LIKE RACING A

AND OTHER
move to cities – if
all of that growth happened
in one place, it would create
12m YACHT. YOU’RE ALWAYS TRYING TO UNDERSTAND
a new city the size of Dublin,
New Orleans or Adelaide.
THE RULES AND WHAT THE POSSIBILITIES ARE.”
But in reality, a considerable DAVID PENICK, HINES

LIMITS
proportion of these new city
dwellers will be looking for
space to live, work and play For developers, the Penick welcomes the In New York, getting a
in places that have been challenge is to carve out viable complexity that the city’s project off the ground is not
established for hundreds schemes from a constantly detailed planning guidelines just about finding the right
or thousands of years. The diminishing supply of land. bring. “An exciting thing about site – the vertical space above
densification of historic New towers must be woven developing in New York is that it is just as sought-after. To
cityscapes will be one of into an already complex there is a great set of rules. make 53W53 possible, Hines
the defining challenges tapestry of existing buildings, It’s not a matter of going to also had to negotiate the
of the 21st century. much-loved landmarks, public City Hall and saying ‘Gee, transfer of air rights from
spaces and transport and utility I wish I could do this’. Every neighbouring buildings that
IN ESTABLISHED CITIES, NEW TOWERS ARE NEVER BUILT For city planners, the
networks. If buildings define neighbourhood is precisely had not consumed their full
challenge is one of balancing
IN ISOLATION – THEY ARE INTIMATELY SHAPED BY THE the interests of many different
a city, they are themselves
shaped by all of the forces in
zoned, and for each plot, it says
how big the building can be
entitlement, says Penick.
“Then there are other air rights
stakeholders, enabling cities to
BUILDINGS AND SPACES AROUND THEM. DEVELOPMENT thrive and grow without losing
that city. and what its use can be. It’s a transfers within the project to
fantastic challenge, like racing a allow for the intended uses to
IS A COMPLEX JIGSAW OF ZONING RULES, VIEWING what makes each one unique. The profusion of sculpted,
chiselled or staggered forms 12m yacht. You’re always trying occur at their correct locations
In a fully globalised economy
CORRIDORS AND AIR RIGHTS. BUT IT’S A CHALLENGE where skills, jobs and capital now cropping up in established to understand the rules and
what the possibilities are, and
within the building. It’s a very
demanding process.”
urban cores is not only an
THAT DESIGNERS ARE MEETING HEAD ON are increasingly footloose,
the fiercest competition for expression of the whims of then someone comes up with a The plans also had to be
architects or the quest to create clever new idea that everyone signed off by a number of
resources is being fought
‘iconic’ landmarks. It’s also learns from.” parties including the Museum
not between countries but
between rival cities. High-rise because in the most congested One of the most striking of Modern Art, which will
buildings play an important role cities, attempts by city planners features of 53W53 is its high occupy the lower floors, the
not only in accommodating to protect rights to light or height-to-width ratio – a Landmarks Preservation
newcomers but in attracting signature views often impose feature of many new towers in Commission and the NYC
them in the first place – very restricted, contorted Midtown. As developers seek Transit Authority because of
expressing a city’s personality envelopes into which buildings to achieve the greatest possible the nearby subway tunnels.
and marking it firmly on the must fit. value from very narrow, yet The project will be occupied
map as a destination for talent It didn’t take New York very expensive plots, advances in 2018, 11 years after Hines
and investment. planners long to notice that in structural engineering are originally purchased the land.
its new skyscrapers were enabling increasingly slender New York is already
overshadowing the streets forms. But 53W53 also lies in renowned as a skyscraper
below and to restrict building three different zoning districts, city, but London is only now
massing at certain heights, each with its own permitted becoming one. Around 70
at a stroke prompting the densities and shapes. Architect buildings above 20 storeys
distinctive setbacks of many of Jean Nouvel’s design is an are under construction, and
the city’s Art Deco landmarks elegant solution to a complex almost 200 more have been
from the 1920s and 30s. geometrical problem, with proposed. But even while some
Since then, as approaches to different parts of the building Londoners may feel uneasy at
planning have become more tapering at different angles what seems like untrammelled
sophisticated, the challenge for as it rises from 53rd and 54th development, there is a well-
developers has only become Streets. defined set of rules governing
more complex. “Government the placement and form of
approvals are a huge piece of towers, intended to preserve
what we do,” says David Penick, views of the city’s landmarks
managing director of Hines, from surrounding public
developer with Goldman Sachs spaces. As these new towers
and Pontiac Land Group of take shape, London’s planning
the super-tall 53W53 tower rules are being writ large on
above New York’s Museum the skyline.
of Modern Art. “To create
a project like this, we spend
a tremendous amount of
time getting everything in
place so we can proceed with
construction.”

16 17
 “DEVELOPING IN LONDON IS QUITE
DESIGNING SKYSCRAPER CITIES ///

THE SKY AND OTHER LIMITS ///

A CHALLENGE BECAUSE THERE’S A
VERY HISTORIC STREET PATTERN AND
BLOCK SIZE, AND A LOT OF PROTECTED
VIEWS. IN THE RECENT PAST, A LOT
OF BUILDINGS HAVE BEEN SHAPED TO
DEAL WITH THOSE CONSTRAINTS”
GEOFF HARRIS, TH REAL ESTATE

18 19
DESIGNING SKYSCRAPER CITIES ///

THE SKY AND OTHER LIMITS ///

The protected view of architecture to be defined by
St Paul’s Cathedral from Fleet this requirement. Our focus
Street is one of the biggest was on creating a group of
reasons why the 220m-high simple, well-proportioned
Leadenhall Building tapers elements which work on the
at a 10° angle, earning it the skyline. The Fleet Street view
nickname ‘the Cheesegrater’ requirement was handled
and why its future neighbour by working a set of terraced
A model showing the available envelope in which 40 Leadenhall Street had to sit.
at 52 Lime Street, ‘The set-backs into the overall
Below is Make Architect’s terraced design Scalpel’, leans back in the composition, which also
opposite direction. In this way, enhance the workplace with
both remain hidden behind external amenity spaces.”
the cathedral dome. This There is a long history of
same view was also a key city dwellers giving irreverent
consideration in the design nicknames to new buildings.
of 40 Leadenhall Street, a Now with an array of irregular
910,000ft2 development of forms rising above their
between seven and 34 storeys hoardings and a constant
that sits to the east of The stream of proposed towers
Scalpel. coming to market, Londoners
But here, developer TH have gone into overdrive.
Real Estate wanted to take a Within minutes of a building’s
different approach, as head launch, there will be a heated
of development Geoff Harris competition on social media to
explains: “Developing in coin an appropriate name. The Toronto skyline
London is quite a challenge In future, London’s towers
because there’s a very historic may be less easy to name as
street pattern and block size, architects and developers take
and a lot of protected views. a more understated approach.
In the recent past, a lot of Gwyn Richards, the City of
buildings have been shaped London Corporation’s head
to deal with those constraints. of design, said in a recent
We were looking for a building
that is beautiful, unique and
distinctive in its form, that
interview that he wanted to
see “less iconic buildings, less “IS EVERY BUILDING SUPPOSED TO BE AN
takes us back to 20th-century
US tower design – a building
provocative buildings, fewer
buildings which might have
nicknames”.
EXUBERANT TOP OR SHOULD SOME BE
that expresses its verticality,
mixes solid and clear and
But that hasn’t saved
40 Leadenhall Street from
MORE CONSERVATIVE? ”
uses terracing.” JAMES PARAKH, CITY OF TORONTO PLANNING DIVISION
becoming known as “Gotham
Working with Make City”, a name originally coined
Architects, Harris’ team by Richards’ predecessor Peter
completed 58 separate design Rees. Harris says he doesn’t
studies, modelling all the mind. “Actually, I quite like it. It’s
constraints in 3D to produce an Developers themselves the UK. “They’re more blasé. Toronto Planning Division. San Francisco has the Golden
interesting because we were
envelope in which the building may now come to market In London, it’s a relatively new “We think very hard about Gate Bridge and the bay. Hong
aiming for that 20th-century
had to sit. But rather than with a brand already formed, phenomenon but in time the the role of each tall building Kong has Two International
US architecture and that has
shaping the building to fill that as WRBC has done for The novelty will wear off here too.” on the skyline,” he says. “That’s Financial Centre, Victoria
come through. But we won’t be
Scalpel. This is partly a way of Harbour and The Peak in the
“WE ENDED UP WITH A space, they considered it from
the inside out, looking at how
form could follow function.
writing ‘Gotham City’ on our
hoardings.”
heading off any less flattering
suggestions. But naming these
Few cities are densifying
as rapidly as Toronto, which
has more than double the
really important. Is every
building supposed to be
an exuberant top or should
background. Rio de Janeiro is
instantly recognisable for its
TERRACED BUILDING THAT “We ended up with a terraced
building that is arranged in
Sometimes a building’s
owners may adopt a
giant buildings also makes
them relevant on a human
number of high-rise buildings
under construction than New
some be more conservative?
Not every building can be a
statue of Christ the Redeemer
and Sugarloaf Mountain.
IS ARRANGED IN SLICES. slices,” he says. “It deals with
all the constraints, but it’s
nickname officially, as Sellar
Property Group did at The
scale, and somehow less
threatening.
York, with as many as 180
tower cranes complementing
landmark.”
Parakh has noticed some
Toronto’s official plan
identifies centres in which
IT DEALS WITH ALL THE still a very clean form that is
rectilinear.”
Shard – originally coined by
conservation body English
Heritage as an insult. If it does
“People don’t do this to
the same degree in New
a burgeoning forest of
skyscrapers. Over the last
common characteristics among
the most successful global
growth will be concentrated,
on which streets the tallest
CONSTRAINTS” “40 Leadenhall has to be
unseen from Fleet Street,
stick, a nickname can be a
badge of genuine landmark
York because it’s already an
established high-rise city,”
decade, its skyline has been
transformed under the close
skylines: “Very often, there is
a series of buildings, and then
buildings should be located,
and sets viewing corridors
GEOFF HARRIS, TH REAL ESTATE by sitting behind the dome points out Bill Price, director at eye of James Parakh, urban one landmark that’s different, to protect landmarks such
status: few would recognise the
of St Paul’s Cathedral in the WSP | Parsons Brinckerhoff in design manager at the City of and then a natural feature.” as the dome of the Rogers
Gherkin by its official name of
same way as The Scalpel,” 30 St Mary Axe.
adds James Taylor, partner at
Make. “But we didn’t want the

20 21
DESIGNING SKYSCRAPER CITIES ///

THE SKY AND OTHER LIMITS ///

10,000 people there when it’s HASSELL recently won front. “We reorganised the
finished and they all need food a competition to design streets, we replanted it and put
and drink,” says Harris. “The 60 Martin Place in Sydney, seating in, and we lifted the
City of London is a busy area a 32-storey tower due for building up 9m so that a public
so offering good amenities is completion in 2019. The design street can run through the site
very important.” team have tried to integrate it underneath. Rather than the
‘Placemaking’ has become into the cityscape in a range of building lobby occupying the
an important pastime for ways, opening up a previously middle of the site, it connects
developers in recent years, not obstructed view of St Stephen’s the square and the street. You
only to satisfy planners but also church, and connecting the can walk through there, sit
because they recognise the building with the surrounding down, get a drink of water and
commercial benefits of making spaces at several different no one will stop you.”
a location more ‘sticky’. After levels. They have also created EPA is now applying this
all, potential office tenants a generous ‘civic room’ that concept to a much larger
or apartment buyers have an invites the public into the project: No 1 Undershaft,
increasing choice of rooms ground plane, including a a super-tall tower opposite
with a view, and an attractive publicly accessible roof space the Gherkin. Though the
neighbourhood at ground on the podium level that will 294m-high project will be the
level can be a crucial point of contribute to the night-time tallest building in London’s
differentiation. activity of Martin Place and financial quarter, the starting
Macquarie Street. point is the human scale. “In
“As these buildings get
larger and more and more Get the city-making agenda a city like London, you’ve got
dominating, I think it’s incredibly right and asset values can to understand how people
important that we talk about climb, says McBryde – the move. We carry out pedestrian
this more,” says Ken McBryde, challenge is to create spaces studies to map that movement,
principal at HASSELL in that genuinely feel as if they and the challenge for us is how
Sydney. “To make our cities belong to the public on what is to change it.”
habitable, buildings need to really private land. The scheme will see the

“SYDNEY OPERA HOUSE IS UNIVERSALLY work on a community level.”

