Builder Magazine - July 2008 - (Page 78)

DESIGN N Site Matters o conversation about green building can commence without a discussion about the site. “[It’s] mandatory, from where you put the building to how you handle stormwater,” says architect Bill Kreager, principal of Seattle-based Mithun Architects. “It’s critical.” Long after you’ve moved on, the site plan will affect home buyers, local wildlife, drinking water, and a host of other issues that many builders don’t even think about. The Austin, Texas–based Austin Energy Green Building program says in its Sustainability Source Book that the site should get ﬁrst consideration and be evaluated for all characteristics. It “has a crucial role in future performance of the building and enjoyment of occupants,” the group says. Here, then, are some site items to take into consideration.—N.F.M. PROMOTE WATER DRAINAGE The architects at the University of Arkansas Community Design Center say that up to 47 percent of surface pollutants such as fertilizers can be removed from a site in the ﬁrst 15 minutes of a storm event and drain into local waterways. This is not good because much of this rain (or melted snow) runs right into the stormwater system and some ends up in the drinking water. Using pervious surfaces is a better idea because it reduces runoff and manages the water on site. The illustration below shows how the Design Center employed a variety of pervious mechanisms for Habitat Trails, an eco-friendly project of 17 Habitat for Humanity homes in Rogers, Ark. ➊ Crushed stone provides a permeable surface, which helps ﬁlter stormwater. storage and recharge, which helps water reach the soil. ➍ Bioswales with facultative vegetation aid in pollutant removal. ➋ Porous asphalt aids in water ➎ Recycled pervious material Each person in the U.S. uses 80 to 100 gallons of waterU.S. Geological per day. Source: Survey ➌ Grasscrete permeable surface with facultative vegetation provides sediment control and recharge capacity. allows for water inﬁltration and is safer and better for play and pedestrian use. source: University of Arkansas Community Design Center ➍ ➊ Typical residential developments manage stormwater with “pipe-and-pond” systems that collect rainwater and discharge it off site. A low-impact designed (LID) site takes a different approach. Modeled after nature, “it manages rainfall on site,” a Massachusetts Metropolitan Area Planning Council low-impact development fact sheet says. “Designers should seek to maintain or create small sub-watersheds on the site KEEP A LID ON IT and ‘micromanage’ the runoff from these subwatersheds in small, decentralized structures such as swales, bioretention areas, inﬁltration structures, and ﬁlter strips.” Mithun Architects used a low-impact system for its 120-acre High Point development in Seattle and was able to reduce its pond area from the typical 5 acres to 1 acre. The plan cost $2.7 million, but it allowed 72 additional units, architect Bill Kreager explains. ➎ ➋ ➌ Low-ﬂow toilets can save Americans 1.2 trillion gallons of water andBuilding Museum nationwide every day. $11.3 million Source: National 78 ■ B U I LD E R j u ly 2008 W W W.BUILDERONLINE.COM http://WWW.BUILDERONLINE.COM

Table of Contents Feed for the Digital Edition of Builder Magazine - July 2008

Builder Magazine - July 2008 Contents Editor's Notes B-Mail Book It Green House Business Update Products National Beat Seider's Economy The Greener Good Commentary Land Planning Design Construction Marketing Ad Index Further Considerations Environmental Concerns Commentary Road to Perdition? Editor's Notes Flip Contents

Builder Magazine - July 2008

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