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ENERGY EFFICIENT BUILDINGS

 In this respect, we need to know the life cycle of building. Building life cycle is divided into
three main phases such as the prebuilding phase, building phase, and post building phase.
These phases have some processes.
 Prebuilding phase includes the appropriate site selection, site planning, building form,
building plan, and appropriate space organization, building envelope design choosing
energy-efficient building materials, energy-efficient landscape design, obtaining raw
materials for building material, manufacturing, and transporting them.
 The building phase includes the construction and usage processes of the building.
 The post building phase is the phase following the completion of building usage. In this
phase, we have the demolition, recycling, and wipe-out of the building. The methods applied
so as to fulfil the energy efficiency of buildings depending upon life cycle phases.
APPROPRIATE SITE SELECTION

 The locations of the

hemisphere, slope, and
aspect are important design
parameters. Location of the
building determines the
microclimate conditions
which has very important
role in building energy
efficiency, as it is important
for learning, climatic values
such as sun radiation, air
temperature, air circulation,
and humidity, which effect energy costs.
 The site of building and distance between other buildings are one of the most important
design parameters, which affect sun radiation amount and air circulation velocity around the
buildings. For this reason, the site of the building in the area should be determined to benefit
and defend from the renewable energy resources like sun and wind
 In order to provide adequate protection from the prevailing wind and sun, the orientation
of buildings on the land needs to be appropriate to the climatic conditions of the region.
 View lots are the most common to create challenges with home energy use. Ideally southern
views are going to be beneficial and western views the most detrimental. Additionally, the
shape of the lot can affect the length axis of the home with positive or negative effects on
energy use.
SITE PLANNING

 The distances between buildings highly affect the energy performance in the usage phase of
building. The fact that a building remains within the shading space of other buildings
influences the utilization of solar rays and will raise the consumption of energy. In order to
utilize solar radiation, building spaces must not be less than the tallest shade height of other

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buildings. Besides, the position and distance of other buildings affect the speed and direction
of wind on building, and this impacts the energy performance of building.
 Orientation of building affects the ratio of the solar radiation gain of building sides,
consequently the total solar radiation gains of building. In addition, the side of buildings
affects wind amount, consequently, affecting natural ventilation possibility and heat loss
amount by convection and air lack. For this reason, according to the necessities of that
region, buildings must be oriented for avoid of or benefit from the sun and wind according
to the conditions
 Once property has been selected, the structure should be oriented to capitalize on the
seasonal arc of the sun. In the northern hemisphere its preferred to orient windows to the
southern exposure and prevent heat gain on the east and west elevations.
BUILDING FORM

 Energy performance of building is affected by such factors as its form, volume surface rate
and frontal motions. There is a direct relationship between the geometrical shape and
energy performance of building.
 The shape of building which is a considerable factor affecting heat loss and gain can be
defined through geometrical variables making up building such as the proportion of building
length to building depth of the building in the plan, building height, type of roof, its gradient,
front gradient, etc. Heat loss-gain of building may rise and decline depending upon the
proportion of the surfaces constituting environment to volume.
 The shape of building is important in areas that have different climate conditions. In cold
climate regions, compact forms should be used which minimize the heat loss part. In hot-dry
climate regions, compact forms and courtyards should be used which minimize heat gain
and helps to provide shaded and cool living spaces. In hot-humid climate region, long and
thin forms whose long side oriented to the direction of prevailing wind makes possible
maximum cross-ventilation. In mild climates, compact forms, which are flexible more than
the forms used in cold climate regions.
BUILDING PLAN AND APPROPRIATE SPACE ORGANIZATION