For McBryde, ‘groundlines’
This interface between
private and public will
continue to test project teams,
redevelopment of an older
tower completed in 1969,
a 118m-high block inserted
RECOGNISED BUT THE MOST SUCCESSFUL THING are as important as skylines,
and it is a building’s presence
at street level that determines
especially as tall gives way to
super-tall. “As buildings get
clumsily into the winding
street pattern. EPA wants the
IS THE GROUND PLANE. IT’S REALLY BUZZING” whether it is a successful
addition to a cityscape. He uses
bigger, their cores become
more demanding,” says Nick
new building to work more
harmoniously with the existing
KEN McBRYDE, HASSELL the example of the Sydney Jackson, director at Eric Parry city, and restore some of the
Opera House, a world-famous Architects. “The segregation of older connections between
landmark. “It’s universally uses and of entrances becomes the surrounding spaces. “There
recognised as a symbol of the more of a problem and security are two 16th-century churches
city, but the most successful is a much bigger factor. That that probably haven’t seen
thing is the ground plane, makes it very difficult in terms each other for 300 years,” says
Centre stadium. It’s designed style, and even though they committee, which is working on
the podium and the way it of how you land a building. Jackson. “We want to remove
to preserve the integrity of the are dwarfed by tall buildings, a publication about the spaces
sits in the city. At all times of One of the problems we see that blockage and replace it
skyline as the city develops, there has to be some balance. surrounding tall buildings, due
the week, this place is really as we look at many of the tall with a more delicate footprint.”
but the way buildings integrate Thinking about one without out in 2016.
buzzing.” buildings going up around the A super-tall giant that treads
into the city at ground level the other is not making a great This is also a theme for 5 Aldermanbury Square, London world is that they can be very lightly on its surroundings:
is an equal focus for Parakh: city.” Richards at the City of London He thinks that’s also why
aggressive and alienating at perhaps that should be a model
“You can’t ignore how these Toronto’s first super-tall Corporation. To gain planning Londoners have embraced
ground level.” for high-rise development
buildings meet the street. project has just been approved, approval, he says, new towers The Shard, even though it’s
We’ve spent a lot of time on an unprecedented scale To create more permeable everywhere.
the Mirvish+Gehry proposal will ideally have some public
thinking about the scale of the for the city. “The success of spaces, designers may need
for twin residential towers, at space at the top, and definitely
individual in relationship with
the tall building.” Buildings
82 and 92 storeys. “It’s going to
play an important role on the
at the base. Accessibility and
permeability at street level is
The Shard is that it’s not an
impenetrable tower, it’s actually “WE LIFTED THE BUILDING UP to think radically about what
happens at ground level.
must fit within their context
and transition down to lower-
skyline, but approval was based
on preserving heritage and
a must. At 40 Leadenhall, for
example, the ground floor plate
highly permeable. There’s a
whole range of mixed uses 9m SO THAT A PUBLIC STREET When it was completed back
in 2007, EPA’s Stirling Prize-
nominated 5 Aldermanbury
scaled buildings and open
space. Wind-tunnel testing
is mandated on all projects.
getting adequate separation
distances, adequate light and
has been set back to leave
more pavement and retail
that the public can explore at
multiple levels, starting with
the transport interchange. It’s
CAN RUN THROUGH THE SITE Square was pretty tall for
London. As well as designing
“Parks and historic landmarks
are very much part of our
privacy.” He is also chair of the
Council on Tall Buildings and
Urban Habitat urban design
space, and there is a restaurant
on levels 13 and 14. “If you just
take this building, there will be
access to the public that makes
this a well-loved building.”
UNDERNEATH” the 20-storey office building,
the practice also completely
NICK JACKSON, ERIC PARRY ARCHITECTS transformed the square in

22 23
DESIGNING SKYSCRAPER CITIES ///

THE SKY AND OTHER LIMITS ///

PUBLIC SPACE IN PRIVATE
TOWERS: THE INVISIBLE
SERVICES CHALLENGE
BY DAVID HEALY, TECHNICAL DIRECTOR,
WSP | PARSONS BRINCKERHOFF

There’s a proliferation of The shapes of many The Shard’s façade is meant

public space at the top of
tall buildings in London, as a
London towers are influenced
by viewing corridors to
to resemble pieces of broken
glass leaning together, so rather
“THERE IS ONLY
requirement of many planning
approvals. For a building
St Paul’s Cathedral. But
this also determines the
than having a standard band
of louvres to get air in and out
ONE VERTICAL
services engineer, the impact
of that space on the building is
internal layouts of a building,
and even its ventilation
of the building, we had to do
something a little bit different.
SIDE ON THE
absolutely huge.
When I was working on
philosophy. When buildings
lean, that has a significant
As the ’shards’ overlap to
create fractures, that creates an CHEESEGRATER,
The Shard, this was a major
challenge because of the shape
effect on the mechanical and
electrical services. There is
only one vertical side on the
opportunity for winter gardens
on the office floorplates, which
are naturally ventilated, and
WHICH ALMOST
of the building. The floorplates
shrink as the building gets taller Cheesegrater, for example,
which almost dictates where
on the plant levels we could
use them to get air in and out
DICTATES
but there are massive peaks
in occupancy at the mid-level
restaurant and the viewing
the core has to go. The public
space at the base and the
of the building. Just one of
the impacts of that is that you
WHERE THE
gallery at the top – so the
greatest concentration is where
need to keep that free of
columns impacts the structural
need to designate a particular
fracture for bringing air in or
CORE HAS
the floorplates are smallest. If
we had followed standard fire
engineering, and that pushes
the core further to the back of
out because you don’t want to
cross-contaminate it. It may TO GO”
escape provisions by using the building. Once you offset not be immediately obvious
multiple stairs, there wouldn’t the core, that creates a little to everyone else, but there’s
have been much room left for bit of lower value floor space. some real gymnastics to get
anything else. Our solution was So instead of a ventilation this to work.
that some of the lifts would be strategy where there are central
used in a fire or emergency. air-handling units at the top
That too had a massive knock- and at the bottom, feeding up
on effect, and introduced a through risers, you end up with
range of constraints because on-floor handling units serving
we needed to provide each tenant separately.
pressurised lobbies where
people can wait for lifts, and
install an independent cooling
system for the lift motor rooms
and other elements that would
ensure the lifts could be safely
used in an emergency.

“THE SUCCESS OF THE SHARD IS THAT

IT’S NOT AN IMPENETRABLE TOWER,
IT’S ACTUALLY HIGHLY PERMEABLE”
KEN McBRYDE, HASSELL

24 25
 IT BEGAN WITH A MULTIBILLION-DOLLAR SUBWAY
DESIGNING SKYSCRAPER CITIES ///

FAR WEST SIDE STORY ///

EXTENSION. NOW ONE OF MANHATTAN’S FEW
FORGOTTEN QUARTERS IS THE SCENE OF THE US’S

FAR WEST
BIGGEST EVER DEVELOPMENT: HUDSON YARDS

SIDE STORY
udson Yards is a part of the city,” says Greg a challenge,” says Kelly. “We undertaking improvement
H New York story, a Kelly, president and CEO of wanted to grow Manhattan works across the rest of the
skyscraper story and WSP | Parsons Brinckerhoff and the Far West Side was network. “The MTA had a
an urban regeneration story. in the US, Central & South one of the last frontiers, but pretty full plate with some
But most of all, it’s a transport America, which led the we needed a transportation mega-projects that were very
story – of how a $2.4bn planning and design of the solution.” far along, so this one was going
investment in infrastructure has subway extension and the land Extending the 7 line was to require some innovative
given birth to the largest real use strategy at ground level deemed the most efficient approaches,” says Kelly. “The
estate project that the US has for joint developers Related way to connect the site into question was how we could
ever seen. Companies and Oxford the existing network. Running capture the value of the land
A completely new Properties Group. “That was east to west, the 7 crosscuts that would be developed over
neighbourhood is taking really the underpinning of 18 other north-south lines the next 15 years.”
shape on the western edge this project: using transit as a and serves Grand Central The solution was New York’s
of Manhattan, on a long- catalyst for development. Not Station. From being one of first tax increment financed
neglected railway site next to just to take the subway to the the worst connected parts of project, and one of the largest
the Hudson River. Over the west side, but to use it to create the city, Hudson Yards would undertaken in the US. The
next ten years, that thick forest real growth and an economic suddenly be one of the best. municipal government issued
of rail tracks will disappear benefit for the region.” But constructing the first new bonds to fund the $2.4bn
from view, to be replaced by It all began around the turn section of New York subway in project, which will be repaid
20 million ft2 of office, of the millennium. Although more than 80 years did throw with property tax revenues
residential, retail and leisure the site was only a mile and a up some surprises along the from future developments
space. The masterplan half from the lights and energy way. The 7,000ft (2,133m) in the area. “That provided
envisages 16 tall and super-tall of Times Square, it couldn’t tunnel had to be threaded certainty that the public sector
“WE WANTED TO buildings – all effectively built
on stilts, supported by two
have felt further away. The
problem was accessibility.
through a dense below-ground
network of existing tunnels and
would deliver the infrastructure
improvements that were
GROW MANHATTAN super-strong, highly complex
platforms over the tracks, while
There was no subway line
and it was, at best, a 10 or
building foundations – some of
which were not on the as-built
planned, and that they weren’t
subject to the whims of politics
AND THE FAR WEST the trains continue to roar
on underneath throughout
15-minute walk from Penn
Station, trekking across four
plans. The bedrock in this part
of Manhattan is softer too, so
or policy,” says Andrew Cantor,
vice president of development
SIDE WAS ONE OF construction.
The Hudson Yards scheme is
long city blocks. The Far West
Side lagged behind the rest
the ground had to be frozen
to allow the tunnelling to take
at Related. “Infrastructure
projects typically take longer

THE LAST FRONTIERS, not the first attempt to unlock

the potential of this tantalisingly
of Manhattan on residential,
commercial and retail use,
with around one-third of
place. To minimise the impact
of the station at ground level,
Kelly’s team also used inclined
than any single official’s time in
office. If bonds are issued, there
are contractual obligations that
BUT WE NEEDED A underutilised space, but it is
the first to succeed. What the density elsewhere in the
city, and almost double the
elevators, believed to be a first
for the US.
must be met and that creates
a lot more confidence for
TRANSPORTATION has made the difference is
the city’s decision to extend
the 7 subway line, and the
amount of low-grade garage
and storage space. On a small
The extension required
significant rezoning, as
investors.”

SOLUTION” innovative funding mechanism

that has been used to pay for
island with some of the most
sought-after real estate on the
well as a new funding
mechanism because New
GREG KELLY, WSP | PARSONS it. “Infrastructure has driven planet, it stood out as a major York’s Metropolitan Transport
BRINCKERHOFF vertical development in this missed opportunity. “We had Authority was already

26 27
 Today Hudson Yards is a sea Last year, Related opened residential, hotel, office and will come 30 Hudson Yards, to-ceiling glass in every space like an airport than a New
DESIGNING SKYSCRAPER CITIES ///

FAR WEST SIDE STORY ///

of cranes, with phase one of Abington House just to the retail space. Then there’s the at 1,296ft (395m) the tallest and as many outdoor spaces York subway. Right now, few
the build well underway. The south of the Eastern Yard, a Culture Shed, an expandable building on the site and the as we can build in throughout passengers remain on the
platform over the Eastern Yard luxury apartment building with structure on rails that will host second tallest office building in the buildings. That was a critical train after Times Square, but
section of the site is almost 400 units for rent overlooking large travelling art exhibitions the city. Anchor tenant Time requirement.” the considerable size of the
complete, and 10 million ft2 the High Line. It is fully and New York Fashion Week, Warner has signed up for 38 Public space at ground station offers a clue as to the
of buildings are now coming occupied, and commanding which has committed to of its 90 floors, while at the level is also a key feature of plans for the neighbourhood:
out of the ground. But the the highest rents in Related’s relocate from the Lincoln top, the city’s highest outdoor Hudson Yards. In all, there will when the whole scheme is
Midtown South area around portfolio. “That’s a dramatic Center uptown. There will also observation deck is expected be 14 acres, laid out by British complete in 2024, 65,000
Hudson Yards has already change – it used to be the be a seven-storey mall, where to draw 2 million visitors each designer Thomas Heatherwick. visitors are expected every day.
changed beyond recognition. Upper East Side that had the Related secured something of year. Over the subway station “Getting the public space right “Beforehand everyone said it’s
Five years ago, the anticipated highest rents.” a coup when it tempted luxury itself, 55 Hudson Yards will sit is probably one of the most going to feel too crowded,”
arrival of the subway, combined Abington House looked department store Neiman at the centre of the scheme, important things to make a says Cantor. “Now everyone
with investment in green tall when it was first built, Marcus to open its first New and is being marketed at tech, project feel authentic and says it feels too spacious, which
spaces including the conversion but not for long. Now under York store. professional services and law exciting,” says Cantor. just goes to show that you can’t
of an old elevated rail track construction, 15 Hudson There are three office firms. “Most office space in please New Yorkers. But it’s
The new station at 34th
into the High Line park, began Yards will offer 70 storeys of buildings under construction. New York is more than 50 ready for the development that
Street opened in September
to draw companies including apartments, and be one of The first, 10 Hudson Yards, will years old, so the idea here was is forthcoming.”
2015. Taking the 7 line to
Google, Sony and IAC to the tallest residential buildings open in March, and be home to build something that will be
Hudson Yards is quite an
locate there. It is now growing in the city. 35 Hudson Yards to tenants including L’Oreal, first rate and world class,” says
experience – the slick new
five times faster than the rest will follow in 2019, more than Coach, SAP and Boston Cantor. “That means floor-
34th Street station is more
of Manhattan, and has become 1,000ft tall with a mix of Consulting Group. In 2019,
the number-one destination for
galleries, restaurants and parks.
“Business now recognises
this as one of the most
appealing areas to be,” says
Cantor. “The companies that
are growing in New York are
moving to the west side, for
a variety of experiences you
can have beyond just having
a typical office building.” The
average household income of
the neighbourhood is on a par
with the rest of Manhattan, but
it’s skewed towards a younger,
single demographic, he adds.
“Millennials are really driving
the neighbourhoods that are
coming. They’re looking for
a mixed-use experience, and
that’s what we’re going to
deliver.”

