Chapter 4: Sustainable Sites PDF

©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Chapter 4 – Sustainable Sites Le...

©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Chapter 4 – Sustainable Sites Learning Objectives At the end of this chapter, candidates will have an understanding of Construction activity pollution prevention Site assessment Site development-protect or restore habitat Open Space Rainwater management Heat island reduction Light pollution reduction 4.1 Construction Activity Pollution Prevention Construction activity pollution prevention is a pre-requisite in many rating systems. Intent: To reduce pollution from construction activities, the prerequisite mainly address erosion, sedimentation & airborne dust generation Significance:  Erosion results in loss of topsoil.  Top soil is rich in biological nutrients and organic matter, which supports plant life. GBA/GA V4/Rev 01 Page 4.1  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co  Loss of topsoil reduces the capacity of the site to support plantation. This may further increase the fertilizer requirement for the landscape thereby making more damage to the environment.  Storm water run-off from the construction site is rich in contaminants because of construction materials and causes water pollution  Erosion due to wind pollutes the air with particulate matter and suspended particles which results in respiratory problems for humans Strategies: Project team should prepare and implement a comprehensive Erosion and Sedimentation Control (ESC) plan complying with EPA 2012 Construction General Permit, National Pollutant Discharge Elimination Scheme or applicable local standardswhichever is stringent. Following are the potential strategies the project team can incorporate. 4.1.1 Stock Piling:Topsoil is removed from the site and piled in safe place, replaced by free drain gravel and finally restored after the construction. Other Erosion and Sedimentation Control (ESC) strategies can be classified into Stabilization strategies and Structural strategies. 4.1.2 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. GBA/GA V4/Rev 01 Page 4.2  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Mulching:Mulching is the process of spreading material like sawdust, straw, hay, grass, wood chips or gravel over the topsoil to stabilize it. Fig 4.1 Mulching done in Walkway of a construction site 4.1.3 Structural Strategies: Silt fencing:Construction post with fabric filter media to remove sediments from storm water run-off. Fig 4.2 A typical Silt Fence in a construction site GBA/GA V4/Rev 01 Page 4.3  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Sediment Traps:A cavity where sediments from storm water are allowed to settle down. Fig 4.3 A typical section of Sediment trap Sediment Basins:Similar to sediment traps but bigger in size. A pond with controlled water release structure to allow settling of sediments from the run-off. Fig 4.4 A Sediment basin in a construction site Earth Dikes: Construct a mound of stabilized soil to divert the run-off through the desired direction (ideally through sediment traps and basins). GBA/GA V4/Rev 01 Page 4.4  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Fig 4.5 A typical Earth Dike Terminologies: Erosion:Erosion is the process by which solid particles on the surface (soil and stones) are moved. Erosion in construction site happens because of storm water run-off, wind, foot traffic, construction vehicle traffic, steep slopes etc. Storm water run-off:The storm water that flows out of the project site boundary through the surface is called as storm water run-off. Sedimentation:Sedimentation is the process of addition of solid particles in water bodies. Sedimentation decreases the water quality and affects the aquatic life. References/Standards: a. EPA 2012 Construction General Permitb. Applicable Local standards 4.2 Site Assessment Intent: To assess site conditions before design to evaluate sustainable options. GBA/GA V4/Rev 01 Page 4.5  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Significance:  Site Assessment identifies both o Favorable conditions such as favorable climate conditions, good solar access, and healthy plant populations o And liabilities, such as unhealthy soils, blighted structures, pollution sources, steep slopes, and extreme climate patterns.  A site assessment informs good design decisions, such as appropriate plants for landscape, orienting buildings to take advantage of prevailing winds and solar access and optimizing the location of rainwater management features.  A well-developed assessment conducted before or during the conceptual design phase may reduce project costs and risks, promote occupants’ health, and honor a site’s unique characteristics. Strategies: Conduct a Site Assessment Considering  Topography: Contour mapping, unique topographic features, slope stability risks.  Hydrology:Flood hazard areas, delineated wetlands, lakes, streams, shorelines, rainwater collection and reuse opportunities,  Climate: Solar exposure, heat island effect potential, seasonal sun angles, prevailing winds, monthly precipitation and temperature ranges. GBA/GA V4/Rev 01 Page 4.6  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co  Vegetation:Primary vegetation types, greenfield area, significant tree mapping, threatened or endangered species, unique habitat, invasive plant species.  Soil: Natural Resources Conservation Service soils delineation, U.S. Department of Agriculture prime farmland, healthy soils, previous development, disturbed soils (local equivalent standards may be used for projects outside the U.S.).  