 Building plan and shapes should be effective in energy conservation. Therefore, buildings
should be formed to ensure minimum heat gain in warm seasons and maximum in cold. Due
to simple plan types such as square or rectangle having a reduced surface area, their heat-
loss and -gain are also reduced.
 In the building design, stratification can perform zoning depending on buffer zone, sanitary
spaces, noise level, lighting level, and heating need. Therefore, areas with many users and
which are used throughout the day should face southerly direction. Thermal zoning and the
settlement of indoors can be designed in a way to raise mutual air motion
 Deep plans and the use of too many dividing elements may restrict air motion in
environment.
 Increase Efficiency - Increased energy efficiency is available for a number of building systems
but this is where cost-benefit analysis becomes important. Depending on the success of the
previous strategies, there may be a point of diminishing returns from the investment in
higher performance products. Windows and HVAC systems are the main items to fall into
this category
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BUILDING ENVELOPE

 Building envelope is the components such as wall, ceiling, ground, window, and door which
separate building (conditioned space) from outdoor and let heat energy transfer into inside
or outside.
 The skin of building performs the role of a filter between indoor and outdoor conditions, to
control the intake of air, heat, cold, and light. Building envelope should minimize the heat
loss in the winter and the heat gain in the summer.
 To reduce operating energy use, high-efficiency windows and insulation in walls, ceilings,
and floors increase the efficiency of the building envelope, (the barrier between conditioned
and unconditioned space).
 Have an envelope capable of isolating or buffering it from heat, cold and humidity,
consistent with the climate zone.
 In temperate and cold climates, walls, roofs and floors should be heavily insulated, with
double-glazed windows, as well as minimal air infiltration and cold bridges. Insulation has
one of the highest paybacks of any investment, especially in smaller buildings with high skin-
to-volume ratios. There should be a vapour barrier on the warm side of the insulation.
Glazing on all faces should be covered at night with interior or exterior air-tight movable
insulation, such as insulating curtains, shutters and panels.
 Larger, multi-floor buildings have a more favourable ratio of volume to skin than smaller
buildings and are thermally more cost-effective per occupant.
 In hot, humid climates, wall cavities must breath to the exterior to prevent the build-up of
mildew and mold.
 Light coloured roofs and walls reflect unwanted solar heat gain, as well as reduce the local
Urban Heat Island Effect. Shade from trees and other vegetation is often essential.

CHOOSING ENERGY-EFFICIENT BUILDING MATERIALS

 Building materials both in the production phase should have energy-efficient features in the
use phase. Energy-efficient building material properties are described below.
 Local material: In the total energy consumption of constructions, the amount of energy spent
for transportation of the construction materials to construction sites is considerable and also
affects the constructions’ energy efficiency and economical cost. For this reason, if the
construction materials are local material and are manufactured in nearby places to the
construction site as much as possible, energy consumption in transportation will decrease
and that saving in transportation will give the construction an important ecological quality
 Recycled resources: A large amount of energy is used in manufacturing many building
materials. In the manufacture of building material, using recycled sources instead of the
sources which are not newly processed material provides a considerable preservation of raw
material and also a considerable amount of energy saving. Recycling building materials are
essential to reduce the embodied energy in the building; for instance, the use of recycled
metal makes considerable energy savings between the rates of 40 and 90% comparing the
material produced from natural resources.

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 Materials manufactured through low density industrial processes. A large proportion of the
total energy used during the building life cycle is consumed during the production of building
materials
 Natural materials are quickly obtained from renewable resources: Generally, the energy
content of natural materials is lower than that of artificial materials since these materials are
manufactured with less energy and labour cost. Such kinds of materials which are easy to be
locally provided are generally among the renewable resources. Such vegetal materials used
in constructions for instance, wood, bamboo, reed, straw, rye stalk, sunflower stalk,
mushroom are the natural materials which are quickly gained from renewable sources.
 Labour intensive materials: Using highly qualified man power in manufacturing materials will
reduce the processes based upon industry, and accordingly decrease the energy
consumption. Materials manufactured by using renewable energy resources: especially
renewable energy resources (solar energy, wind energy, etc.) instead of fossil fuels should
be preferred as a primary energy supplier in the manufacturing process. For example, the
adobe brick is dried using solar energy after it is moulded.
 Materials consuming less energy during the worksite process: The management of worksite,
the need for electricity energy, and machines in operation, heating, and lightening affect the
energy consumption of the worksite. As a result of the increase in mechanization in
worksites, the electricity consumption has increased considerably as well.
 Use of durable building materials: Use of durable materials in the buildings makes them
more resistant and long-lasting against various factors. This delays or eliminates the need of
renewing material or maintenance due to impairment and aging. In this way, it is saved from
the energy spent for the material to be used in maintenance or renewing.
 Building materials with high thermal insulation capacity: With the choice of building
materials whose thermal insulation capacity is high, the energy amount that the construction
consumes in its usage stage will be decreased. As mentioned as examples are opaque and
translucent insulating materials.
USAGE RENEWABLE ENERGY RESOURCES WITH PASSIVE TECHNIQUES