“GETTING THE PUBLIC

SPACE RIGHT IS
PROBABLY ONE
OF THE MOST
IMPORTANT THINGS
TO MAKE A PROJECT
FEEL AUTHENTIC
AND EXCITING”
ANDREW CANTOR, RELATED

28 29
DESIGNING SKYSCRAPER CITIES ///

FAR WEST SIDE STORY ///

55 HUDSON YARDS
SOARING ABOVE
THE SUBWAY
Being close to transport links integration with infrastructure WSP | Parsons Brinckerhoff
is usually a major asset for a and complexity below-grade.” used several tricks to reduce
high-rise development. But 55 Hudson Yards is a the weight of the concrete,
from a structural engineer’s 40-storey tower set back on creating a structure that is light
point of view, there is perhaps a nine-storey podium, which enough to meet strict load
such a thing as being too close. incorporates a six-storey requirements while also being
At 760ft (232m), 55 Hudson ventilation shaft building very strong. They specified a
Yards is not the tallest building for the subway. One of the 12,000psi high-strength mix,
on the site, but it is one of the biggest challenges was how to using lightweight aggregate,
most complicated. It sits not weave the support structure and the floor slabs were
on the Eastern Yard deck, but for all of this through the post-tensioned – a common
on the subway station itself, substantial subway escalators. technique in other markets but
and the brief for the office The tower is mainly supported believed to be the first major
space was also very specific. on 10 caissons, 100ft deep use in New York. At the very
Co-developers Related and with diameters of up to 6ft, top of the building, a system
Oxford Properties Group which had to be driven very of outriggers links the core to
wanted column-free corners, accurately. perimeter columns spaced
a 10-foot clear ceiling and no 30ft apart. All of this allows the
The building was only able to
penetrations on the core floor slabs to be very thin – just
touch the rock below in two
apart from the openings to 9 inches – even with spans of
thin strips that do not even
the elevators. 40ft and 35ft off the core. The
span the whole site. Otherwise,
post-tensioned system was
“All of these things allowed it lands on the MTA facility in
carefully planned to leave free
for much better planning and predefined locations with
areas so that interconnecting
much more efficient layouts predefined loads. The problem
stairs could be added anywhere
for our tenants, but they was that those predefined
throughout the floor plate.
compounded the challenges points were based on a
As Smilow explains: “Every
facing the engineers,” says completely different design.
engineering decision that we
Andrew Cantor at Related. The previous plans for the site,
made had to keep in mind
“We wanted to have large for which WSP | Parsons
flexibility for tenants.”
openings for future stairs as Brinckerhoff was also the
well as setbacks for double- structural engineer, envisaged
height terraces throughout.” a steel-framed tower with a
They also wanted the building
to be constructed out of
diagrid structure. Now they
had to work out how to land
“OF ALL THE PROJECTS WE’VE DONE
concrete – unusual for a
commercial building in New
a concrete building with a
completely different form in
OVER THE LAST 30 YEARS, THIS
York. “But that was the easy
part,” says Jeffrey Smilow,
exactly the same way.
“Generally speaking, if you
HAS BEEN THE MOST COMPLEX
executive vice president of
building structures at WSP |
compare a typical concrete
office structure to a steel- IN TERMS OF INTEGRATION
Parsons Brinckerhoff in New
York. “The difficult part was
framed building you’re dealing
with roughly twice the load.” WITH INFRASTRUCTURE AND
what lies underground. Of all
the projects we’ve done over
the last 30 years, this has been
explains Smilow. “But we
had to match the steel
building’s loads, and in the
COMPLEXITY BELOW-GRADE”
the most complex in terms of right locations.” JEFFREY SMILOW, WSP | PARSONS BRINCKERHOFF

30 31
32
DESIGNING SKYSCRAPER CITIES ///

AN
FR
I
O CO
O
AN
C NE
LI EN W
M N
IT KE TE OR
AR S M NO R IS LD
EV G
G C O O A T
ST RO HIT NU TH LA RA
EM RU UN EC M ER ND DE
PL O C D TU EN . F M
N AY TIO TU BR R TA RO AR
M K
ER LE
TH EW ED N RE EA E A L
W E Y I A T K N
O IN
CO OR ST OR N T L RO T G D
O
Y
N LD RY KER HE LE HE
ST ’S S L
RU M OF , T IVE IT’S
C OS TH HIS S O
TI T
O FA E IS F
N M
PR O
O US
JE
C
T
33

AN ICON FROM EVERY ANGLE ///

 “DESIGNING A BUILDING IS NEVER EASY.
DESIGNING SKYSCRAPER CITIES ///

AN ICON FROM EVERY ANGLE ///

DESIGNING A SUPER-TALL BUILDING IS
EVEN HARDER. HERE WE WERE FACED WITH
DESIGNING A SUPER-TALL BUILDING IN NEW
YORK CITY WITH THE WORLD WATCHING US”
TJ GOTTESDIENER, SKIDMORE, OWINGS & MERRILL

he goal was always to “create a

T better version of New York,”
says Janno Lieber, president
of World Trade Center Properties.
Lieber is describing Silverstein
Properties’ redevelopment on the former
site of the twin towers in Lower Manhattan, height of 20ft, it begins to gently taper judgement call, says Yoram Elion, senior
an epic 14-year journey that has seen a cast at the corners. By the time it reaches the vice president of building structures at
of thousands overcome technical, logistical uppermost 104th storey, the floor plan WSP | Parsons Brinckerhoff in New York.
and, not least, emotional challenges as is again a square, but slightly smaller “We didn’t want to make new rules that
New Yorkers watched with bated breath. and twisted through 45 degrees. At its would be too conservative and cause a
The 16-acre site will comprise five midpoint, it is a perfect octagon. From dramatic increase in costs. It all had to
towers as well as the National September base to parapet, the building is also the be reasonable but obviously address the
11 Memorial and Museum, but it was the same height as the twin towers – 1,368ft issues.” Gratifyingly, when the new building
completion of One World Trade Center [417m] – before its crowning mast takes codes were finally produced, many of the
in November 2014 that was perhaps the it up to the symbolic height of 1,776ft solutions that the team came up with had
biggest milestone both for the project [541m], reflecting the year of the signing been adopted.
team and the city. This super-tall tower of the Declaration of Independence and The design of One WTC is very
now stands proudly on the skyline, making it the tallest tower in the western different to that of the twin towers. While
filling the void left by the destruction hemisphere. they were held up by external steel
of the original World Trade Center on “We always thought this building should columns, it has a hybrid concrete-and-
11 September 2001 and reinstating an be about simplicity and geometry,” says steel structure. The key to its strength is a
important landmark. What is less obvious architect TJ Gottesdiener, managing massive, extremely strong concrete core.
is the revolutionary impact the project partner at Skidmore, Owings & Merrill This rises all the way to the uppermost
has had on structural engineering itself, (SOM), who led the design team. “We storeys, acting as the building’s primary
redefining the way towers are constructed tried to make it look as clean, strong, support to resist gravitation, wind and
in New York. As the project team worked monumental as possible and that meant seismic loads and impact, as well as housing
to make One WTC the safest ever built, making it look as simple as possible – all means of egress. Steel beams set into
they have developed new technologies although this is far from a simple building.” the concrete core support the floors,
and techniques that have since been One aspect that was always going to enabling vast column-free expanses. The
adopted into the city’s building codes and be complicated was the structural design. core contains two interlinked access stairs
in buildings worldwide. The team had to create a landmark that and a dedicated first-responders’ stair – to
There was never any question that the would restore confidence in tall buildings allow first responders to climb the building
World Trade Center would be replaced. and make people feel safe – but with New quickly in the event of an emergency, while
It may have taken almost seven years Yorkers eager to see results at the site, people escape – a feature that is now
for One WTC’s superstructure to finally the design of One WTC had to proceed standard in New York building codes.
become visible from behind the vast while this thought process was ongoing. The core is made of ultra-high-
hoardings, but the rebuilding plans began “After 9/11, construction just stopped,” strength concrete, at 14,000psi the
almost immediately. “That fateful day says Ahmad Rahimian, director of building strongest ever poured in New York.
the World Trade Center was lost was structures at WSP | Parsons Brinckerhoff “It’s much stronger than any rock you
described by many people as ‘putting in New York, who led the structural design could find,” says Rahimian. This strength
a hole in our heart’,” remembers Steve of One WTC. “The entire engineering also helped to reduce the thickness of
Plate, deputy chief of capital planning and and construction community was trying to the walls, maximising the lettable area,
director of WTC construction at the Port understand what had happened and see while minimising the weight of materials
Authority of New York and New Jersey. what lessons we could learn to make future required. Replacing more than 50% of the
“We needed to replace it as quickly and buildings better. We knew that current cement content with industrial by-products
expeditiously as we could. We needed to building codes would not be sufficient, so further cut the carbon footprint of the
make a statement in the form of a building, we had to design a building for a future building, and more than 95% of the steel in
but driven by people. Now that building code that had not been written yet.” the structure is recycled, contributing to a
has itself become a catalyst for the whole To do this, the team reviewed best LEED Gold environmental rating.
of Lower Manhattan.” practice from around the world and As impressive as the above-ground
One WTC begins from a 200ft square consulted the emergency services and structure is, the tower also has a significant
footprint – exactly the same dimensions the designers of emergency systems. – and challenging – mass below ground,
as the original twin towers. From a But fundamentally, it came down to a which was a Herculean task in itself. The

34 35
DESIGNING SKYSCRAPER CITIES ///

AN ICON FROM EVERY ANGLE ///

“WE NEEDED TO COMMEMORATE WHAT
HAD BEEN HERE AND THE PEOPLE WHO
HAD BEEN LOST, BUT WE ALSO NEEDED TO
CREATE SOMETHING THAT REPRESENTS THE
CHARACTER OF NEW YORK, ITS DYNAMISM
AND ITS HOPES FOR THE FUTURE”
JANNO LIEBER, SILVERSTEIN PROPERTIES

36 37
DESIGNING SKYSCRAPER CITIES ///

AN ICON FROM EVERY ANGLE ///

building’s five underground storeys go coating that creates a constantly changing time, because there’s so much natural light
down 70ft. The masterplan demanded
that the tallest tower be built in the
kaleidoscope. The corners are clad in
laser-finished stainless steel that glints in
flooding in.”
Fittingly, the new World Trade Center
“AFTER 9/11, THERE
north-west corner of the site – but this
meant threading the columns through the
the sunlight. “It reflects the sky and the
buildings around it, and when the light hits
performs a vital civic role too. The
masterplan created by Studio Daniel
WAS CONCERN
tracks of the fully operational train station
underneath. “There is a whole city below
it a certain way you can see right through
it,” says SOM’s Gottesdiener. “Sometimes
Libeskind envisaged a diverse district, with
the National September 11 Memorial &
ABOUT TALL
that extends way beyond the footprint of
the tower,” says Elion. “One World Trade
it glows a bright orange or red. It’s got a
very beautiful quality to it.”
Museum at its heart. More than half of
the site is now given over to public space,
BUILDINGS. THAT
Center has about half-a-million square
feet below grade – that itself is bigger than
many tall buildings.”
Of course, notwithstanding its symbolic
and monumental role, One WTC is a
and the historic streetscape has been
reinstated to make the development much WAS IN OUR MINDS
While this is largely hidden from public
commercial office building. On entering,
workers are immediately faced with the
more permeable. As well as office space,
there are retail and leisure uses to create CONSTANTLY AS
view, back above ground the architects
were responsible for perhaps the most
highly visible façade on the planet.
interior’s most impressive feature: a 50ft-
high atrium. Above that, there are four
levels of mechanical space, before the
a thriving, vibrant community throughout
the day and evening and at weekends
too. A new transportation hub is under
WE LOOKED FOR
Aesthetics were therefore of paramount
importance. Aside from the sheer size of
office floors begin on the 20th storey. After
71 storeys, there are further mechanical
construction, expected to serve 200,000
commuters each day. “We wanted to
WAYS TO REINSTATE
the building, it’s the way that it catches the
light that makes the greatest impression,
floors topped by a three-storey public
observation deck on levels 100-102. “It has
make the World Trade Center a model
of what New York can and should be, and
THAT CONFIDENCE
the luminescence of the structure
somehow lightening its monumental
to function as a very stable, very efficient
environment where people want to come
I think we accomplish that by creating
a more dynamic streetscape with great
IN HIGH-RISE
presence on the skyline. This is thanks to
the floor-to-floor glazing – the exterior of
and work,” says SOM’s Gottesdiener. Key
to this appeal are generous 9ft 6in ceiling
accessibility,” says Lieber. “That’s what
makes it different and special.” CONSTRUCTION”
the building is composed of 1 million ft2 of heights and column-free expanses of up This is already clearly visible in the MIKE MENNELLA,
specially developed glass. This has a very to 45ft from the core to the perimeter, buzz around the site, which has become
high U-value to maintain comfortable as well as the floor-to-floor glazing. “We TISHMAN CONSTRUCTION
a focal point for both New Yorkers and
conditions inside the building and support wanted to allow as much natural light to visitors to the city. “In the last 10 years,
the LEED Gold rating, but it’s also highly penetrate the building as possible. People downtown has evolved tremendously,” says
transparent, with a reflective, mirror-like don’t have to turn on the lights 90% of the Eric Engelhardt, vice president of leasing

for One WTC at the Durst Organization. 2 WTC has been designed by Bjarke users and stakeholders. There are major
“When I started in real estate, downtown Ingels, and will be the second-tallest on retail areas, major transportation areas
always became a bit of a ghost town the site at 1270ft (387m). As well as One and major pathways for trucks, and we’re
when everyone went home. Now it’s WTC, WSP | Parsons Brinckerhoff is the involved in engineering most of these
become a 24/7/365 live-work-play structural engineer for towers 7, 2, 3 and the components.”
neighbourhood. It’s attracting tenants memorial and museum, and conducted Rebuilding the World Trade Center has
from a wide range of industries, from a peer review on tower 4. The WSP | been a vast undertaking, made possible by
financial services to law firms, technology, Parsons Brinckerhoff team also ensured the an unprecedented level of collaboration
advertising and publishing.” overall stability of the enormous ‘bathtub’ and cooperation. “One of the challenges
The towers that those new tenants perimeter walls that encircle the entire site on any project is making sure that you have
will occupy have been designed by a below ground to keep the waters of the the right people on your team and that
prestigious list of international architects. adjacent Hudson River at bay. they can all work together,” says Rahimian
SOM designed not only One WTC but “What you don’t see below ground is at. “But on this project, we all knew it was a
also the first building to complete in 2006, just as massive as what’s above ground,” once-in-a-lifetime opportunity. Bringing
7WTC. November 2013 saw the opening says Jeff Smilow, executive vice president everyone together was easy.”
of 4 WTC, by Pritzker Prize winner of building structures at WSP | Parsons
Fumihiko Maki; Richard Rogers, another Brinckerhoff in New York. “The bathtub
Pritzker Prize winner, has designed is roughly 75ft below grade, and it’s
The National September 11 Memorial 3 WTC, due for completion in 2018; composed of multiple levels with multiple

