Sustainable Sites
Learning Objectives
✓Construction activity pollution prevention
✓Site assessment
✓Site development-protect or restore habitat
✓Open Space
✓Rainwater management
✓Heat island reduction
✓Light pollution reduction
Overview
✓Rewards decisions about the environment surrounding the building
✓Emphasize on restoring project site elements, integrating the site with local
and regional ecosystems, and preserving the biodiversity that natural systems
rely on
Prerequisite
Construction Activity Pollution Prevention
Intent
✓ To reduce pollution from construction activities, addresses mainly
• Erosion
• Sedimentation
• Air borne dust generation
Erosion: Loss of top soil
✓ Top soil supports vegetation
✓ Increased fertilizer requirement for the
landscape and hence increased
environmental damage
✓ Reasons of Erosion: Storm water runoff,
wind, construction vehicle traffic, steep
slopes etc.
Sedimentation: Water Pollution
✓Sedimentation: Addition of solid particles in water bodies.
Sediments from construction site are rich in contaminates and
pollutes the water bodies
Air Pollution
✓ Air borne dust generation:
• Erosion due to wind pollutes the
air with particulate matter and
suspended particles
Strategies & Implementation
Erosion & Sedimentation Control Plan
✓ Projects should develop and Implement Erosion and Sedimentation
Control (ESC) Plan which complies with EPA 2012 Construction General
Permit or local standards
Protecting & restoring top soil:
✓ Stock Piling: Topsoil is removed from the site and piled in safe place, replaced
by free drain gravel and finally restored after the construction
Stabilization Strategies:
✓ Temporary Seeding: Plant fast growing grasses to temporarily stabilize the soil
✓ Permanent Seeding: Plant grass, trees and shrubs to permanently stabilize the soil
Stabilization Strategies contd:
✓ Mulching: Spreading material like sawdust, straw, hay, grass, wood chips or gravel over the topsoil
to stabilize it.
Structural Strategies:
✓ Silt fencing: Construction post with fabric filter media to remove sediments from storm
water runoff.
Structural Strategies contd:
✓ Sediment Traps: A cavity where sediments from storm water are allowed to settled
down.
✓ Sediment basin : same as sediment trap but of larger size
Structural Strategies contd:
✓ Earth Dikes: mound of stabilized soil to divert the run off through the desired direction (ideally
through sediment traps and basins)
Site assessment
Intent
✓ To assess site conditions before design to evaluate sustainable options.
Strategies & Implementation
Conduct a site survey prior to design to assess
✓Topography
✓Hydrology
✓Climate
✓Vegetation
✓Soils
✓Human use
✓Human health effects
Significance
✓Assets such as favorable climate conditions, good
solar access, and healthy plant populations
✓And liabilities, such as unhealthy soils, blighted
structures, pollution sources, steep slopes, and
extreme climate patterns.
Site development - Protect or Restore Habitat
Intent
✓ To conserve existing natural areas
✓ Restore damaged areas
✓ To promote habitat and promote biodiversity.
Strategies & Implementation
Preserve Greenfield Areas
✓ Protect Greenfield areas from disturbance during
development and construction
✓ Restore all disturbed or compacted soils to its original
condition
Restore Previously Developed Site
Financial Support
✓ Provide financial support to a:
• nationally or locally recognized land-trust or
• conservation organization
Open Space
Intent
✓ To create exterior open space that encourages interaction with the
environment, social interaction, passive recreation, and physical
activities.
Strategies & Implementation
Open Space
✓ Open space is a vegetated or 50%
pervious surface which may include
following:
• Pedestrian– oriented paving
• Recreation– oriented paving
• Garden spaces
• Habitats
Maximize Open Space
✓ Reduce hardscape, Increase open space
✓ Achieve the required area by increasing height not width
✓ Cluster developments together
✓ Maximizing open space reduces storm water runoff and heat
island effect
Rainwater management
Intent
✓ To reduce runoff volume
✓ Improve water quality by replicating the natural hydrology
and water balance
Significance
✓ Reduce load on sewage treatment plant
✓ Reduce Erosion, sedimentation, eutrophication and related
environmental impacts
✓ Reducing storm water runoff helps maintain the natural aquifer
recharge cycle.
