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Sustainable Siting
Perhaps the greatest impact to the environment when constructing a building occurs upon selection of the site. Thus, the site selection process or site-planning phase may well be the most important step to reduce or minimize the overall environmental damage of the project. With this in mind, proper care should be taken to screen potential sites before purchasing and optimize the selection process for all criteria including environmental. This can be achieved by including the entire interdisciplinary design team during the site selection process. ENVIROMENTAL DESIGN ISSUE Perhaps the greatest impact to the environment when constructing a building occurs upon selection of the site. Thus, the site selection process or site-planning phase may well be the most important step to reduce or minimize the overall environmental damage of the project. With this in mind, proper care should be taken to screen potential sites before purchasing and optimize the selection process for all criteria including environmental. This can be achieved by including the entire interdisciplinary design team during the site selection process. ENVIROMENTAL DESIGN ELEMENT The purpose of collecting data is to identify the assets and liabilities of each site. Each of the potential sites should be assessed in a similar manner. ENVIROMENTAL DESIGN ISSUE Perhaps the greatest impact to the environment when constructing a building occurs upon selection of the site. Thus, the site selection process or site-planning phase may well be the most important step to reduce or minimize the overall environmental damage of the project. With this in mind, proper care should be taken to screen potential sites before purchasing and optimize the selection process for all criteria including environmental. This can be achieved by including the entire interdisciplinary design team during the site selection process. ENVIROMENTAL DESIGN ELEMENT The purpose of collecting data is to identify the assets and liabilities of each site. Each of the potential sites should be assessed in a similar manner. ENVIROMENTAL DESIGN ELEMENT For each potential site, analyze impacts of proposed design. Identify alternative designs for each site that mitigate site-specific impacts. Utilize the entire design team to compare the assets and liabilities of each site. Evaluate and decide based on all criteria, environmental, social, and economic. ENVIROMENTAL DESIGN ISSUE issue content ENVIROMENTAL DESIGN ELEMENT It is important to avoid choosing and developing virgin landscapes. ENVIROMENTAL DESIGN ELEMENT Whether to increase density or to avoid further damaging suburban land, it is a prudent choice to select land that has already had some form of human development upon it before tearing up new land on the city’s boundaries. ENVIROMENTAL DESIGN ELEMENT Locate your building on a site where ample sunlight is available. Know where the sun rises and sets in order to capitalize on natural lighting. ENVIROMENTAL DESIGN ELEMENT Site the building to take into account available public transportation for employees and guests. Provide preferred parking stalls for car pool vehicles and easy security for bicycles with change and shower facilities in house. By locating nearby public transportation corridors, the designer may be able to decrease the size of parking lot, and provide a better working environment for the staff. Proximity to recreational corridors or pathways is also an asset for guest recreation. ENVIROMENTAL DESIGN ISSUE Once the optimum site has been selected, it is essential to minimize development impacts to the site. Restrict disturbance to within 10 metres away from the building. Site selection should have identified likely disturbances to each site as one criterion for the selection process. Any areas that are damaged should be restored after construction. Minimising the footprint of a building will often minimise the environmental impacts on the site related to construction. This should be a target for the design team. ENVIROMENTAL DESIGN ELEMENT Controlling erosion and excess sediment produced during the construction phase is paramount to avoiding environmental impacts on water and air quality especially in areas where heavy precipitation is common. ENVIROMENTAL DESIGN ELEMENT It is important to limit the disruption of natural water flows through the site. This can be achieved by minimizing storm water runoff, increasing infiltration, and reducing the amount of contaminants available to pollute the water. ENVIROMENTAL DESIGN ELEMENT Although not readily apparent, the soil plays an integral role in mitigating surface impacts of storm water runoff and the success of vegetation growth and overall landscaping of the site. Protecting the soil is of most concern during the design and construction phase. ENVIROMENTAL DESIGN ELEMENT The existing vegetation should be viewed as an asset to enhance design (i.e. natural shading, reduced landscape construction and maintenance) and reduce impacts of the development (i.e. reduced storm water runoff, increased infiltration). ENVIROMENTAL DESIGN ISSUE issue content ENVIROMENTAL DESIGN ELEMENT A heat island is the result of a surface that has absorbed solar radiation during daylight hours which then gives off heat to the adjacent air. Since dense materials like concrete and asphalt have greater thermal capacities than adjacent (natural vegetation cover) surfaces, they can store more energy from the sun and thus become hotter surfaces. This heat is distributed to the air whenever the surface slab is hotter than the air. This occurs after mid-morning until potentially late into the evening. ENVIROMENTAL DESIGN ELEMENT Anytime impervious surfaces are applied to a site, impacts occur due to reduced vegetation, increased runoff, and increased solar heating. Careful attention must be paid to the alteration of the site water cycle that impervious paving may cause. ENVIROMENTAL DESIGN ELEMENT Allowing occupants to utilize the outdoor space surrounding the building enhances the connection between architecture and nature.