38 39
DESIGNING SKYSCRAPER CITIES ///

AN ICON FROM EVERY ANGLE ///

O
O

FF O Pict
N
E
IC RL ure
W

BY BIO RAD sy of
IT HAD

IA D cou
L T r te
JU GR E Joe W
D AP CE ool
IT H N he a
H E T
TO STAND TALL

D R ER
UP O
RÉ F
,
WHILE AVOIDING ANY

d
APPEARANCE OF HUBRIS
– A JANUS TASK FOR A
104-STOREY
For more
than a decade,
TOWER the Port
Authority
one of the biggest technological advances
in how towers are built in Manhattan today.
One World Trade of New Set in a public plaza in one of the
Center has occupied York & New most solemn places in the city, One had
centre stage in the global Jersey, itself a to appear dignified and approachable,
imagination. Its structural bi-state agency with while disguising the reality that it is an
challenges were those inherent in a complex governance impenetrable building. Moreover, while
the realisation of any super-tall, but structure. many towers have retail shops on the street
were exacerbated at this location by a The original Twin Towers level, which naturally attract people, One
number of tangible and intangible factors were an urban North Star: one did not have that advantage. Instead, its
that made the project unlike any other. quick glance up and they’d orient you. 186ft-high (56.7m) concrete podium is
One’s massive size, encompassing That too was gone in their wake, leaving covered in sparkling glass panels. Its four
3.1 million ft2 (288,000m2), was determined a gap that was felt viscerally. New Yorkers transparent entrances, oversized to convey
by the need to replace the office space lost wanted their skyline restored – yesterday. hospitality, are ingeniously threaded with a
on September 11. The masterplan placed Consequently, One’s progress was closely flexible cable-net grid that will deflect the
the tower in the most damaged corner of scrutinised, with any delay fanned by the effect of an explosion. Just beyond them
the site. There, below-grade conditions media, creating additional stress for those are secondary concrete walls that are clad
were complicated further by the need to involved. Few understood the sheer size of in dichroic glass, a specialty glass that splits
build over four curving rail lines, which had the substructure, which, at a half-million ft2 the spectrum of light into shimmering
to stay operational during construction, (46,451m2), is larger than many buildings. patterns of colour and makes the entrances
and by constraints imposed by the Architects, contractors and tradespeople – as welcoming as a spring morning.
adjacent structures, with which One shares everyone spoke of the relief they felt when One World Trade Center holds our
foundations and mechanical systems. It the superstructure finally emerged above impossible wish: to have back everyone
had to meet security parameters that had ground on 17 May 2008. The larger site, who was lost on September 11. Of all
never been demanded of any skyscraper, similarly intricate, is a subterranean Rubik’s the challenges that it faced, perhaps the
anywhere. Cube of nine interdependent structures biggest one is exorcising the ghosts of
Infinitely more challenging was One’s with shared foundations, utilities and the structures that it replaced. Spurring
duty as a symbol of all that was lost, mechanical systems. Dozens of designers, innovative design and construction
and reclaimed, on September 11. It contractors and owners had to weigh in on methods, new sustainability standards and
had to provide solace and inspiration every wall and opening. groundbreaking safety measures, One
to millions, most of whom had wildly Given One’s height and slenderness, also provides thousands with a place to
divergent opinions of how that could be WSP | Parsons Brinckerhoff had devised remember, reflect, work, eat and shop. That
accomplished. It had to stand tall, while a concrete-core structure, an effective all those things have been accomplished,
avoiding any appearance of hubris, a solution that would shield internal systems thanks to brilliant solutions and strenuous
Janus task for a 104-storey tower. Some and mitigate shearing forces. However, in effort, qualifies it as a masterpiece.
8 million New Yorkers actively debated New York, because of jurisdictional issues
its design and clamoured to help. The peculiar to its powerful unions, which
project was uniquely bound and slowed govern how steel and concrete crews Judith Dupré is an architectural historian and a New
by this preponderance of good will, and work together, concrete cores were less York Times bestselling author. One World Trade
hindered too by the mandates of dozens frequently used. Ultimately, the unions Center, Biography of the Building will be published
by Little, Brown and Company in April 2016.
of city, state and federal agencies that had agreed that the concrete core could be OneWTCBook.com
jurisdiction over the site, which is owned by constructed ahead of the steel framing –

40 41
42
DESIGNING SKYSCRAPER CITIES ///

THE RISING
CONTINENT

43

THE RISING CONTINENT ///

 200m proposed or under to stand 317m tall. Under the been building towers upwards It may not reach the heights
DESIGNING SKYSCRAPER CITIES ///

THE RISING CONTINENT ///

construction, 33 are in new planning regime, it would of 30 or 35 storeys. Now all of a of other mega-tall locations,
Melbourne. A report by have been limited to 43 storeys, sudden we’re doing many that but Brisbane is still developing

CONTINENT
a Melbourne city council or have to be much thinner or are between 80 and 90 storeys. at a rate, and in a style, that
planner found that its high-rise located on a much larger site. We’re now going from high- would be more familiar to
THE RISING apartments were being built
at four times the maximum
But Sydney, Australia’s
largest city, could easily go
rise to super-rise and that’s
down to a strong presence of
the residents of Asian cities
than most European or
densities permitted in some of mega-tall. WSP | Parsons Asian developers.” American ones. One of its
the world’s most crowded cities, Brinckerhoff has just opened Brisbane’s tallest building biggest projects is Queen’s
such as Hong Kong, New York a new structural engineering used to be the 91m clock tower Wharf, a A$2bn riverside
and Tokyo. office there. The company on its town hall, completed in resort with six residential and
WSP | Parsons Brinckerhoff is already providing building 1930. Its first towers in the 1970s leisure towers, the tallest
has been involved in 22 of systems design on the and 80s were commercial, but 200m, as well as a casino
those new projects, and Greenland Centre, a 235m it was a boom in inner-city and shops. The Destination
Hennessy notes that in contrast tower due to complete in 2017, living that really transformed Brisbane Consortium behind
to previous development, and set to be the city’s highest the skyline. Since 1970, the the scheme includes Hong
A NEW GENERATION OF RESIDENTIAL TOWERS almost all of the new wave of residential building. That city’s population has more Kong-listed developer Far East
Consortium and a subsidiary of
towers are residential. This could be dwarfed by what’s than doubled, from 800,000
IS TRANSFORMING AUSTRALIA’S SKYLINES – AND reflects a massive increase in still to come. “We see Sydney to 1.8 million. “The 200m jewellery giant Chow Tai Fook
alongside Sydney-base Echo
SHOWING HOW CITIES ONCE DESIGNED IN AN city-centre living, he says. At
the turn of the millennium,
as a huge emerging market
for high-rise,” says Hennessy.
tower market has been driven
by residential development,” Entertainments.
AMERICAN IMAGE ARE BEING RESHAPED BY most Melbournians lived in “There’s great potential to build says Gaskin. “Between 1997 Described as a “world city”
houses in the suburbs. “Now towers significantly in excess of and 2007, there were 18 new development, Queen’s Wharf
ASIAN INFLUENCES there’s a trend for people to 300m, 400m, potentially even residential and hotel towers in is intended to encourage
move to the city, and a huge 500m. Sydney is definitely the Brisbane, as well as 11 in Gold international tourism. It aims to
trend for people to live in an next wave. The current market Coast.” celebrate Brisbane’s heritage,
apartment, which wasn’t the is predominantly residential Like Melbourne, a key with 12 football fields of
norm before.” The population but population growth and constraint on the height of public space and 50 bars and
of the central business district urbanisation will also impact on Brisbane’s towers is the nearby restaurants, but it also brings
has grown from just 7,500 in demand for office space.” Brisbane Airport, which also something very new to the city,
n paper, Australia standards of living and a These new market entrants for Americanisation,” he says. 2001 to more than 42,000 The number of cranes on restricts how they are built. and perhaps to Australia – a
O is one of the most stable economy that remained are particularly comfortable “The equivalent for the 21st today, an increase of more
than 550%. This is predicted
a city skyline is often used Above 90 storeys it is difficult glitzy, dense and emphatically
vertical mode of living and
sparsely occupied largely unscathed by the global with high-rise projects, both as century will be Asianisation. to indicate the health of the – but not impossible. One
places on the planet. It’s a recession. developers and buyers of the That’s what we’re experiencing to almost double again by construction market, and the of the city’s biggest projects spending leisure time.
small nation living on a vast resulting product. It is this that in Australia now. It’s a western 2036. Within the next five wider economy. In October is 1 William Street, a 263m Brisbane is traditionally
This is driving a massive
continental landmass, with a is driving the race to the skies continent but it’s being years, there will be 24,000 2015, the Rider Levett Bucknall commercial tower that will be regarded as a pleasant
boom in high-rise development:
population only slightly larger across Australian cities. “China rapidly transformed by Asian more apartments, and 18,000 Crane Index identified 220 on occupied by the Queensland backwater, with little to teach its
“Australia has more skyscrapers
than the New York metro area is way ahead of everyone in influences.” more will be needed to Sydney’s skyline – the highest government. Brookfield peers in Australia or elsewhere.
per person than any other
in an area the size of Europe the scale and the volume of accommodate growth over the recorded since August 2012, Multiplex commissioned But Queen’s Wharf is a prime
country in the world with a Australia’s cities initially
and India combined. high-rise that’s happening right next two decades. and more than any other city an independent consultant example of how styles of
population greater than 5 followed the American
But the reality of the world’s million,” says Mark Hennessy, now,” says Hennessy. “Cities model, defined by low-density All of this is drastically in the world apart from Dubai. to carry out an aeronautical development pioneered in Asia
sixth largest country is that director at WSP | Parsons such as New York were centres sprawl built around the car changing the city’s skyline. If The number of cranes across examination, and successfully could be adapted for western
much of its 7.7 million square Brinckerhoff in Melbourne. of excellence for high-rise, but and self-sustained satellite Melbourne was developed to Australian cities rose by 26% negotiated a three-month cities – creating a hybrid
kilometres is an uninhabitable most of the mega-tall buildings cities. In contrast, Kebel says, the maximum capacity allowed between April and October window to penetrate the urban model that may be
But population growth is not
desert, and its 24 million are in eastern cities.” Asian countries have tended under the current planning 2015 to 539, with more than Brisbane Airport Corporation implemented around the world
the only factor. Much of the
people are clustered in a thin It’s not just Australia’s to concentrate development regime, its massing would 80% on residential projects. limit with the tower cranes for as the century progresses.
development taking place in
green fringe along its southern proximity to Asia that makes around transport nodes and become considerably denser. Over 100 of those cranes the project. Other cities might want to
Australian cities is due to the
coast. Nearly two-thirds of it a pioneer over the US or collective amenities. Now cities According to a projection were in Brisbane, capital of the watch closely.
arrival of deep-pocketed Asian
Australians live in its five largest Europe, says Igor Kebel, design such as Melbourne and Sydney by XO Projects, there could state of Queensland, which
investors and developers.
cities, and these are currently director at architect Elenberg are shifting rapidly from a be an extra 170 towers, four also has ambitious building
According to property firm
the scene of some of the Fraser and co-founder of XO horizontal plane to a vertical million square metres of plans. Australia’s third most
Knight Frank, Asian investors
world’s densest development. Projects. “Australian cities are one, as people reject long gross floor area and nearly populous state is home to
have spent more than A$22bn
younger, a lot less established commutes and congestion in 21,000 apartments, and the 4.5 million people, and six of
While the habitable
portion of the country is, if
anything, shrinking due to
on core Australian property
over the last two years, making
it the third-largest investment
and a lot more exposed than
old world countries. Some
favour of more compact living
spaces with essential amenities
CBD population could reach
140,000.
its tallest buildings. Brisbane
already has more than 50
“AUSTRALIA HAS MORE
climate change, its population
growth is far outstripping
destination behind the US and
UK. Sydney and Melbourne
things are only possible here. If
you want to see what the new
on their doorsteps.
Melbourne is Australia’s
Melbourne’s potential as
a super-high-rise city to rival
towers over 100m in height,
topped by the 249m Infinity.
SKYSCRAPERS PER PERSON
most comparable countries.
Between 2011 and 2015,
were the primary targets,
but as the market heats up,
urban world is going to be like,
you have to go to Australia.”
fastest growing city, and
arguably the one experiencing
Hong Kong or Shanghai is,
however, limited. Building
Surfer magnet Gold Coast is
the site of the country’s tallest THAN ANY OTHER COUNTRY IN
Australia’s population grew
by an average of 1.6% a year,
investors are now looking
further afield to Brisbane,
Kebel believes that the
densification taking place in
the greatest Asianisation
right now. Its double skyline
heights are constrained
around the 300m mark by
building to date, the 323m-high
Q1, a residential tower THE WORLD WITH A POPULATION
compared to increases well
below 1% for much of Europe
Perth, Canberra and Adelaide.
Foreign buyers accounted for
Australian cities is a foretaste
of what we can expect
– running along the east and
west banks of the Yarra river
flight paths, and Victoria’s new
state government is imposing
much stricter city planning
completed in 2005.
“Asian money is certainly a GREATER THAN 5 MILLION”
and the United States. A between half and two-thirds elsewhere as the century – already boasts 32 buildings big driver in the Queensland
rules on development density. MARK HENNESSY,
large proportion of this is from of sales of higher-density progresses. “During the higher than 150m. It’s also construction economy,” says
net migration. Both talent residential sites in Sydney, 20th century, the world was home to the lion’s share of Construction has just begun WSP | PARSONS BRINCKERHOFF.
John Gaskin, Brisbane-based
and investment are pouring Melbourne, Brisbane and Perth developed by globalisation, Australia’s future towers. on Australia 108, a 100-storey non-executive director at
into Australia, lured by high in the year to August 2015. which is an alternative term Of 49 buildings over apartment building that is set Brookfield Multiplex. “We’ve