Eutrophication
✓ Eutrophication is the enrichment of inorganic plant nutrients (e.g. nitrate,
phosphate) in fresh water bodies. It may occur naturally but can also be the
result of human activity (cultural eutrophication from fertilizer runoff and
sewage discharge)
Strategies & Implementation
Green infrastructure / Low impact developments
✓ Rain water management approach which replicates the natural hydrology of the
ground cover is called as Low Impact Development. LID applied to urban planning /
township development or neighborhood development is called as Green Infrastructure
Non-Structural strategies Structural strategies
✓ Promotes natural infiltration of ✓Collect, hold and treat storm
storm water into soil. water
✓ Best suited for sites which has ✓Best suited for urban sites with
sufficient open space space constraint
✓ Example rain gardens, vegetated ✓Example: rainwater cisterns,
swales, reducing impervious areas sediment traps and ponds
and pervious pavement
Impervious pavement
✓ Reduce Impervious surfaces and promote natural infiltration
✓ Use open grid pavement, pervious paving instead of
conventional hardscape surfaces
Rain Gardens
✓ Planted depression that allows rainwater runoff from impervious urban areas like
roofs, driveways, walkways, parking lots, to be absorbed.
Vegetated Filter Strips
✓ Filter strips function by slowing runoff velocities and filtering out sediment and
other pollutants, and by providing infiltration into underlying soils
Vegetated Swales
✓ Constructed open-channel drainage ways used to convey storm water
Bioswales
✓ Landscape elements designed to remove silt and pollution from surface runoff water. They
consist of a swaled drainage course with gently sloped sides (less than six percent) and filled
with vegetation, compost and/or riprap (loose stone).
File:Bioswale.jpg
Vegetated roof
Storm water cistern
✓ Collect, treat and reuse storm water for non potable application
Heat island reduction
Heat Island effect
✓ Thermal gradient between urban and rural areas
Intent
✓ Reduce heat island effect to minimize effects on microclimates, human
and wildlife habitats
Strategies & Implementation
Roof
✓ Consider using vegetated roof instead of conventional roof
Roof
✓ Use High SRI coating on roof surfaces
✓ Flat roof/low slope surfaces shall ✓Sloped roof surfaces shall have
have
•Initial SRI of 39
• Initial SRI of 82
•3 years aged SRI of 32
• 3 years aged SRI of 64
✓ SRI(Solar Reflective Index) refers to the ability of a surface to reject heat.
✓ For a surface to have higher SRI it should have higher emittance and
reflectance or Albedo
✓ Generally construction materials have higher emittance and poor
reflectance. But to have high SRI both reflectance and emittance should be
higher
SRI values for Solar Infrared Solar Infrared SRI
Temperatures Reflectance Emittance
Gray EPDM 0.23 0.87 21
Gray Asphalt Shingle 0.22 0.91 22
PVC White 0.83 0.92 104
White coating, 2 coats, 2 mils 0.85 0.91 107
Non-Roof
✓For Non-Roof use Reflectance factor
SR only
✓Increase vegetated pervious surfaces.
✓ Use open grid pavement/pervious
paving
✓ SR value non-roof surfaces shall be
0.28 or higher for 3 years aged or 0.33
if aged data not available
Non-Roof
✓Shade surfaces by structures, trees, solar
panels
✓Consider using under ground parking,
shaded parking
Light Pollution Reduction
Intent
✓ To increase night sky access, improve nighttime visibility, and reduce
the consequences of development for wildlife and people.
What is light pollution ?
✓Waste light from building sites that produces glare, is directed upward to the
sky, or is directed off the site.
✓Waste light does not increase nighttime safety, utility, or security and needlessly
consumes energy. http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/img/figure7.jpg
Strategies & Implementation
Uplight
✓ Use full cutoff fixtures (shield) in external lighting
Trespass
✓ Reduce light trespass beyond the property boundary.
✓ Comply with the light trespass requirements of Illuminating
Engineering Society and International Dark Sky Association
(IES/IDA)
Interior lightings
✓Use timers and occupancy sensors to switch off unnecessary lights after
occupancy hrs
✓Control Light trespass through transparent surfaces by proper positioning
and selection of lighting fixture or automatically closing the transparent
openings after specified time
Summary
✓ Construction activity pollution prevention
✓ Site assessment
✓ Site development-protect or restore habitat
✓ Open Space
✓ Rainwater management
✓ Heat island reduction
✓ Light pollution reduction
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