Before a site is chosen, a number of sites should be assessed to see whether they are compatible with the entire design teams goals and priorities (see First Things First). The assessment should include collecting and assessing a variety of data. Questions need to be addressed such as will the building have access to sunlight (one of the greatest resources of a site)? Is the site virgin natural landscape which should be left intact in preference for developing a brownfield or urban site? Does the location have sufficient access to efficient public transportation? Can the land be effectively developed while controlling excess sediment and erosion? Will the development increase stormwater runoff? Can the existing soil be maintained intact or transplanted? Is the existing native vegetation (if any) a barrier to the project or can it be maintained? Can any further landscape development reduce the effect of heat islands? Does the site allow for minimum impervious surfaces to be employed while giving preference to pervious surfaces? Do outdoor public amenities exist?
Many other questions need to be asked before selecting a site and thus taking the time to form a complete design team complete with goals and priorities is paramount when attempting to reduce environmental impacts related to siting of a building.
Selecting an Appropriate Site
Before a site is chosen, a number of sites should be assessed to see whether they are compatible with the entire design teams goals and priorities (see First Things First). The assessment should include collecting and assessing a variety of data. Questions need to be addressed such as will the building have access to sunlight (one of the greatest resources of a site)? Is the site virgin natural landscape which should be left intact in preference for developing a brownfield or urban site? Does the location have sufficient access to efficient public transportation? Can the land be effectively developed while controlling excess sediment and erosion? Will the development increase stormwater runoff? Can the existing soil be maintained intact or transplanted? Is the existing native vegetation (if any) a barrier to the project or can it be maintained? Can any further landscape development reduce the effect of heat islands? Does the site allow for minimum impervious surfaces to be employed while giving preference to pervious surfaces? Do outdoor public amenities exist?
Many other questions need to be asked before selecting a site and thus taking the time to form a complete design team complete with goals and priorities is paramount when attempting to reduce environmental impacts related to siting of a building.
Once the interdisciplinary design team has been assembled, the potential sites must be scrutinized to find the optimal combination of site features that will allow for the least impact to the site and surroundings. The first step is to collect all the relevant data from each proposed site. Then a comparison can be made between sites and the optimal location will present itself. There are a variety of criteria that should be considered when deciding on a site to develop. Avoid selecting inappropriate sites and always attempt to minimize any environmental impacts that may occur from the development.
Collecting Data
Analyze all the proposed sites to determine site characteristics that will influence building design. Study how the solar altitude, microclimate, and the topography will affect design (i.e. solar orientation, wind loading, floor elevations, potential for passive solar/daylighting)
Consider the climatic zone of the site. Each climatic zone (cold, temperate, hot-dry, hot-humid) have design strategies to maximize the overall design (i.e. passive solar vs. shading, deciduous vs. coniferous vegetation).
Perform soil and groundwater testing. Avoid building on soils that are contaminated with agricultural or industrial chemical residues. Establishing a clean source of groundwater is important if the building is to be self-sufficient. contaminated groundwater is a likely indication of nearby pollution that may impact the building operation environmentally and economically.
Test soil suitability for bearing strength, additional slope structures, and infiltration. Test the native soil for bearing, compaction, and infiltration capacity. Assess the added cost of importing fill to the site to make the soil suitable for development.
Evaluate ecosystems for existence of wetlands and endangered species. Assess and identify any areas that may not suit building development or require special preservation or restoration.
Examine existing vegetation to inventory significant plant populations. Denote vegetation that may require special protection during construction. Identify species and populations such that the landscape designers can later mitigate any damaged areas with original elements.
Avoid stream channels, flood plains, wetlands, steep erodible slopes, and mature vegetation. Evaluate whether the interstitial spaces (i.e. between channels, plains, etc.) are enough for the proposed building footprint.