 Renewable energy sources (sun, wind, biomass, biogas, geothermal energy, hydro, wood,
ocean thermal, ebb and flow, wave, sea flows) are the energy resources that can be used by
all living creatures on the earth and accepted as inexhaustible thanks to their continuous
renewal. It is possible to benefit from renewable energy resources with passive and active
methods.
USAGE RENEWABLE ENERGY RESOURCES WITH PASSIVE TECHNIQUES:

 Passive heating: Passive solar heating systems are categorized by the relationship between
the solar system and the building. There are three categories of passive solar heating
systems: direct gain systems, indirect gain systems, and isolated gain systems
 In the passive solar heating system, building elements (windows, walls, floors etc.) collect
and store heat and then distributes indoor space.
 Passive cooling and ventilation
 Ventilative cooling
 Radiant cooling

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 Evaporative cooling
 Dehumidification: The removal of water vapour from room air by dilution with drier air,
condensation, or desiccation.
 Mass-effect cooling: The use of thermal storage to absorb heat during the warmest part of
a periodic temperature cycle and release it later during a cooler part.
 Natural lighting: Natural lighting in buildings is carried out through a most basic windows
and skylights. Choice of direction in the windows and roof lighting is important. The most
suitable directions for natural lighting are south and north. The north direction is not
exposed to radiation, but can always get daylight in the same quality. In the west and east
directions, the sun radiates in horizontally and makes it difficult to control. In the south
direction, the effect of the sun is permanent and sun rises at a right angle compared to the
west and east directions. Therefore, it is easy to control.
USAGE RENEWABLE ENERGY RESOURCES WITH ACTIVE TECHNIQUES:
Solar energy thermal systems: Solar energy thermal systems (effective solar thermal systems) are
the aggregation of mechanic and/or electronic components that convert solar radiation into thermal
energy via collectors, make it possible to directly use this energy with water, air, and a similar fluid,
or make it usable by evaluating it in a storage unit. Solar energy-efficient thermal systems are used
for heating pool water, preheating of climatization air and heating environment. The general
operation principle of thermal systems is based on collecting heat via collectors, storing thermal
energy to be able to use later if needed and distributing it to relevant fields
Solar water heating systems: These systems are composed of the elements that transform solar
radiation into thermal energy, keep and distribute this heat in an aquatic environment. In contrary
to the fact that systems show differences depending on the complexity and magnitude of necessity,
all of the solar water heating systems are based on heating water, storing, and distributing it. As the
hot water produced with the transformation of solar energy can be directly used for having a bath,
laundry, and washing dishes depending on the characteristics of the system, it can also be used for
supporting the conventional heating system.
Photovoltaic systems: The aggregations of the components that produce electric energy via
collectors from solar radiation and make this energy usable are called photovoltaic (PV) systems.
With simple or complex structuring, PV systems are used to produce electricity in a large number of
different fields such as road lighting, lighthouses, vehicles, constructions, and electric power-plants.
A photovoltaic system generates electric energy, stores the produced energy for necessary
conditions and safely transfers this energy to the areas of usage. By being placed on fronts and roofs
of buildings, photovoltaic batteries convert the solar energy coming to these surfaces into electric
energy.
The active use of wind energy systems in buildings: Wind energy is the fastest-growing renewable
energy source in the world. Wind energy is a clean fuel source and does not produce atmospheric
emissions that cause acid rain or greenhouse gasses. Wind energy is an inexhaustible energy source.
More recent developments in this technology have allowed wind turbines to be utilized in building
design. Consistent with the high performance approach to building design, the use of wind turbines
on high buildings is significantly enhanced by their integration with building architecture.