44 45
DESIGNING SKYSCRAPER CITIES ///

THE RISING CONTINENT ///

PREMIER TOWER, “IT’S IN A PRIME LOCATION, AND
IT’S GOT A VERY DISTINCTIVE
MELBOURNE 249m VARIABLE FORM”
PETER HINDMARCH,
One of Melbourne’s tallest extensively in a wind tunnel.” WSP | PARSONS BRINCKERHOFF
and most prestigious There is provision for a tuned
developments, this project is mass liquid damper at the top
best known for its inspiration: of the building, to further slow
the Beyoncé video ‘Ghost’, the movement, and this will
which features writhing also double as the fire tank.
dancers tightly shrouded Melbourne’s construction
in fabric. industry is predisposed to
The result is an elegant, concrete. This is always
amorphic form, designed by post-tensioned, reducing
Elenberg Fraser, that sits on an floor-to-floor heights and
island site opposite the city’s adding strength – spans
main train terminal. Expected of 8m x 8m are typical for
to rise to 78 storeys, it will apartments. At Premier Tower,
include no less than 1 million ft2 the flat plates are 200mm
of space, comprising 780 one- bonded post-tensioned slabs,
and two-bedroom apartments allowing floor-to-floor heights
and 180 hotel suites, as well as a of 3m, with ceiling heights of
range of leisure facilities. about 2.7m. The shape of the
Recreating those sinuous floorplates varies throughout
curves in glass, concrete and the building, so walking
steel was no mean feat for the columns were used to transfer
structural engineer, especially loads to different parts of
while minimising intrusion the structure. At the deepest
on the usable floor area and curves, the slab edge on the
internal layouts. line of the corner columns
varies by 5m. The internal edge
“It’s in a prime location, of the columns remains in the
and it’s got a very distinctive same place, while the external is
variable form,” says Peter stepped to support the longer
Hindmarch, director at cantilevers. The result is that
WSP | Parsons Brinckerhoff the corner columns change in
in Melbourne. section from 800 x 800mm to
Premier Tower is also a 3,950mm x 300mm in six steps.
slender structure – the ratio of Along the shallower curves,
its height to structural width is the internal columns walk in
8.3 from the ground up, but a and out to fit around internal
much more challenging 10.8 layouts and doorways.
above the podium. To maintain Below ground, there are
the building’s movement in four basement levels with car
the wind within acceptable parking. These are broader
levels, mega-columns on the than the tower, so the columns
façade maximise the width of transition horizontally as
the stabilising structure, and they reach the podium, by
these are tied to the core by approximately 4.5m over a
two- or three-storey outriggers height of 18m, or six storeys. “If
concealed in party walls, and we’d kept the column locations
secondary outriggers at the the same as in the tower above,
mid-height plant floor. “The they would have clashed with
mega columns are sized to the aisle in the car park,” says
carry both gravity and wind Hindmarch. “By transitioning
loads,” explains Hindmarch. them, we can locate them
“The wind load forces can be between parking bays instead.
equal to the weight supported This also increases lateral
by the column. Controlling stiffness, and it meant we didn’t
the acceleration is the most use any transfer beams, which
important thing for a residential reduced structural height and
building, so we tested it construction time and cost.” Images courtesy of Elenberg Fraser

46 47
 VERTICAL
DESIGNING SKYSCRAPER CITIES ///

THE VERTICAL SOCIETY ///

IN THE FACE OF RISING URBAN
POPULATIONS AND RAPIDLY CHANGING
LIFESTYLES, THE CHALLENGE IS NOT
SIMPLY TO BUILD HIGH-RISE
STRUCTURES. WE NEED TO BUILD
HIGH-RISE COMMUNITIES

THE SOCIETY

“THE NEW HIGH-PERFORMANCE

BUILDING IS NOT JUST A
TECHNOLOGICAL MARVEL, IT’S
ALSO A CULTURAL TOUCHSTONE,
IT’S A BRAND BEACON, IT’S AN
INNOVATION ACCELERATOR”
PETER WEINGARTEN, GENSLER

48 49
 a famous MIT study that began in the vertical form. Woods Bagot is designing dominant group in western Europe and
DESIGNING SKYSCRAPER CITIES ///

THE VERTICAL SOCIETY ///

1970s: “If you work on the same floor a ‘vertical campus’ for a client in Jakarta, North America, and this will be the fastest-
as someone, you have a 95% chance of which features a broad range of amenities growing profile worldwide between 2014
running into them in the course of your in the base and a series of interconnecting and 2030.
day. We know that face-to-face interaction atria spiralling down the building to bring The majority of these households
is the key driver behind innovation so people together (see page 54). are to be found in cities. The biggest
that’s a very important statistic.” If people There will also be a greater range of occupier groups for the high-rise buildings
are on different floors, this drops to 5%, amenities in the high-rise residential of the future will be young singles or
and if they’re in different buildings, it’s just buildings of the future. This is partly down couples, successful business people
0.02%. “You’re lucky if you see them at to density – there simply won’t be room without children, and retirees, says Igor
all as you’re traversing the asphalt of the to build duplicate spaces for everyone. Kebel, design director of Elenberg Fraser,
parking lot to get to your car.” Where there But it’s also down to a combination of which has a number of tower projects in
are no constraints on space, companies demographic and social trends, which the booming Melbourne market. “The
would ideally want floorplates to be as are causing household sizes to shrink. world is turning around,” he says. “That
big as possible – Apple’s new Cupertino Millennials are settling down later, fertility makes the demographics very specific
campus will have circular floorplates with rates are declining, divorce rates are and sets different parameters for design.
a circumference of more than a mile, with climbing, and older people want to remain It allows us to develop new products
approximately 840,000sqft of space on independent for as long as possible as for new lifestyles.” His use of the word
Design for a sky street by Woods Bagot
each of its four floors – but recent studies life expectancy rises. According to data “product” is deliberate, he adds. “I use
show that there is a diminishing return after from Euromonitor, one- and two-person the analogy of a smartphone, where there
a certain point. households will see the greatest growth are many communal services that allow
Such expansiveness clearly isn’t possible globally between 1980 and 2020 – both you to customise your social space and
he future is not just taller. walkable and well-connected. Millennials
T It’s also more crowded, more
diverse, more collective – and
“CHANGING are now luring employers back into cities
too. During the 20th century, many firms
in the dense grid of a city. But designers
are finding other ways to create the
interactivity of a horizontal campus in
up by 183%, compared to an increase
of just 91.7% for couples with children.
Single-person households are already the
social preferences.”

more solitary too.

Anticipating the future has always been
DEMOGRAPHICS ARE left downtown areas in favour of suburban
campuses – a paper for the National
a challenge for designers, developers and
planners, but high-rise buildings bring
SETTING DIFFERENT Bureau of Economic Research in the
US found that the proportion of jobs in
these questions into sharp relief. The sheer
scale of super and mega-tall towers is a
PARAMETERS AND American city centres fell from 63% in
1960 to just 16% by 1996. This trend has “IF YOU WORK ON THE SAME
completely new typology for humankind –
people have never attempted to live, work ALLOWING US TO begun to reverse – according to the
Brookings Institution, the number of city FLOOR AS SOMEONE, YOU
or play together at such heights, in such
numbers. And the energy and expense DEVELOP NEW centre jobs grew steadily by 0.5% a year
between 2007 and 2011, compared to an
annual loss of 0.1% on the peripheries.
HAVE A 95% CHANCE OF
involved in demolishing tall towers means
that they will have much greater longevity,
and will have to accommodate much
PRODUCTS FOR Not-for-profit Smart Growth America
carried out a survey of 500 companies
RUNNING INTO THEM IN
more change than conventional buildings
over their lifespan. The towers we build
NEW LIFESTYLES” who had moved back into cities, and found
that by far the biggest reason was to attract
THE COURSE OF YOUR DAY.
today may still be standing in cities that are
almost unrecognisable. This means they
IGOR KEBEL, ELENBERG FRASER and retain talent: being located in a vibrant,
amenity-rich neighbourhood with good
WE KNOW THAT FACE-TO-
need to be designed with one eye on the
future, and enough flexibility to adapt to
Weingarten has noticed that millennials
have very different priorities to the post-
public transport links was seen as a
key differentiator. FACE INTERACTION IS THE KEY
whatever else comes their way.
One of the most significant trends
war babyboomers now reaching retirement
age: “Boomers wanted to own stuff.
Millennial culture is characterised by
a blurring of the lines between work DRIVER BEHIND INNOVATION”
already influencing designers is the and leisure, which is inevitably reshaping PETER WEINGARTEN, GENSLER
They were encouraged to value domain.
coming-of-age of the ‘millennial’ corporate structures too. Companies
What’s my status at work, where’s my
generation, born towards the end of the are adopting less hierarchical models,
house, do I own a car? Now it’s not about
20th century. By 2020, millennials will says Weingarten, and workplaces have
the ownership of things, it’s about the
comprise half of the global workforce, and to adapt. “Employees are no longer just
experience of things.” This is partly through
they already outnumber older colleagues workers, they’re entrepreneurs, and there’s
necessity, as recession has diminished the
in the US. much more of a sense of community-
prospects of home ownership for many.
based coaching and mentoring in the
Millennials are characterised as But it’s also because digital technology
workplace. We see this all the time when
footloose city-dwellers, overturning many makes it easier than ever before to
we sit down with our Fortune 500 clients
decades of suburbanisation. They are temporarily acquire things people
who are looking to go into these mega-
also ‘digital natives’ who have grown up previously aspired to own. ‘Collaborative
towers and super-tall buildings. They
with the internet, mobile phones and consumption’ apps such as Airbnb and
leverage mobility and technology, but want
social media, and it is this that will have Uber give smartphone users instant access
to see more true connectivity than just
the furthest-reaching consequences, says to homes and cars anywhere in the world
what is offered by technological solutions,
Peter Weingarten, principal at Gensler in with just a few swipes and taps.
so the new high-performance building is
Oakland, California. “It’s not about age, With a world of instant information not just a technological marvel, it’s also a
it’s about the experiences you have that in the palm of their hands, millennials cultural touchstone, it’s a brand beacon, it’s
influence who you become as a human also demand more from the spaces they an innovation accelerator.”
being. Clearly the context of digital occupy physically. They prize quality of life
technology has had a profound impact The quest for innovation is also driving
and easy access to shops, entertainment
on how people perceive experience.” higher occupancy levels and much bigger
and places to spend time with friends,
floorplates, says Weingarten. He quotes
and prefer to live in urban areas that are

50 51
 Lotte Tower, Seoul These are not necessarily public spaces collective spaces, for the good of society formula, it’s mandated by the city,” explains
DESIGNING SKYSCRAPER CITIES ///

THE VERTICAL SOCIETY ///

Image courtesy of KPF
but hybrids, funded privately and used and our own sanity. “When we see this kind von Klemperer. “But the point is that it is
“THE POINT IS THAT collectively. Apartments themselves will
have small kitchens, but residents would
of density, we immediately think of the
need for something more than occupied
possible to provide truly public space of a
civic sort within the complex section of a
IT IS POSSIBLE TO have on-demand access to a larger one
if they were throwing a party or having
space, sold space, work space, living space
– something more public or collective that
high-rise building.”
A mix of facilities is important for
PROVIDE TRULY family to visit. “It’s hotel amenities in a
residential package, so people live in a
could animate such a mass of habitation
or work,” says James von Klemperer,
keeping highly skilled workers in cities
as they grow older, adds Steve Burrows,
PUBLIC SPACE OF hotel-like environment and pay an extra
fee for that. Residents will have their own
president and design principal of Kohn
Pedersen Fox Associates. The ideal is
executive vice president at WSP | Parsons
Brinckerhoff in San Francisco. “We need
A CIVIC SORT cinemas, meeting spaces, dining rooms,
living rooms, lounges, spas – you name it.
With the ageing population, you would
to infuse large structures with a series of
places where people could wander or
congregate, just as they would in a city
to consider all the things that make a living
city,” he says. “Sport for example – are