Map all natural hazard potentials. Disclude the site if there is evidence of significant past disturbances (i.e. 100-year flood level, slopes prone to slides, wind-damage, avalanche potential). Consider discluding a site if it is within the 100-year flood level (many jurisdictions provide or require the purchase of flood insurance for development within the 500-year flood level).
Diagram existing pedestrian and vehicular movement and parking to identify patterns. Determine whether existing patterns fit the proposed design plan. Take advantage of existing patterns to reduce environmental impacts and infrastructure costs, or consider a different site.
Review the potential of utilizing existing local transportation resources. Attempt to share existing infrastructure (i.e. parking facilities, shuttle buses) with neighbouring developments to reduce overall costs and increase site efficiency.
Analyse site for existing utility and transportation infrastructure and capacity. Identify any need for increased capacity or upgrades and denote costs (the need for additional infrastructure may discount the site). Examine potential of integration with building design.
Identify any construction restraints and requirements that the site necessitates.
Observe the architectural style of the area. Attempt to incorporate some elements of the community’s architectural fabric in the design of the building and landscape (i.e. materials, colours). Utilize historically compatible building types where appropriate.
Review site’s cultural resources for possible restoration. Discuss the potential of including existing resources within the building plan and design.
Analyze the site’s existing air quality. Determine the existing outdoor air quality and analyze how the proposed building will affect air quality. Observe diurnal wind patterns and investigate potential ventilation intake/outtake orientations and locations.
Selecting an Appropriate Site
Before a site is chosen, a number of sites should be assessed to see whether they are compatible with the entire design teams goals and priorities (see First Things First). The assessment should include collecting and assessing a variety of data. Questions need to be addressed such as will the building have access to sunlight (one of the greatest resources of a site)? Is the site virgin natural landscape which should be left intact in preference for developing a brownfield or urban site? Does the location have sufficient access to efficient public transportation? Can the land be effectively developed while controlling excess sediment and erosion? Will the development increase stormwater runoff? Can the existing soil be maintained intact or transplanted? Is the existing native vegetation (if any) a barrier to the project or can it be maintained? Can any further landscape development reduce the effect of heat islands? Does the site allow for minimum impervious surfaces to be employed while giving preference to pervious surfaces? Do outdoor public amenities exist?
Many other questions need to be asked before selecting a site and thus taking the time to form a complete design team complete with goals and priorities is paramount when attempting to reduce environmental impacts related to siting of a building.
Once the interdisciplinary design team has been assembled, the potential sites must be scrutinized to find the optimal combination of site features that will allow for the least impact to the site and surroundings. The first step is to collect all the relevant data from each proposed site. Then a comparison can be made between sites and the optimal location will present itself. There are a variety of criteria that should be considered when deciding on a site to develop. Avoid selecting inappropriate sites and always attempt to minimize any environmental impacts that may occur from the development.
Collecting Data
Analyze all the proposed sites to determine site characteristics that will influence building design. Study how the solar altitude, microclimate, and the topography will affect design (i.e. solar orientation, wind loading, floor elevations, potential for passive solar/daylighting)
Consider the climatic zone of the site. Each climatic zone (cold, temperate, hot-dry, hot-humid) have design strategies to maximize the overall design (i.e. passive solar vs. shading, deciduous vs. coniferous vegetation).
Perform soil and groundwater testing. Avoid building on soils that are contaminated with agricultural or industrial chemical residues. Establishing a clean source of groundwater is important if the building is to be self-sufficient. contaminated groundwater is a likely indication of nearby pollution that may impact the building operation environmentally and economically.
Test soil suitability for bearing strength, additional slope structures, and infiltration. Test the native soil for bearing, compaction, and infiltration capacity. Assess the added cost of importing fill to the site to make the soil suitable for development.
Evaluate ecosystems for existence of wetlands and endangered species. Assess and identify any areas that may not suit building development or require special preservation or restoration.
Examine existing vegetation to inventory significant plant populations. Denote vegetation that may require special protection during construction. Identify species and populations such that the landscape designers can later mitigate any damaged areas with original elements.
Avoid stream channels, flood plains, wetlands, steep erodible slopes, and mature vegetation. Evaluate whether the interstitial spaces (i.e. between channels, plains, etc.) are enough for the proposed building footprint.
Map all natural hazard potentials. Disclude the site if there is evidence of significant past disturbances (i.e. 100-year flood level, slopes prone to slides, wind-damage, avalanche potential). Consider discluding a site if it is within the 100-year flood level (many jurisdictions provide or require the purchase of flood insurance for development within the 500-year flood level).