Human use:Views, adjacent transportation infrastructure, adjacent properties, and construction materials with existing recycle or reuse potential.  Human health effects: Proximity of vulnerable populations, adjacent physical activity opportunities, proximity to major sources of air pollution. 4.3 Open Space & Site Development – Restoring Habitat Intent:  Create exterior open space that encourages interaction with the environment, social interaction, passive recreation, and physical activities.  To conserve existing natural areas  Restore damaged areas  To promote habitat and promote biodiversity. Strategies:  Reduce the building footprint. Achieve the required gross floor area by increasing the number of floors.  Reduce the hardscape area and increase the open space GBA/GA V4/Rev 01 Page 4.7 a-b  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co  Restrict the disturbance during the construction process within a minimum area from the development footprint.  Restore all disturbed or compacted soils that will be re-vegetated within the project’s development footprint.  Preserve the undisturbed greenfield area.  Use native or adaptive vegetation.  Increase the open space of the project beyond the d zoning(municipality or corporation) requirements. see also Q:25. Terminologies: Native Plants:Native plants are plants that have developed naturally in a geological location for many years. Adaptive Plants:Adaptive plants are not native for a particular geological location but can be adapted in the location without significant use of fertilizers, pesticides or irrigation requirements. Invasive plants:Invasive plants are not native for a particular geological location and require significant effort in maintaining them. Use of native or adaptive plants is a good practice in Green buildings. Invasive plants should always be avoided. Building footprint:Building footprint is the area of the project site used by the building structure, defined by the perimeter of the building plan. Landscape, access roads, parking lots and non-building facilities are excluded from the building foot print. Development footprint:Development foot print includes all the area affected because of the development of the building. It includes building GBA/GA V4/Rev 01 Page 4.8  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co footprint, hardscape, access roads, parking lots and non-building facilities within the project site area. Heat Island Effect: Heat island effect is the thermal gradient between urban and nearby rural areas. Heat island effect is discuss in detail under section 4.5. Open Space:Project site area- development footprint = Open Space Vegetated Roof can be counted for the credit calculation if the project satisfies the requirement for the credit Development Density & Community Connectivity. 4.4Rainwater Management: There are two criteria in this credit: Quantity Control– Controlling the velocity and volume of run-off from the project site. Quality Control– Controlling the pollutants and contaminants from the run-off. Intent: To reduce runoff volume Improve water quality by replicating the natural hydrology and water balance Significance:  In many cities storm water and sewage treatment are combined. Sewage treatment is an energy intensive process, when storm GBA/GA V4/Rev 01 Page 4.9  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co water mixes with sewage it overloads the sewage treatment plant and consume more energy.  Storm water run-off from hardscape areas, industrial areas, fertilized landscape etc., are rich in contaminants and hence pollutes receiving water streams.  Reducing storm water run-off helps maintain the natural aquifer recharge cycle.  Storm water run-off from fertilized land results in Eutrophication Fig 4.6Impact of development on storm water runoff Strategies:  Reduce impervious area and increase infiltration. Cluster developments to reduce paved surfaces such as roads and sidewalks.  Rainwater harvesting. Treated storm water can be used for irrigation and toilet flushing.  Use pervious paving materials.  Use vegetated roof, vegetated filter strips, bioswales, retention ponds. GBA/GA V4/Rev 01 Page 4.10  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Terminologies: Aquifer:An aquifer is underground water bearing permeable rock from where underground water can be extracted usefully. Impervious Surface:Surfaces that have less than 50% of perviousness and promotes storm water run-off instead of infiltrating into the sub- surface. Rain Gardens:A rain garden is a planted depression that allows rainwater run-off from impervious urban areas like roofs, driveways, walkways, parking lots, to be absorbed. Fig 4.7 A typical Rain Garden 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 run-off and sewage discharge). Xeriscaping : is the practice of designing landscapes to reduce or eliminate the need for irrigation. This means xeriscaped landscapes need little or no water beyond what the natural climate provides GBA/GA V4/Rev 01 Page 4.11  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Fig 4.8An indicative example for Eutrophication Vegetated Filter Strips:Vegetated filter strips (grassed filter strips, filter strips, and grassed filters) are vegetated surfaces that are designed to treat flow from adjacent surfaces. Filter strips function by slowing run- off velocities and filtering out sediment and other pollutants and by providing some infiltration into underlying soils. Retention Ponds/Sediment Basins:Retention ponds or sediment basins stores the storm water run-off temporarily and release it at very less velocity provide sufficient