Design for space efficiency. Yes, home size is client-driven. But bear in mind that larger homes require more natural resources to build and maintain, as well as more energy to light, heat, and cool. Under LEED for Homes, houses that are larger than the national average (based on the number of bedrooms) must earn more points to achieve the same level of certification as smaller homes. Though it may sound challenging, the beauty of a national standard is that it allows the suburban trophy homeowner and the urban apartment dweller to have a discourse about sustainable living relative to the same scale.air control
Design for energy efficiency. Most green home standards require energy performance equivalent to those standards set forth by the U.S. Environmental Protection Agency's Energy Star homes program, and LEED for Homes is no exception. Architects can earn LEED credits based on a Home Energy Rating System (HERS) Index that outperforms the minimum required for Energy Star. Or they can follow a prescriptive path to meet and exceed criteria for insulation R-value and installation quality; window U-values and solar heat-gain coefficients; heating, cooling, and hot water equipment efficiencies; lighting and appliances; and so on. Architects should become particularly familiar with the new Energy Star Thermal Bypass Inspection Checklist, which requires (among other things) that all insulation be in full contact with an air barrier on six sides. This affects typical design details such as dropped ceilings, window seats, and bathtubs and staircases on exterior walls. A local Energy Star provider can supply a full explanation of the checklist requirements, which can be found at www.energystar.gov.
Design for health. Indoor environmental quality receives a significant amount of attention (and therefore points) in LEED for Homes. Proper whole-house ventilation, localized exhaust, supply rates of conditioned air, separation of garages, and a host of other issues are either required or strongly recommended for superior occupant health and comfort. Low-VOC, no-formaldehyde alternatives for insulation, paints and coatings, and floor coverings add to LEED point totals at low or no added cost. For more information on healthy building practices, search online for the Energy Star Indoor Air Package (IAP) specifications. GreenSpec and similar resources include a host of options for healthier materials selection.
These strategies for achieving durability, efficiency, and health are by and large invisible in a completed green home, but they represent the most significant, cost-effective steps toward achieving success under LEED for Homes. Architects interested in designing to meet the pilot program criteria can visit the USGBC Web site (www.usgbc.org) to contact a LEED for Homes Provider for more details or to enroll a project in the pilot program.
Steven Winter, FAIA, is the current chair of the U.S. Green Building Council's LEED for Homes Committee and the president of Steven Winter Associates, a building systems consultancy with offices in Norwalk, Conn., Washington, D.C., and New York City.