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Use of geothermal energy in buildings: Geothermal energy is used in heating and cooling in houses,
greenhouse cultivation, and agriculture. Geothermal energy systems are applied in three different
ways according to application methods such as heat pumps, downhole heat exchangers, and heat
pipes. Their common usage in buildings is in the form of heat pipes.
Use of hydrogen energy in buildings: Hydrogen energy can be used for heating houses, providing
hot water, cooking and meeting electricity need. In order to use hydrogen here, we first need to
produce it, then store and transfer it. Hydrogen can be produced from such renewable energy
sources such as sun, hydroelectric, wind, and geothermal.
Use of biomass energy in buildings: Biomass is a strategical energy resource, which is renewable
and environment friendly, can be grown everywhere, enables socioeconomic improvement, and can
be used for power generation and for obtaining fuel for vehicles. Biomass is utilized in the energy
sector by being directly burned or its fuel quality is increased with various processes and thus gained
alternative biofuels (easily movable, storable, and usable fuels), which are equal to existing fuels.
ENERGY-EFFICIENT DESIGNING METHODS IN BUILDING PHASE

 Building phase includes the construction and usage processes of building. Building phase is
possible with preferring building techniques consuming less energy and using energy-
efficient equipment.
 Supporting multiuse improvement: Sustainable development advocates the combination of
house settlement, trading area, office, and retail areas. Thus, people get the opportunity of
living next to the places they work and shop. This renders the formation of a community
different from traditional suburbs. 24-hour activity potential also makes the land safer
 Combining design with public transportation: Sustainable architecture on urban scale
should be designed in a way to support public transportation. Thousands of vehicles coming
in and going out the land during daily work pressure cause air pollution and traffic jam and
they need parking areas.
 Using energy-efficient bulbs and energy-efficient appliance: For example, the light-emitting
diode (LED) is one of today's most energy-efficient and rapidly developing lighting
technologies.
 Lighting controls: Lighting requirements reply to a building design. The need for lighting,
when during daytime, will depend on the window size and placement, and the position of
buildings. The need for lighting is decreased by the use of automatic controls, which depend
on the orientation of building windows, the supply of daylight, and usage of the room.
REDUCTION OF WATER DEMAND AND CONSUMPTION
ENERGY-EFFICIENT LANDSCAPE DESIGN

 Through an accurate and conscious energy protected landscape design, it is possible to

reduce the energy cost spent for heating and cooling during summer and winter seasons at
30% [34]. The ground flooring of outdoor and grass has a cooling impact via vapour
transportation. The materials harbouring heat in its body such as asphalt continue to expand
heat following sun and they increase night time radiations. So as to reduce the cooling costs
spent, using such materials that store heat and reflect lights little or shading them against
direct solar rays are among the precautions to be taken

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 In most climates, west-facing glass is particularly susceptible to visual glare and overheating,
and benefits from interior window blinds and shades or exterior fixed or movable vertical
louvers.
Green roofs, trellises and living walls can provide shading, as well as cool the air by evapo-
transpiration, and detain storm water.
BE ADAPTABLE OVER TIME, WITH MATERIALS AND COMPONENTS RECYCLED OR REUSED AT THE
END OF THEIR USEFUL LIVES.

 The building foundation, structure and shell should be built to last a century or more in order
to shelter different users and needs over time. Buildings should be constructed of materials
that are reusable or recyclable. Movable, short-lived and personalized building components
should be flexible on a daily and seasonal basis, as well as adaptable over the years. Buildings
should recycle grey water for toilet flushing and irrigation of plants. Occupants should
recycle inorganic and compost organic waste, as well as minimize water consumption.

SUSTAINABLE ARCHITECTURE AND ENVIRONMENT – NOTES, LIMA M.T.