by Michael J. Crosbie, PhD, AIA

Summary: The greening of American housing is due to bloom later this year, when the U.S. Green Building Council rolls out its “LEED® for Homes” program. It’s been a while in the making. Unlike commercial buildings, which have benefited from a national LEED standard since the late 1990s, green standards for housing have followed a “let a thousand flowers bloom” philosophy. There are now more than 70 green housing programs around the country. LEED for Homes will offer architects a comprehensive standard and guidance for creating sustainable abodes.

What will LEED for Homes cover? The program includes eight different categories:

• Innovation and Design Process
• Location and Linkage
• Sustainable Sites
• Water Efficiency
• Energy and Atmosphere
• Materials and Resources
• Indoor Environmental Quality
• Awareness and Education.

Similar to LEED for New Construction, LEED for Homes has four performance tiers based on the number of points earned. In this case, size really does matter. The larger the house, the more it requires in materials to construct and other resources to 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. The point threshold will be adjusted based on house size. For an average-size home, the thresholds are 45 for Certified; 60 for Silver; 75 for Gold; 90 for Platinum.

LEED for Homes has four performance tiers based on the number of points earned

As the categories above suggest, a sustainable home is the product of a comprehensive, “whole building” approach to design and construction. It even includes what happens to the home after it is occupied—that’s where the homeowner comes in. LEED for Homes requires that residents receive a detailed instruction manual and training on green aspects of their new homes. All the great green technologies in the world won’t make a bit of difference if they’re not properly maintained and operated.

Whole buildings approach reigns
The comprehensive nature of LEED for Homes is also evidence that it is not a “bells and whistles” approach to sustainable design and construction, which is what usually grabs public attention in the general press. For example, one of the most important keys to creating a sustainable home is durability. Proper detailing and construction of such elements as flashing, drainage, and pest resistance help to extend the life of materials and systems, which is directly tied to getting the most out of resources already expended to build a house. Extending the life of a building is one of the best approaches to making it green. LEED for Homes will require durability and quality management planning for all homes.

This is not sexy stuff, but it’s where the rubber meets the road in terms of sustainability

Other aspects of sound sustainable design and construction promoted by LEED for Homes relate to enhancing the performance of the house’s thermal envelope. In this case, many of the green strategies such as better levels of insulation and other thermal barriers are hidden from view. This is not sexy stuff, but it’s where the rubber meets the road in terms of sustainability.

Also for multifamily
LEED-H also promises to provide green guidance for the design of mid-rise multifamily buildings. Right now, a project underway in Brooklyn, N.Y., designed by Dattner Architects and being built by Habitat for Humanity—New York City, is being constructed to LEED for Homes standards. Comprising three four-story buildings totaling 41 units, the Atlantic Avenue Apartments will provide a core and exterior enclosure within which volunteers, future residents, and a Habitat professional construction team will create individual apartments. Among the green strategies being employed are drought-resistant landscaping, rapidly renewable and low-emitting products and finishes, unitized ventilation so that bad air from other units does not circulate through the entire building (promoting good indoor-air quality), the use of hollow-core plank floors to exhaust air, and make-up air introduced by “trickle vents.” Our firm modeled the design’s performance to understand how the building would perform before it was built.

The lessons learned at Atlantic Avenue should help mid-rise multifamily buildings to find a green niche between single-family houses and multifamily high-rises.