Diagram existing pedestrian and vehicular movement and parking to identify patterns. Determine whether existing patterns fit the proposed design plan. Take advantage of existing patterns to reduce environmental impacts and infrastructure costs, or consider a different site.
Review the potential of utilizing existing local transportation resources. Attempt to share existing infrastructure (i.e. parking facilities, shuttle buses) with neighbouring developments to reduce overall costs and increase site efficiency.
Analyse site for existing utility and transportation infrastructure and capacity. Identify any need for increased capacity or upgrades and denote costs (the need for additional infrastructure may discount the site). Examine potential of integration with building design.
Identify any construction restraints and requirements that the site necessitates.
Observe the architectural style of the area. Attempt to incorporate some elements of the community’s architectural fabric in the design of the building and landscape (i.e. materials, colours). Utilize historically compatible building types where appropriate.
Review site’s cultural resources for possible restoration. Discuss the potential of including existing resources within the building plan and design.
Analyze the site’s existing air quality. Determine the existing outdoor air quality and analyze how the proposed building will affect air quality. Observe diurnal wind patterns and investigate potential ventilation intake/outtake orientations and locations.
Assessing Data
Identify topographic and hydrological impacts of proposed design. Note potential mitigation measures required or alter design.
Develop general area takeoff and overall building footprint compatibility with site. Design the building for the site not vice versa.
Identify alternative site design concepts to minimise resource costs and disruption. Remain flexible to take advantage of all site assets in the design.
Review financial implications of site development, building, and projected maintenance costs. Accounting for all life-cycle costs leads to an optimum choice.
Develop matrix of use and site compatibility index. Use the matrix to easily identify key assets and liabilities of each site.
Evaluate project site selection, based on all criteria.
Site Selection Criteria
Avoidance of Virgin or Signifcant Land
Brownfield/Urban Redevelopment
During the selection process, give preference to urban redevelopment sites and sites that have previously been damaged environmentally.
Select urban sites that can be redeveloped. Avoid developing virgin land whenever possible to minimize habitat destruction.
Select brownfield or previously damaged sites when mitigation strategies can be implemented. Investigate potential economic incentives and land improvement funding available. Avoid sites that have unrepairable damage.
Encourage in-fill and mixed-use development. Development that mixes residential and commercial space decreases the need for automobiles.
Access to Sunlight
Access to Alternative/Public Transportation
Support reduction of vehicle miles travelled. Support and design for ease of use of mass-transit. Reduce parking capacity and encourage car-pooling. Consider facilities (i.e. showers, locks) for cyclists.
Identify and use existing vehicular transportation networks to minimize the need for new infrastructure. Reduces construction, operating, and maintenance costs. Reduces non-permeable surfaces.
Consider increased use of telecommuting strategies. Evaluate the cost benefits including deferred building components, operations, and maintenance.
Consolidate service, pedestrian, and automobile paths. Thereby reducing paving area, centralizing runoff, and increasing efficiency of paths.
Reducing Site Disturbance
Sediment and Erosion Control
Develop a plan for both the construction phase and the operation phase. Utilise silt fencing and sediment traps, phase construction accordingly, stabilise steep slopes, and maintain vegetated ground cover.
Stormwater Management
Soil and Soil Ammendments
Involve a qualified site-design professional on the design team early in the project.
Obtain and evaluate the chemical and physical characteristics of the site soils.
Amend the soil in planting areas according to professional advice.
Protect the soil during construction. Design for minimal grading. Stockpile and replace existing topsoil when grading is necessary. Avoid the movement of heavy equipment over site. Remediate compacted soil after construction with tillage, etc.
Carefully design for grading and excavation. Design building with site in mind. Utilize sites strengths (i.e. existing topography, drainage patterns) and direct storm water to planted areas to minimize irrigation requirements.
Follow all applicable erosion-control regulations. Avoid exposed soil and mitigate potential erosion where necessary and/or required by regulations.
Stabilize soil during and after construction. Utilize natural means where possible (i.e. straw bail dams, jute netting, hydroseeding).
Use bioengineering. Interwoven woody cuttings reduce the potential for full-scale washouts more common to rigid constructions.
Instruct operators to schedule soil-maintenance tasks. To be done in conjunction with other planting and site vegetation maintenance activities.
Vegetation and Grounds Management
Include an ecologically knowledgeable landscape architect as an integral member of the design team.