time for the sediments to settle down and storm water to infiltrate. Bioswales:Bioswales are landscape elements designed to remove silt and pollution from surface run-off water. They consist of a swaled drainage course with gently sloped sides (less than six percent) and filled with vegetation, compost and/or riprap. GBA/GA V4/Rev 01 Page 4.12  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Fig 4.9 Anindicative example ofBioswale Pervious Paving/Open Grid Paving:Pervious paving materials allow water to infiltrate as compared to impervious surfaces. There are variety of pervious paving materials available in the market. Fig 4.10 An indicative example of pervious paving Reference Standards:None 4.5Heat Island Reduction Intent: To minimize effects of microclimates on human and wildlife habitats by reducing heat islands. Significance:  Heat island effect is the thermal gradient between urban and nearby rural areas  Rural area experiences comparatively lesser temperature because of cooling effect evapotranspiration from plants. Whereas in urban areashardscape surfaces absorbs radiation, stores it and emit back to the atmosphere with a time delay. This contrast between urban and rural areas results in heat Island effect. Heat Island increases the temperature in urban area compared to the GBA/GA V4/Rev 01 Page 4.13  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co nearby rural area from 2 to 10o F. This increases the heat gain of the building resulting in a bigger HVAC equipment and higher energy consumption.  Increase in temperature because of heat island also affects the site habitat. Fig 4.11 Impact of Urban Heat Island Effect Strategies:  Reduce impervious surface area.  Use vegetated roof.  Use high SRI coating materials in impervious surfaces.  Provide underground parking to reduce the impervious area due to parking lot and drive ways.  Shade hardscape area with trees, canopies etc.  Use open grid pavement with at least 50% pervious. GBA/GA V4/Rev 01 Page 4.14  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Terminologies: Solar Reflectance or Albedo:Solar Reflectance or Albedo is the measure of ability of a surface to reflect solar radiation. Solar Reflective Index (SRI):Solar Reflective index is the measure of a materials ability to reject. Higher the SRI value, lower the heat island effect. SRI is calculated based on Reflectance (reflectance) and emittance(emissivity). For a material to have a higher SRI both reflectance and emittance should be high.The table below summarizes Reflectance, Emittance and their influence in SRI of typical Construction Materials SRI values for Solar Solar Infrared Emittance SRI Infrared Reflectance Temperatures 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 0.85 0.91 107 coats, 2 mils Source: Lawrence Berkeley National Laboratory Cool Roofing Materials Database. These values are reference only and are not for use as substitutes for actual manufacturer data 4.6Light Pollution Reduction Intent:  To increase night sky access, improve nighttime visibility, and reduce the consequences of development for wildlife and people. Significance:  Excess light comes at the cost of energy. GBA/GA V4/Rev 01 Page 4.15  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co  Light trespass may cause sleep deprivation or may block an evening view in one’s property.  Light clutter may cause accidents.  Light pollution disturbs nocturnal life of habitats.  Sky glow disturbs the night sky view for astronomers. Strategies:  Use timers, occupancy sensors and daylight sensors to switch off unnecessary lights.  Comply with the light trespass requirements of Illuminating Engineering Society and International Dark Sky Association (IES/IDA)  Control light trespass from transparent surfaces by proper positioning and selection of lighting fixture or automatically closing the transparent openings after specified time.  Use full cut-off fixtures in external lighting. Full cut-off fixtures reduce the chance of light to escape above the horizontal plane and hence reduces sky glow. Terminologies: Light Pollution:Light pollution is the alteration of light levels in the outdoor environment (from those present naturally) due to man-made sources of light. Light trespass:Light trespass occurs when unwanted light enters one’s property, for example, by shining over a neighbor’s fence. Light clutter:Light clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles GBA/GA V4/Rev 01 Page 4.16  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co (including those thatmay be intended to illuminate), and potentially cause accidents. Skyglow:Skyglow refers to the glow effect due to excess external light that can be seen over populated areas. Lighting Power Density:Lighting Power Density (LPD) is measured in w/sq.m or w/sq.ft. It is the measure of power input per unit floor area for lighting. Reference Standards: Illuminating Engineering Society and International Dark Sky Association (IES/IDA). 4.8YouTube Video References: Eutrophication Animation: http://youtu.be/6LAT1gLMPu4 Heat Island Effect & Cool Roofs: http://youtu.be/urbpBy_Z5lE Vegetated Roof/Green Roof: http://youtu.be/pp79mGpomf4 Light Pollution: http://youtu.be/UdIGJNVUwmE GBA/GA V4/Rev 01 Page 4.17  ©2011-15 Green Building Academy Chapter 4: Sustainable Sites www.greenbuildingacademy.co Summary We have addressed  Construction activity pollution prevention  Site assessment  Site development-protect or restore habitat  Open Space  Rainwater management  Heat island reduction  Light pollution reduction Have a Question in this chapter? Discuss in our forum GBA/GA V4/Rev 01 Page 4.18