Sustainable Building Technical Manual - Etn-presco.net

CHAPTER 7Site Materials andEq u i p m e n tOutdoor construction and site modification rely on diverse materials: living plants andsoils, raw materials, and manufactured items. The careful selection of site materials is anessential part of environmentally conscious design. Selection variables to be consideredinclude toxicity in manufacture and use; energy consumption in extraction, manufacture,or transport; potential to intensify heat, glare, runoff, wind, or other climatic factors;and, in the case of plant materials, invasiveness, water consumption, and diseasesusceptibility.AuthorKim SorvigMaterial performance depends upon bio-regional characteristics: a plant or paving stonesuitable in Miami is unlikely to perform well in Anchorage or Albuquerque. Likewise,material selection must be specific to the proposed uses of the site: native grasses orporous asphalt may be ideal for low-traffic locations, but not for heavily used publicspaces. Specialized site knowledge is essential to making good choices, and early integrationof regionally appropriate, ecologically based principles can significantly enhanceproject success.Soils and Soil Amendments★ S I G N I F I CA N C E .Soil is an irreplaceable living resource that, once removed or killed, can take decades (insome regions millennia) to re-form. 1 While soil serves many mechanical purposes forconstruction, regarding it as inert invites problems—from mudslides and cracked foundationsto unhealthy landscape plantings. For these reasons, soil characteristics must berespected during design, and the soil itself protected during and after construction.Sustainable development avoids building on prime agricultural soils, and requires thaton each site enough undamaged, fertile soil remain after construction to support plantand wildlife diversity, infiltrate precipitation, and filter pollutants that cannot be controlledat their sources.