It's no secret that the U.S. Green Building Council's rating system, popularly known as LEED (for Leadership in Energy and Environmental Design), has become the predominant green standard for commercial buildings: 1,090 new construction projects have been certified.
Last month, ProSales focused on the Resource Efficiency section from the NAHB's National Green Building Standard. This month, we look at the comparable chapter from LEED for Homes, Materials and Resources.
Both rating systems carry the same core messages: optimize material usage, use environmentally preferable products, and minimize waste. Both may mean fewer lumber sales, but give dealers the opportunity to stock green products, offer green services, and become more involved in the green building process.
LEED's Materials and Resources section is shorter than the NAHB's equivalent chapter and counts for fewer overall points. Also, while the NAHB touches on issues such as life-cycle assessment in its section, LEED's does not. Michelle Moore, senior vice president of public affairs at USGBC, says LEED is moving to include life-cycle assessment. More information will be out later this year.
NAHB is more flexible on a touchy subject for dealers: certified wood. It gives points if builders use wood certified by one of several groups, while LEED only recognizes wood certified by the Forest Stewardship Council. However, Moore says a committee is considering letting certified wood from other groups–particularly those woods sanctioned by the Sustainable Forestry Initiative–count as well. A draft of this credit will be available for public comment later this year.
To become certified in LEED for Homes, a builder must earn at least 45 points by completing 18 prerequisites and suggested practices. A minimum of two points must come from the Materials and Resources section, which has three parts: material-efficient framing, environmentally preferable products, and waste management. Each part has prerequisites as well as opportunities to earn additional points.
Builders can get up to five points in the material-efficient framing section. The NAHB's standard also covered this topic. In the LEED standard, builders must first limit "the percentage of framing material ordered in excess of the estimated material needed for construction" to 10% or less.
Builders can earn one point by providing a "detailed cut list and lumber order" before construction that "corresponds directly to the framing plans." The NAHB also rewards detailed plans and materials lists.
These requirements provide an opportunity for dealers to help builders plan projects and keep them from overstocking material.
Recommended in the NAHB's standards as well, builders in LEED can get up to three points for using prefabricated components, such as open-web floor trusses. Or builders can earn up to four points by using panelized construction for preframed wall, roof, and floor components.
The environmentally preferable products section awards half a point for each qualifying product, with a maximum of eight points.
A table in the section notes specific requirements, but generally, products count if a material makes up 90% of a component by weight or volume. For example, if 90% of siding or masonry contains recycled content or is FSC-certified, half a point is awarded for that component.
Except as noted in the table, recycled content products must contain at least 25% post-consumer recycled content, 50% for post-industrial recycled content.
Products with low emissions, as listed in the table, also qualify. "Healthy indoor air quality and low- and no-VOC products are the easiest things people can do," Moore says.
Locally produced products that were "extracted, processed, and manufactured within 500 miles of the home" also count toward points.
In the waste management area, builders must look at local options for diverting waste, such as recycling or reusing material. Builders must also "document the diversion rate for construction waste."
Builders can gain up to three points if they generate 2.5 pounds or less of net waste, not including diverted waste. Or, builders can divert 25% or more of the "total materials taken off the construction site" from going into landfills and incinerators.
Like the NAHB's standards, dealers can use this section to work with builders and see what waste could be returned to yards. "Waste reduction is one of the biggest success stories with LEED," Moore says.