Preserve existing vegetation, especially native plants. Avoid fencing off property where possible to make landscape available to community increasing project integration. Decrease paving and monoculture lawns. Avoid replacing mature trees with young seedlings.
Protect existing plants during construction. Delineate the “drip line” around trees and demark or fence off areas to avoid damage. Contain heavy equipment and stockpiling areas to predefined areas.
Design new plantings as diverse communities of species well adapted to the site. Plant native or drought resistant species (less maintenance and water) of varying ages. Select vegetation that attracts wildlife. Avoid invasive species and monocultures (same species, same age).
Follow XeriscapeTM (water-efficient) principles.
Use vegetation to mitigate climate and existing site conditions. Deciduous trees provide shade during summer and allow solar gains in winter. Coniferous trees provide year round shade and wind protection (wind protection = a distance 3 times tree height). Noise mitigation requires at least a 75-metre band of vegetation.
Hire a reputable nursery or contractor to supply and install plants. This avoids contractors that pilfer plants and plant out of season.
Employ integrated pest management (IPM) against insects and weeds. Avoid synthetic chemical pest management (pesticides, herbicides, insecticides, biocides, etc.) in preference for natural, organic products.
Use mulching, alternative mowing, and composting to maintain vegetation health. Avoid synthetic fertilizers. Recommend manual-push mowers rather than powered types. Design for and utilize on site composting for landscape nutrient supplementation.
Compile and follow a seasonal maintenance task list. Regular maintenance is key to maintaining a healthy landscape.
Site's Impact on Design
Landscape Design to Reduce Heat Islands
Conventional buildings typically have dark coloured roofs and are surrounded by asphalt or roadways. The black (low albedo or good heat absorption capabilities) thermal mass coupled with the clearing of trees on a site (reducing shade) increases ambient temperatures. This can be beneficial for cold-climate buildings (passive solar gains) but costly in temperate to hot climates (increased cooling loads).
Harness solar energy, airflow patterns, natural water sources, and the insulating quality of landforms for building temperature control. Waterbodies are effective heat sinks (in cold-climates as winter heat sources, in hot-climates as air-cooling). Landforms can also play an important role consider colour and orientation.
Use existing vegetation to moderate weather conditions and provide protection for native wildlife. Green space not only forms necessary connections between parcels of habitat, but also provides shade and the cooling aspects of transpiration.
Design access roads, landscaping, and ancillary structures to channel wind toward main buildings for cooling, or away from them to reduce heat loss.
Pervious and Impervious Surfaces
Limit paving areas to the strict minimum for their intended purpose. Specify smaller parking stalls (i.e. 2.8m by 5.6m rather than 3m by 6m).
Carefully distinguish between light-vehicular, heavy-vehicular, and pedestrian paving. Avoid using vehicular paving when not needed. Specify alternative materials (permeable interlocking block, gravel: See Water-permeable or Porous Paving below) rather than non-renewable, energy intensive pavement.
Use water-permeable or “porous” paving. By removing the fine elements of concrete and asphalt, water is allowed to percolate into the soil. Select porous paving or alternatives (i.e. block-lattices, masonry pavers on sand).
Design paving to serve dual purposes. For example, placing a parking lot over top of a gravel reservoir designed to handle stormwater volumes.
Design to minimize runoff. Curbs focus runoff, increasing water volume and erosion capability. Designing for infiltration of runoff as close to source (subterranean gutters, curbless roadways) is most cost effective.
For light-duty roads and paths, stabilize without pavement. Crushed stone or brick (potentially reclaimed from old building) can be an effective porous road surface.
Locate pavement where solar heat gain is desirable. Be aware that dark coloured pavement absorbs and slowly releases large amounts of solar heat (beneficial in cold climates) and light coloured pavement can introduce severe glare on sunny days (but minimizes solar heating).
Outdoor Public Amenities
A well-designed building takes advantage of the site to provide shaded areas for eating and relaxation, connecting corridors between buildings, and easy, safe access routes to adjacent buildings on neighbouring properties. All executed in a manner as to retain the original vegetation communities intact.
Modify microclimates to maximize human comfort in the use of outdoor public amenities such as plazas, sitting areas, and rest areas. Regulate sun and wind and be conscious of seasonal variation in weather.
Consider sustainable site materials for public amenities. Specify recycled or reclaimed materials with low life cycle costs. Consider surface albedo to avoid severe glare.
Specify sustainable site construction methods. Avoid unnecessary site disruption.
Develop sequential staging to minimize site disruption.