WITHIN THE not go wrong with a karaoke room.” Kebel

typically allows between 2.5-4m2 additional
streetscape, “to create a very complex,
inviting and interesting set of sectional
stadiums civic buildings? Should they be
downtown? And how do hospitals and
schools fit into vertical cities? In order
COMPLEX SECTION amenity space for each apartment: “Clients
will pay for it because sales are higher.”
experiences”.
In mega-projects, architects can create
to capture families, something’s got to
change. How are our cities going to
OF A HIGH-RISE The other reason why these spaces
will be so important is because the future
‘vertical cities’ by taking advantage of the
gaps between different uses to create
become liveable for people throughout
their entire life cycle?”
BUILDING” is potentially a much lonelier place, says
David Symons, director of sustainability
gathering places. KPF’s JR Central Towers
project In Nagoya put almost 5 million ft2
One of the phrases von Klemperer
uses is “building community” – a concept
JAMES VON KLEMPERER, KPF at WSP | Parsons Brinckerhoff in the UK, of retail, office, hotel and public space that will become more and more relevant
who is leading its ‘Future Ready’ initiative. stacked on top of a bullet-train station – as the life of towers extends throughout
“Advances in technology mean you could it holds a Guinness World Record as the the day and night and people spend
potentially work from home and have your largest station building in the world. There increasing amounts of time in high-rise
shopping delivered to you – there might is a range of public and outdoor spaces developments. This is something that
be a certain group of people who live on throughout the building, as well as Sky Woods Bagot has also been considering
their own and never leave the house. That’s Street – a huge concourse on the 15th in the context of the vertical campus.
not necessarily a good thing. Interaction floor of the podium joining the two towers, “You have to think about what makes a
then becomes really important – people which offers panoramic views to anyone strong community,” says global workplace
will value it much more in the future.” who takes the elevator from the station. leader Steve Hargis. “It’s not just an office
Buildings will need to be designed to “Part of the challenge is to show the – you have to supplement that with all
compensate for more solitary lifestyles, vertical transportation in a very visible way the services and experiences that people
he says. “In many tall apartment buildings, at the front to bring people up naturally,” need.” In the design of these buildings,
there is scant interaction with other says von Klemperer, “so that they feel not he thinks that the role of architecture
residents – you just go up in the lift, come compelled but interested in achieving crosses over into urban planning. “We
out into your stairwell and go into your these higher levels where they could do are in the middle of an unprecedented
house. That’s not encouraging interaction things not necessarily programmed by migration to urban centres, so it’s up to us
or providing a design that is good for their rental agreements but by some sort as a profession to build something that is
interaction.” of public street.” sustainable, where people want to be, that
Symons cites the example from a At Hysan Place in Hong Kong, another supports the kind of community life that
book by Charles Montgomery, principal mixed-use scheme of 716,000ft2, the we’re all looking for.”
at urban laboratory Happy City, of a building is conceived as a series of shifting “When you think about high-rise office
wealthy Vancouverite who swapped forms to create a series of vertical gardens development over the last 20 or 30 years,
the panoramic views from his fabulous over the height of the project. Here too, a lot of the metrics are consistent,” adds
but lonely apartment for a cramped the escalators are clearly expressed on the Woods Bagot principal John Britton,
townhouse where he could get to know his outside of the building, zigzagging up the based in San Francisco. “Critical factors
neighbours. The townhouse neighbours façade and “beckoning to the crowds to include floorplate efficiency, tightness
were not inherently more sociable than the find retail space at the upper levels”, says of the core, effectiveness of elevatoring,
apartment dwellers, but they each had a von Klemperer. appropriateness of lease spans. Now
porch overlooking a shared garden, which “It’s finding opportunities to make there’s this increasing focus on the human
provided regular opportunities for easy spaces. The melange of tunnels and aspect of a development – a chance to
contact with other people. This reflects the walkways that go through this project look at buildings through the lens of an
‘soft edges’ promoted by Danish urbanist becomes a sort of jungle gym for a series occupant, at the quality of life that the
Jan Gehl in his seminal 1971 study, Life of truly public spaces through this mixing building can help them to achieve. For us,
Between Buildings. He argued that houses chamber of retail, and ends up in pockets that’s a new challenge and a new way to
should have semi-private front gardens to of space above that are semi-public. look at buildings.”
bring residents outdoors to engage with So there’s a pallet of interior spaces that
neighbours and passers-by. For maximum animate this sectionally articulated piece
interaction, they should be small enough of the city.”
to allow conversation but large enough so It’s not easy to create genuinely public
there is space to retreat – Gehl’s research spaces in mega-projects – but it can be
showed that the optimal size was 10ft 6in. done. KPF’s design for the 555m Lotte
Translating these lessons from horizontal World Tower in Seoul includes a cultural
spaces to vertical ones will be the next centre, kids’ park, jazz bar and aquarium as
great urban design challenge. When cities well as a 2,000-seat concert hall, which will
are denser and buildings much larger, high- be the home of the National Orchestra
rise developments will need to offer more of Korea. “It’s not a piece of commercial

52 53
 saturation. So how do you become the go-
“THE IDEA IS TO GET
DESIGNING SKYSCRAPER CITIES ///

THE VERTICAL SOCIETY ///

to building? What sets your development
apart from the next? It’s a future-proofing
discussion.”
The vertical campus may even offer
THIS SPIRALLING
an advantage over the horizontal version,
suggests Hargis, especially where it
CONNECTIVITY, MORE
includes apartments too. He has watched
Silicon Valley campuses grow from a few
COLLABORATIVE
buildings to dozens, sometimes hundreds.
“It was used to be about being compact SPACE, BREAKOUT
and secure, and controlling your future –
you could expand across the street, or you SPACE, DYNAMIC
could contract,” he says. As companies
have grown, distances between buildings
become unwieldy and circulation is
SPACE, MORE
increasingly about bikes, buses and cars.
The distances between spaces on
LIGHT AND AIR
a vertical campus are significantly shorter
in comparison.
THROUGHOUT
VERTICAL

“The proximity of residential really

changes the game,” says Hargis. “That’s
THE BUILDING”
something that the corporate world is really JOHN BRITTON,
struggling with on a horizontal campus. In a WOODS BAGOT
denser urban environment, it’s much easier
to get that work-live-learn-play model,
which is one of the key components of
making a campus work.”

THE
CAMPUS
ACROSS ASIA, campus mentality,” says John Britton,
principal at Woods Bagot, based in San
elevator.” The result is a series of three-
storey atria spinning down through the
about 40,000m2. Between each tier,
there are two mechanical floors, and two
INNOVATIVE TOWER Francisco. “They asked us to replicate the building, rotating from the common core sky lobby transfer floors. “There is the
qualities of a horizontal campus. They to balance the structural loads. Spaces potential to market a tier as a package
DESIGNS ARE said, ‘What would it take to create a are connected by staircases to encourage to class A international corporate clients
INCREASING THE workplace that would be unique for us?’ ” free movement between floors, and and allow them to tailor it to their uses,”
The scheme is on the city’s main filled with natural light. “We’ve tried to says Britton. “So if a company wanted to
CONNECTIVITY thoroughfare and currently comprises incorporate active uses, we want them to take a very campus-like approach, with
be very active, very visible areas. We’ve
BETWEEN FLOORS three buildings of 16, 22 and 48 storeys,
got meeting pods and work areas on the
breakout rooms, cafeteria, small theatres,
they could capitalise on those interstitial
linked by a multi-storey podium. “There
TO MEET THE VARIED needs to be a fabric that links the buildings, ground floor of the atria, and we want spaces. There’s close to 6,000m2 available
so the podium provides all those amenities people to come down and collect in these on each set of transfer floors, so there’s an
NEEDS OF MODERN that you would see across a horizontal various spaces.” opportunity in how you develop them.”
BUSINESS campus – everything from gathering The PT Telkom tower is a tailor-made “The client was very interested in the
spaces, to food and beverage, theatres, response to one organisation’s needs. application of atria to the project. There
medical clinics and gyms. The horizontal But Asian developers are also leaping on are a lot of different strategies for how
While 20th-century workplace trends spine connects the three buildings, but it’s vertical campus ideas to set their schemes you do that, and it does not have to apply
were led by US companies, the high-rise, also the cultural connection.” When the apart from the competition. Woods in every tier if the market demands larger
high-tech offices of the future are being distribution of amenities is mapped out on Bagot is also designing the speculative floorplates. But the idea is to get this
pioneered in Asia. Architect Woods paper, the vertical campus doesn’t look too Tradewinds Square development in Kuala spiralling connectivity, more collaborative
Bagot has designed a ‘vertical campus’ different to the horizontal one. Lumpur, which will comprise 500,000m2 space, breakout space, dynamic space,
in Jakarta for PT Telkom, Indonesia’s What really sets a vertical campus apart and have a population of 18,000. There will more light and air throughout the building.”
largest telecommunications company. from a conventional office tower is the be a 625m office tower and a 325m mixed- The campus approach may mean
When completed, it will bring together connectivity between different floors. “We use tower of residential and serviced sacrificing office space, but it also helps
8,000 staff in 25 corporate entities from did a survey with the client to find out apartments, again linked by a podium with you to stand out in a crowded market, says
buildings all over the city, partly in order the maximum number of floors people 100,000m2 of retail and amenity space. Steve Hargis, global workplace leader at
to get them talking to each other. “They would be willing to walk, and it turned out The design envisages the office building Woods Bagot. “There’s quite a bit going
were very interested in having a corporate to be about three before they got into an as five 15-storey tiers, each one comprising on in KL and there is potential for market

54 55
 THE WAVE OF SUPER-SLENDER RESIDENTIAL to withstand wind and seismic
DESIGNING SKYSCRAPER CITIES ///

RETURN TO SLENDER ///

RETURN TO
forces – but the structural
TOWERS RISING OVER MANHATTAN COMBINES components must also be
kept as unobtrusive as possible
THE LATEST STRUCTURAL GYMNASTICS to maximise usable space
WITH THE GRACE OF NEW YORK’S CLASSIC and uninterrupted views. A
building’s core is an important
ART DECO SKYSCRAPERS source of stiffness but this
can be proportionally smaller
in a residential tower than a
commercial one. Conversely,
the higher a tower and the
ou might think WSP | Parsons Brinckerhoff more people living there, the
Y that 111 West 57th in New York, the structural greater the elevator capacity
needs to be, and the amount
Street is an extremely engineer on the project. “It’s
thin building. going to be a world record. of mechanical, electrical

SLENDER But 111 West 57th Street is

undeniably slender in high-
rise terms – a super-slender
building certainly, and perhaps
even a ‘mega-slender’ one. In
the global race to build tall, it’s
no longer all about height. The
other number that everyone
wants to know is the aspect
But we are working on others
that are going to be even
more slender.”
The logic of slender
buildings is to derive the
greatest possible value
from expensive, constrained
city-centre plots. So it’s no
surprise that the super-slender
and plumbing infrastructure
increases. “All of this can swell
the core and encroach on living
space,” says Fatih Yalniz, vice
president of building structures
at WSP | Parsons Brinckerhoff
in New York, who carried out
analysis to establish the most
effective frame for 111 West
57th Street.
ratio: the relationship between revolution began in New
a building’s height and its York, a pioneering skyscraper Hundreds of metres above
width. 111 West 57th is one of city with some of the most the ground, wind flows are
a new breed of towers that are sought-after real estate on completely different – more
pushing that ratio to previously the planet and a clamouring akin to what an aeroplane
impossible levels. global customer base. “There’s would experience. In managing
something unique about living the building’s response, their
New York building codes goal is not to eliminate all
consider a building to be in Midtown and having that
perfect view,” says Koster. movement, but to control the
slender when its height is more pace of acceleration. Marcus
than seven times its width at “Everyone understands the
beauty and value of being able likens it to being in a car:
the narrowest point. But the passengers only sense the
recent crop of luxury residential to build something like this in
this location.” movement when accelerating
towers in the city’s Midtown go or braking, not when travelling
far beyond this. In 2014, One57 Where these towers differ at a constant speed. “It’s
raised eyebrows with an aspect from previous generations is impossible to stop a building
ratio of 8:1, becoming the that they are not commercial from moving, but we can
tallest residential building in the but residential – typically, each control that movement so the
city at 1,005ft (306m). It has floor comprises a single luxury majority of people will not feel
been quickly overtaken in both apartment. This only adds to it.” As residential buildings,
senses by 432 Park Avenue, its the challenge for the structural these towers must meet more
1,396ft (426m) height 15 times engineer. High-rise engineering stringent standards than
the width of its base. There are is a very specialised discipline, offices: there is no question of
more under construction: 56 and many of the technologies evacuating an apartment tower
Leonard Street (10.5:1), 30 Park used in conventional low-rise in the event of a hurricane, and
Place (12:1) and 53W53 (13:1). construction would be too people need to feel safe and
But 111 West 57th Street beats heavy, inefficient and expensive comfortable in their homes no
them all with a staggering if applied to tall buildings. But matter the weather. “A person
aspect ratio of 24:1. Rising from super-slender changes the coming home to the 50th floor
a plot of just 80ft by 590ft, it is game yet again. There is no does not expect to move in
1,435ft tall (437.5m). theoretical limit to how tall a the wind,” he points out.
“It’s almost three times more building can be, but the taller “Slender towers have such a
slender than what used to be you go, the stiffer and stronger small plan area, we have to
considered a slender building,” the structure needs to be. A mobilise everything possible
says Silvian Marcus, director of skinny building will also need to to achieve that.”
building structures at be stronger than a broad one

“IT’S GOING TO BE A WORLD RECORD. BUT WE ARE WORKING ON

111 West 57th Street, New York
OTHERS THAT ARE GOING TO BE EVEN MORE SLENDER”
Image couretsy of JDS SILVIAN MARCUS, WSP | PARSONS BRINCKERHOFF

56 57
DESIGNING SKYSCRAPER CITIES ///

DESIGNING SKYSCRAPER CITIES ///

“THERE’S SOMETHING UNIQUE
ABOUT LIVING IN MIDTOWN AND
HAVING THAT PERFECT VIEW”
SIMON KOSTER, JDS DEVELOPMENT GROUP

111 West 57th Street, New York

Image couretsy of JDS

58 59
 As in the last golden age of either solid, in the case of a Commission to relocate the This is what they have tried unique shapes repeating across says Getman. The bronze 57th Street. “We don’t want to these are exactly the sorts
DESIGNING SKYSCRAPER CITIES ///

