Sustainable Building Technical Manual - Etn-presco.net

. ☛ SUGGESTED PRACTICES AND CHECKLISTI❑ Include an ecologically knowledgeable landscape architect as an integral memberof the design team.❑ Preserve existing vegetation, especially native plants.– Design to avoid sprawl, which destroys native plant communities.– Use greenbelts and protected wetlands to create a continuous web of native habitats(also serving as bikeways and trails) through which animals can migrate safely.Many communities have greenbelt groups and ordinances, both valuable sourcesof advice and guidance.– Decrease parking, paving, and lawns to the minimum that will actually be used.– Make every space serve several functions; where possible, make the landscapes ofpublic or institutional buildings available to the local community, rather than fencingthem off.– Avoid “replacing” healthy mature trees with small nursery stock.❑ Protect existing plants during construction (Figure 1).Delineate and fence the “dripline” (area directly under the canopy) of all trees.Prohibit parking, stockpiling, heavy-equipment movement, or excessive foot traffic infenced plant-protection zones within driplines; enforce with a liquidated-damagesclause.❑ Design new plantings as diverse communities of species well-adapted to the site.Use primarily native species: they usually require less maintenance and less water thanexotics after establishment (one or more seasons). Do not, however, expect “no-maintenance”landscapes. Reserve exotics for accents. Avoid use of any plant that is invasive:such species overrun native ecosystems. Avoid monocultures (plants of all onespecies or age), and use plants which attract desirable wildlife.❑ Follow Xeriscape principles.A trademarked term referring to water-efficient choices in planting and irrigationdesign. The seven basic Xeriscape principles for conserving water and protecting theenvironment are: planning and design, use of well-adapted plants, soil and climateanalysis, practical, reduced turf areas, use of mulches, appropriate maintenance, andefficient irrigation by grouping plants with similar water needs. Coordinate plantingswith water harvesting systems. 6❑ Use plants to mitigate climate conditions.Deciduous plants, when correctly located, provide shade in summer and admit sunwhen their leaves fall for winter, a natural technique for passive solar design.Evergreen trees can provide year-round sun and wind protection (see Chapter 11,“Renewable Energy”). Windbreak plantings diminish wind within a distance threetimes their height. To decrease noise significantly, a wide (200-foot) band of plantingsis required.❑ Use a reputable nursery or contractor to supply and install plants.Do not accept wild-dug plants, which may be endangered, and whose removal impoverishesother landscapes. Specify plants grown in the same U.S. Department ofAgriculture (USDA) Hardiness Zone as the site, preferably within a 200-mile radius.Seed or seedlings may be cost-effective for mass planting, and tend to develop goodhardiness. The planting contract should require the contractor to plant during the correctseason (which varies by species), and to maintain all plantings through at leastone full growing season after planting, with a warranty to replace any plant that dieswithin that time.❑ Employ integrated pest management (IPM) against insects and weeds.IPM uses biological controls as a first defense; if such non-toxic controls fail, carefullytimed and targeted pesticides are used. Biological controls include parasitic insects,which destroy pests; pheromone (sex-scent) traps; natural pesticides like pyrethrum;and companion-planting. Artificial pesticides should be chemically targeted to a nar-