RETURN TO SLENDER ///

New York skyscrapers, every tuned mass damper, or liquid, tower further back on the to recreate with the material the façade in an undulating has also been left unfinished see cracks on plaster, or glass, of thing that prospective
developer wants to set their as with a slosh damper. As the site. It’s really set back so palette of 111 West 57th Street. pattern, which will create a so that it will age gracefully or leaky windows because the residents want to know. “Future
building apart with an iconic building moves, the weight you don’t really perceive it “These amazing shear walls pattern of shadows from a with the building. building is moving too much.” homeowners ask questions
design as they compete to moves too but more slowly – from the street, and instead gave us some solidity to play distance. The filigree adds a Enormous care has been The ultimate success for about where they’re going
attract the attention of a very thus slowing the acceleration of we’re creating a very open with, so we had the opportunity level of detail that only will be taken over the appearance of the engineer is when their art to live,” says Koster. “We’re
discerning global client base. the tower. atrium that frees the landmark to do another style that revealed as you get closer, as 111 West 57th Street, and the goes unnoticed: the goal is for having conversations about
“Every building is unique and building to be read in its wasn’t just glass,” she explains. a homage to the rich façades whole design team has a role to building occupants to live in the structural damper, shear
For 111 West 57th Street,
it needs a unique structural historic context.” This lower The building is very finely of New York’s classic Art Deco play in ensuring the integrity of total comfort, unperturbed by walls, the overall stiffness of
WSP | Parsons Brinckerhoff
concept,” says Hezi Mena, section of the scheme will tapered – Getman describes buildings. “We’ve been working these finishes over the life of any movement. But as people the building, movement, sway,
has achieved the necessary
senior vice president of offer shared recreation spaces, is as “feathered” rather than hard to find that balance the building. “The structure are living greater distances slenderness … All these things
strength with two shear walls
building structures at WSP | a lobby and high-end retail. stepped back – which gives it between the ‘handedness’ that itself will be able to flex, but above the ground, there is an are just starting to become part
running the height of the
Parsons Brinckerhoff in New Above, there will be 77 floors of a human scale despite its giant you find in the old buildings other elements are not as increasing awareness of the of the residential buyer’s lexicon
east and west elevations of
York. “There is no set formula.” luxurious apartments. size. Each of these small steps – so the terracotta has five flexible unless we coordinate systems and the strategies that in New York.”
the building. This leaves the
is marked by a solid terracotta different glazes to give it a bit their design and engineering,” make high-rise living possible.
There are however some others completely clear, so that When SHoP looked
pilaster, with a curving bronze more texture – but at the same says Cynthia Liu, senior vice Koster says that while office
proven strategies, which residents can enjoy unimpeded around at the city’s best-loved
filigree stretching between the time, it’s developed using state- president at WSP | Parsons occupiers rarely concern
Mena and his colleagues vistas of Central Park to buildings, a common theme
pilasters to climb the building. of-the-art technology to track Brinckerhoff in New York and themselves about the structural
have refined as they have the north and Midtown and was “their shadow, their depth,
The pilasters are made from 23 the pattern across the façade,” project manager for 111 West systems of their workplaces,
achieved increasingly slender downtown Manhattan their solidity”, says Getman.
designs. The first step is to to the south. There is also a
stiffen the structure. For this tuned mass damper at the top
reason, super-slender towers of the building, concealed by
are invariably concrete rather
than steel. Using concrete for
the core of the building and
the lightweight steel structure
that completes its delicate
tapering form.
“SUPER-SLENDER IS
connecting shear walls enables
the engineers to minimise
Dana Getman, associate
principal at SHoP Architects,
A RETURN TO THE
structural elements within the
apartments themselves, giving
the lead designer, argues that
far from being a new typology
PROPORTIONS OF CLASSIC
the occupants maximum
flexibility on layouts and
for New York, super-slender
is just a return to its classic era
NEW YORK SKYSCRAPERS.
preserving those all-important
views.
of skyscrapers. “That’s what’s
interesting about this new
WE HAVE AN OPPORTUNITY
But strength alone is not
enough. “Brute force does not
generation of towers,” she
says. “Pre-war, before air- TO LOOK BACK TO HISTORIC
work here,” says Jeff Smilow,
executive vice president of
conditioning, buildings tended
to be thinner to get people BUILDINGS AND WHAT
building structures at WSP |
Parsons Brinckerhoff in New
York. “We have fewer
closer to light and air. In these
new buildings, because they’re
residential, light and air again
MAKES THOSE SO SPECIAL”
engineering opportunities so becomes an issue and we have DANA GETMAN, SHoP ASSOCIATES
we have to be more innovative. an opportunity to look back
We have to work with the wind to historic buildings and what
instead of fighting it. The goal makes those so special.”
is to find out what works, what With this in mind, SHoP
shape responds best to the has approached 111 West 57th
wind and reduces the Street with the ambition of
acceleration, not just to add creating a classic Manhattan
structure unnecessarily.” skyscraper. In fact, while the
One option is to adjust the building’s super-slender form
shape of the building to make it may look startlingly new, it is
more aerodynamic, introducing itself a heritage project. As
openings to allow the wind to well as the construction of the
pass through or adding curves tower, the scheme involves the
at critical locations along the complete restoration of the
façade to minimise the ‘vortex 1923 Steinway building, an Art
shedding’ response which Deco landmark for the city.
causes high acceleration. The tower has been carefully
WSP | Parsons Brinckerhoff located in deference to its
works closely with architects to historic neighbour. “We could
refine the shape of a building, have built a tower directly
using wind tunnel analysis. adjacent to the Steinway
The engineers can also building without city approval,
reduce the acceleration of the but it wasn’t what was right
movement by using a damper, for the landmark and it wasn’t
similar to the shock absorbers right for the tower,” explains
in a car. This is a heavy weight Getman. “So we worked with
111 West 57th Street, New York
placed high up in the building, the Landmarks Preservation CGI interior of 432 Park Avenue, New York
Image couretsy of JDS

60 61
 ARK
2 P E
SUPER-LUXURY
DESIGNING SKYSCRAPER CITIES ///

RETURN TO SLENDER ///

43 ENU 15:1
SERVICES AT
HEIGHT

425 M
BY GARY POMERANTZ,
SUPER-TALL EXECUTIVE VICE PRESIDENT

AV
HEIGHTS
ASPECT RATIO OF BUILDING SYSTEMS,
WSP | PARSONS BRINCKERHOFF

Apart from its extreme The mechanical or ‘drum’

slenderness, it is perhaps the floors also play a crucial role
simplicity of 432 Park Avenue’s in making the building more
structure that has already thermodynamic. Early wind-
made it a favourite landmark tunnel testing showed that the
on the skyline. structure was suffering from
Designed by Rafael Viñoly, significant ‘vortex shedding’ Gary
Pomerantz
the building is a perfect square, even under relatively low winds.
with sides of 28.5m, and this This effect occurs as wind A super-slender building has
regularity is echoed by the 3m x moves past a building, creating a very small floorplate, so if
3m windows punched into the a fluctuating low-pressure we can minimise the space
frame, six on each side of the area behind it and causing it to requirements of the MEP,
building. “It’s quite astonishing vibrate. The engineers’ solution that’s a huge advantage for the
to see a structure so pure,” was to leave the glazing out owner. Residential buildings
says Hezi Mena, senior vice of the mechanical floors to are not designed like offices.
president of building structures allow air to pass through the With an office, you want the
at WSP | Parsons Brinckerhoff building at regular intervals, space to be very flexible so it
in New York. “We tried to effectively making it more can accommodate different
simplify the structure as much aerodynamic. “It’s similar to types of tenant, so you build
as possible so as not to conflict making holes in the sail of a extra space into the ceilings
with the architect’s vision.” boat,” explains Silvian Marcus, and mechanical rooms. With
director of building structures residential, it’s very specific.
The structural solution
at WSP | Parsons Brinckerhoff, Everything just needs to fit
developed by the WSP |
the principal in charge of the perfectly.
Parsons Brinckerhoff team
project. “Instead of making
does have a pleasing simplicity, On these luxury towers,
the building even stiffer to
though this belies the extensive there’s a very sleek look that
overcome the movement, we
testing and refinement that has to be maintained and
flow with the wind.” There are
went into developing it. 432 we have to coordinate with want – they don’t have to work residence – if you’re 1,000ft up, The slenderness is not the
also two tuned mass dampers
Park Avenue is made of two the architect’s vision. If you’re around the systems. But the you can’t open your windows only challenge with these
on the 84th floor, weighing
high-strength concrete tubes. comfortable but you don’t see dimensions of the rooms are for fresh air because it’s a buildings – 1,400ft is a long
1,300 tonnes. Supported on
The interior tube forms the what’s making you comfortable, very large, so we have to work different climate zone up there. way to distribute power and
cables and hydraulic cylinders,
building’s core, measuring that’s a good design. One of out how to distribute air around Last winter the temperature water. If you ran a column of
these concrete weights counter
9m x 9m, containing the lifts the toughest parts of what we those spaces without breaking in New York didn’t rise above water up the whole length of
the building’s movement
and egress stairs. This is the do is fitting everything in the them up or putting systems in freezing for six weeks. But the building, the pressures
and slow its acceleration to
backbone of the building. same space. A building like 432 the middle. You have to do it we have to make sure our would be enormous. At 432
acceptable limits.
Its reinforced-concrete walls Park Avenue is put together in a delicate way, rather than design provides comfort Park Avenue, we’ve essentially
impart considerable stiffness, Floor-to-ceiling heights like a watch. One solution is to blowing air across the room broken up the building so it’s
in the apartments are a very everywhere in the space, no
their thickness varying from put the ductwork or pipework and giving people’s hair the matter what. It can’t be a little really a stack of six smaller
760mm at the base to 300mm generous 3.8m, 1m higher in the ceiling. But with 15ft 6in Einstein look. We carry out high-rise buildings. That
than is conventional in New cold if you’re near the window,
at the top. The outer tube is ceilings, you don’t want to give extensive modelling to simulate and these are big pieces of way we keep shaft sizes and
the tower’s perimeter beam- York. This not only adds to the any of that up because that’s air flows, using the same mechanical rooms smaller,
prestige of the apartments, it glass, so condensation was a
and-column frame, which is what sells the space. programs that are used to real concern. We did many, and it allows us to control the
also incredibly stiff, even with also maximises lateral living design wings on jet aeroplanes. pressures better.
space. The extra height allowed We designed the building many studies on exactly how
the windows punched through systems so that people can set We also have systems to to position the air slot so Every building is a prototype,
it. At every 12th floor these the engineers to add a second introduce outdoor air into each
return to the access stairs in the up their homes however they that the air would bathe the but the systems we design for
tubes are joined by stiffening glass in warm air to minimise these super-tall luxury buildings
beams, accommodated in the building’s core, helping to keep
the downdraughts. We even will eventually filter down to
double-height plant rooms
to avoid encroaching on the
it compact, and resulting in
250ft2 of additional living space
per floor.
“IT’S SIMILAR TO MAKING “ONE OF THE TOUGHEST PARTS introduced air down low in very
concealed devices so that if
the more typical ones. We’re
setting a new standard.”
apartments themselves. In fact,
WSP | Parsons Brinckerhoff has HOLES IN THE SAIL OF A BOAT… IS FITTING EVERYTHING IN THE any cold air does fall down the
glass, it hits that warm air on the
managed to remove all interior
columns, giving the occupants
complete flexibility in how the
WE FLOW WITH THE WIND” SAME SPACE. THIS BUILDING IS floor and that warms it back up.

living spaces are configured. SILVIAN MARCUS, WSP | PARSONS BRINCKERHOFF PUT TOGETHER LIKE A WATCH”
62 63
 RD 53
NA 53W
O
DESIGNING SKYSCRAPER CITIES ///

RETURN TO SLENDER ///

LE
HEIGHT HEIGHT

250M 320M
6
5 RE ET ASPECT RATIO

10.5:1
ASPECT RATIO

13:1
ST 56 Leonard Street has only
just topped out but it’s
already one of the most
distinctive landmarks on the
The engineering team’s
solution is to use a very strong
concrete structure, concealed
to allow a completely glazed
53W53 is not just a super-
slender tower but a work of art
– as befits a building that will
sit above New York’s Museum
investigated how to create the
same aesthetic in concrete
instead – “the first time that
a diagrid structure of this
Lower Manhattan skyline. exterior with views from almost of Modern Art, and even magnitude and complexity
The building is a staggered every angle. The central house 50,000ft2 of additional has been done in concrete,”
series of irregular boxes, with core is linked to the external gallery space in its lower floors. notes Oliveira.
cantilevers ranging from columns by outriggers at the Rising gracefully to a height of Aside from the complex
10ft to 25ft, designed by mechanical levels 32 and 46. 1,050ft (320m) over Midtown, structural gymnastics, the team
Swiss architects Herzog & de At the top, is the ‘swimming it tapers at gently shifting also spent considerable time
Meuron – the practice behind pool’ – a slosh damper filled inclines. Randomly spaced evaluating how 53W53 could
the ‘Bird’s Nest’ Olympic with 130,000 litres of water diagrids roam freely up the actually be delivered. Because
stadium in Beijing. When to temper the building’s façade, to be reflected in the of its complexity, construction
complete, it will provide 145 movement in the wind. unique geometry of each of will take more than five years,
luxury apartments in the Supporting the cantilevers the 139 apartments. around double the programme
TriBeCa district, conceived was one of the biggest But that diagrid is not only for a more conventional
by the architect as “houses conundrums for Mena’s an aesthetic flourish. The design. One of the biggest
stacked in the sky”. team. For the smaller ones, slenderness of the building challenges was designing
the thickness of the concrete means that there is no room the nodes where different
floor slabs provides sufficient for superfluous structure: structural components would
support. For the larger ones high-strength concrete and join. Reinforcement for perhaps

“EVERY FLOORPLATE HAS TO above 15ft, there are additional

beams, and for the very
reinforcing steel will be used
to construct a shear-wall core,
seven or eight elements had
to fit into the same node, and

BE ABLE TO SUPPORT ITSELF, largest, a Vierendeel truss – a

perpendicular column that
engages two floors, without
but the façade has to play an
important supporting role too.
then the concrete had to be
able to flow freely to enclose it
and produce a sound structure.
SO WE HAD TO TREAT EACH obstructing layouts or views.
Throughout the structure, there
This presented an interesting
challenge for the engineering
team, not least because
Oliveira’s team worked closely
not only with the architect but
ONE IN AN INNOVATIVE, are many ‘walking columns’,
where loads are transferred
architect Jean Nouvel was also
adamant that the building’s
the construction team, which
included commissioning a
IMAGINATIVE WAY” from one location to another
as they progress down the
complex façade should be
a genuine expression of the
mock-up of the rebar. “Rather
than just coming up with
HEZI MENA, WSP | PARSONS building. There are no dividing structure beneath. “Normally solutions that looked good
BRINCKERHOFF shear walls in the apartments we are the ones dictating where on paper, we assessed the
at all, to allow residents to lay the columns go but this was the constructability of the job too.
out their living spaces as they opposite,” explains Gustavo That’s not normally part of the
The design started out as a wish, or to combine apartments Oliveira, vice president at engineer’s role but this is such
relatively regular rectilinear horizontally or vertically. WSP | Parsons Brinckerhoff in a unique building, it needed a
shape, but it evolved on a The greatest cantilevers New York. “We couldn’t add unique approach.”
weekly basis until no two are at the top of the building. diagrids in, we had to mimic
floorplates are alike. “Just by The uppermost 10 floors each what was on the façade, so it
looking at the structure, you comprise just one apartment, was an iterative process with
can see it presents many known as ‘sky villas’. “It won’t the architect. We had never
structural challenges,” says Hezi feel as if each occupant is approached a building that
Mena. “It’s like a large sculpture. living in a high-rise building way before.”
There was no simple solution
for the whole building. Every
but in a house in the country,”
says Mena. “They will have
The other unusual feature
of 53W53’s diagrid is what it
“THIS IS THE FIRST TIME THAT A DIAGRID
floorplate has to be able to
support itself, so we had to
views all around, and they
won’t really be aware of who’s
above or below them. It will be
is made of. Nouvel’s original
design was intended to be built STRUCTURE OF THIS MAGNITUDE AND
treat each one in an innovative,
imaginative way.” a very different experience to
your average New York City
in steel. But the floor-to-floor
heights of a steel structure
would have limited the number
COMPLEXITY HAS BEEN DONE IN CONCRETE”
apartment.” of storeys too much, so GUSTAVO OLIVEIRA, WSP | PARSONS BRINCKERHOFF
WSP | Parsons Brinckerhoff

64 65
DESIGNING SKYSCRAPER CITIES ///

* CHINA IS LEADING

SECRETS OF THE MEGA-TALL ///

i r o n m e n t a l core mnust7%be* THE NEW WAVE OF
TOWERS RISING TO
enverformance less tha 500m AND BEYOND.
p BUT LOCATING
SERVICES SUCH AS
LIFTS AND COOLING

flofiocripelnactye TOWERS WITHIN

THESE SLENDER
ef thermal efficiency GIANTS HAS REQUIRED
SOME SERIOUS
LATERAL (AND
p r o o f VERTICAL) THINKING
futauirnes-t energy
ag price rises
ew lectric SECRETS OF THE

MEGA-TALL
a s i n g g l o b a l iring??al
incrteemperatures
f America was the birthplace Jakarta … Every one of them wants to the buildings life day and night. A pure
I of the skyscraper, China is be number one of some kind, so that the office tower has no life at night or at the
undoubtedly the home of the whole world remembers their landmark weekend.”
super-tall tower. The Council for Tall towers. That’s why developers and city For the services engineer, however, this
Buildings and Urban Habitats defines a planners are building mega-tall.” makes buildings much more complicated.
tower as ‘super-tall’ when it tops 300m. But buildings are not only getting taller, They must overcome not only the
So far, 97 have been completed around they are also becoming more complex. gargantuan pressures involved in pumping
the world and 36 are in China. Of the With architects and developers seeking to water up the best part of a kilometre into
41 super-tall towers under construction, stand out, ‘iconic’ shapes are the norm – the sky or the combined resistance of
27 are in China too. By 2020, it will be no two buildings are the same. And while hundreds of metres of electrical wiring,
home to 14 of the tallest 20 buildings in 90% of high-rise buildings were single-use but also serve the potentially conflicting
the world. offices before 2000, now 80% of the needs of different user groups, while fitting
Vincent Tse has a front-row seat for mega-tall towers under construction are all the kit into the smallest possible space.
China’s extraordinary high-rise boom, as multi-use, combining commercial space “As buildings get higher and higher, with
managing director of building systems for with luxury hotels, service apartments, retail mixed-use, it’s like a jigsaw to fit everything
WSP | Parsons Brinckerhoff in the China and leisure spaces. within the core,” says Tse. “The majority
region. Of the CTBUH’s projection of This is partly for technical reasons, says of buildings have more than 100 storeys
the world’s 20 tallest buildings in 2020, Tse, and partly commercial. “All towers and there might be seven different
his team has worked on 11, providing full will change shape as they get higher to components.” What’s more, advances
building systems design consultancy on six minimise the impact of the wind. The on one project can only ever serve as
and partial consultancy on a further five. floorplates will be smaller in the upper inspiration for the next one: solutions can
He sees the era of the ‘mega-tall’ floors, so most mega-tall towers will have never be replicated. “If you try to copy, you
building of 500-600m fast approaching. hotels, CEO offices and observation decks will make a mistake.”
“It’s mainly due to the competition among at the top. Or there will be apartments in Tianjin CTF Financial Centre will be
all major world cities – Seoul, Jeddah, the middle of the tower rather than just 530m tall, with retail and parking space
Dubai, New York, Kuala Lumpur, Beijing, offices, to give a higher cash return. Having in the podium and 100 storeys of offices,
Shanghai, Shenzhen, Taipei, Bangkok, multiple building functions also gives service apartments, a hotel and club all

Lotte World Tower in Seoul by KPF

66 67
 stacked on top, providing a total floor area The high costs of constructing mega-tall world record – for the fastest elevator
“THE BUILDING IS
DESIGNING SKYSCRAPER CITIES ///

SECRETS OF THE MEGA-TALL ///

of 350,000m2. The problem is that the towers means that space at their upper ever installed. This 530m tower will be
space is not necessarily where the services reaches is typically only within reach of the city’s tallest building, and will include
engineer would like it to be. “The most
difficult thing when designing the services
the wealthiest occupiers, which means
international grade AAA offices, 6-star
grade A office space, service apartments,
a club and the Rosewood hotel. There will
TAPERED NOT ONLY
for tall buildings is always the shape,” says
Tse. “This is a very slender tower and by
hotels and luxury apartments. There can
therefore be no compromise on quality
certainly be no waiting around for the hotel
guests, who will occupy the top 16 floors:
AT THE TOP BUT AT
the time you reach the top, the whole
building shrinks like a bowling pin. At
either. The occupants of mega-tall towers
do not expect to have to queue for the lift,
the shuttle serving the hotel will climb at
20m per second, twice the speed of the lift THE BOTTOM TOO, SO
the top levels, the floorplate is very small
and the core is only around 19m square.”
The smaller floors lend themselves to
or to have to cram in once it arrives. Due
to complete in 2016, the CTF Financial
Centre in Guangzhou is about to set a
to the observation deck of the Burj Khalifa
in Dubai. THE FLOOR AREA IS
hotel accommodation rather than offices,
but how to fit the hotel lobby – and
NOT THAT LARGE AT
its considerable vertical transportation
requirements – at the point where the core
THE BASE”
is at its thinnest? EDDIE LEUNG,
The solution was to put the hotel at WSP | PARSONS BRINCKERHOFF
the top, but with the hotel lobby below
the service apartments, keeping the core
as compact as possible. It is shaped like
two square tubes, one inside the other.
The inner part of the core contains all the
building systems, local lift shafts and the
fire escape stairs, and runs the full height
of the building. The outer part of the core
contains the shuttle elevators: “The big
core stops when you get to the hotel lobby,
and by the time you get to the hotel floors,
everything’s in the small core, which is tiny,”
explains Tse.

CBD Z6 Sino-Ocean Centre, Beijing

Architect Kohn Pedersen Fox’s midway through, even when the design is
crystalline design has chiselled setbacks, so relatively advanced. Beijing’s 406m CBD
that the floorplates become progressively Z6 Sino-Ocean Centre will be the city’s
smaller – which means that the core must second tallest building when it completes
too. To make it as efficient as possible, a in 2018, and was originally planned as a
vertical transportation system of shuttle single-use office building. Following a
elevators will whisk building occupants to change of ownership, it now includes a six-
sky lobbies at different heights. The offices star MGM hotel on levels 45-62, executive
in the lower storeys will be served by a apartments on 65-67 and a club at the
double-deck shuttle and local elevators, top. This meant a radical rethink of the
while the service apartments, hotel and vertical transportation system in order to
club on the upper storeys will have their make the overall building design function
own separate shuttles. “When you need as it should. The 36 office floors are now
more elevators and better performance, divided into four zones, with the lower two
you need to increase the size of the core,” served by direct lifts from the base. To
says Herbert Lam, director of building access the third and fourth office zones,
“AS BUILDINGS GET systems at WSP | Parsons Brinckerhoff
in Hong Kong. “But the rule of thumb is
occupiers will now transfer via a double-
deck sky lobby at floors 31 and 32. The

HIGHER AND HIGHER, that each floorplate must have a minimum

efficiency of 70% usable office floor area.
That’s a constant balancing act for the
introduction of the sky lobbies made all
the difference, says Eddie Leung, director
of building systems at WSP | Parsons
WITH MIXED-USE, services engineer. It requires intelligent
planning to optimise the central core to
Brinckerhoff. “The building is tapered not
only at the top but at the bottom too, so
IT’S LIKE A JIGSAW make sure the performance of elevators
and building systems is excellent, and at the
the floor area is not that large at the base.
We needed to minimise the number of
TO FIT EVERYTHING same time that the floorplates are efficient
with high rental returns.”
lift shafts, and introducing the sky lobbies
allowed us to eliminate two of them and
WITHIN THE CORE” As mega-tall projects are larger and take
more time than smaller buildings, they are
shrink the core.”

VINCENT TSE, WSP | PARSONS Guangzhou CTF Finance Center and Rosewood Hotel by KPF very vulnerable to changes in the market.
BRINCKERHOFF Changes of use are not uncommon

68 69
 Managing pedestrian flow through Maintaining a comfortable internal
DESIGNING SKYSCRAPER CITIES ///

SECRETS OF THE MEGA-TALL ///

the lobby is also critical with such a environment is not easy in a glass tower,
large building. Leung’s team carried out especially where it’s not possible to open
pedestrian modelling studies to identify
any pinch-points as people enter from
street level and from the subway below.
the windows. In temperate climates,
outside air can be used for low-energy
night-cooling. But in a humid tropical
“IF YOU SHUT OFF THE AIR-CONDITIONING
To avoid overcrowding, the base is divided
into three different lobby areas. One is
climate – in Singapore, for example –
allowing wet indoor air to enter at night
AND OPEN THE WINDOWS AT 7PM IN A
dedicated to the hotel, one to office
zones 1 and 2, and the third for the other
would result in an indoor rainstorm
when the air-conditioning comes back
WARM, HUMID CLIMATE, WHEN YOU
office zones, the serviced apartments and
the club.
on the next morning, as the liquid in the
air condenses on the cooler surfaces.
COME BACK THE NEXT DAY, I GUARANTEE
A challenge for all mixed-use towers
is how to reconcile demand for some
“Opening louvres to ventilate a building
may work in New York, but not in warm, EVERYTHING WILL BE WET.
functions to remain separate while others humid climates such as Singapore, VINCENT TSE, WSP | PARSONS BRINCKERHOFF
are shared. For example, the hotel at the Guangzhou or Taipei,” says Tse. “If you
CBD Z6 Sino-Ocean Centre needed shut off the air-conditioning and open
separate lift capacity for its guests, but the windows at 7pm, when you come
had to connect directly to the communal back the next day, I guarantee everything
service elevator too. The hotel also will be wet.”
required a separate chiller plant, while Instead, the first step is create a highly
the hotel operator imposes even greater thermally efficient building façade to
requirements on building systems. manage energy gain and optimise
Achieving a 6-star level of service at such a daylighting, and design innovative building
great height meant overcoming extremely systems to optimise energy consumption
high hydraulic pressures – achieved by inside the building, such as variable speed
splitting water systems into several zones. pumping and fan systems. Power can be
“At the top, the walls incline at an angle of regenerated from elevator systems, and
4° so the floorplate shrinks every floor,” grid supplies supplemented with renewable
says Leung. “All the pipework around the wind and solar energy. “With all of these
guest rooms needed to be inclined. There’s techniques, it is possible to achieve LEED
no typical floor.” accreditation,” says Tse.
Tall buildings are often designed to But the most sustainable feature of
maximise the potential of tight sites, a high-rise design is adaptability. “The
which leaves little space for essential Empire State Building is 84 years old, and
infrastructure. Their iconic nature also when it was designed there was no chilled
means this must be hidden away. On water, no air-conditioning, no sprinkler
Beijing’s 528m China Zun Tower, now systems, no IT,” he points out. “So we
under construction, the location of the need to design buildings that are very
cooling tower gave the engineers a major flexible. We have to ensure that the space
headache. The building is on a tight site, provision for building systems will be
it does not have a podium and the top is sufficient for future changes.”
a sealed garden, so the only option was
to locate it within the building itself. But a
mega-tall tower must also be careful not
to attract the wrong sort of attention: “In
Beijing, the outdoor temperature in winter
will be well below -10°, and if people see
the plume from the cooling towers, they
will think the building’s on fire,” says Tse. “So
we have designed and developed a plume-
less cooling tower instead by using the
ice storage system, so that in the daytime,
we will not need to operate the chiller or
cooling tower.”
There’s one more complicating factor:
building systems engineers are on the
frontline of improving environmental
performance of buildings and reducing
their energy and water use. This can no
longer be ignored on projects – partly to
mitigate climate change, but also to future-
proof buildings against energy price rises,
increasing temperatures and demand from
global occupiers for ‘green’ buildings.

China Zun Tower. Image courtesy of KPF

70 71
ENGINEERING
GLOBAL
SKYLINES

WHAT DOES THE FUTURE HOLD

FOR SKYSCRAPER CITIES? WE SEE
A WORLD OF POSSIBILITIES.
Talk to us: www.wspgroup.com/highrise