Recently, the American National Standards Institute (ANSI) approved the National Green Building Standard, making the green home building certification program the first in the industry with the weight of standards approval behind it. Proponents of the voluntary standard say it is the new industry benchmark for green homes. The National Association of Home Builders (NAHB) has adopted the new standard as the basis of its National Green Building Program, "NAHB Green."

A joint project of the NAHB and the International Code Council (ICC), the National Green Building Standard—also known as ICC 700-2008 NGBS—addresses all forms of residential construction, including single-family and multifamily new construction, remodeling and additions, and subdivision development. Each type offers four certification levels: Bronze, Silver, Gold, and Emerald. Builders can elect a prescription-based path, choosing from a menu of options, or a performance-based path, demonstrating a home's performance above a threshold, for the first three certification levels; achieving Emerald certification requires a performance-based path.

Not only is the standard comprehensive in terms of housing type, it also takes a comprehensive, holistic approach to green building, addressing every aspect from lot design to owner education. The ANSI-approved standard awards points for:

  • Lot design, preparation, and development
  • Resource efficiency
  • Energy efficiency
  • Water efficiency
  • Indoor environmental quality
  • Operation, maintenance, and building owner education.

    "It's a rigorous, yet flexible standard," said Mike Luzier, president of the NAHB Research Center (NAHB RC), in a Feb. 5 press teleconference about the standard. Each certification level requires a set of mandatory criteria to be met, but beyond these minimum requirements builders have the flexibility to choose how they will achieve the necessary points remaining, according to the needs of their customers or specific market.

    Each point a builder claims toward certification must be confirmed by an independent inspector certified by the NAHB RC, which acts as the third-party certifying body for National Green Building Certification. A minimum of two evaluations must be performed during the building process: once during the rough-in stage and once at or near completion. "Once verification is complete, the paperwork is submitted electronically to the NAHB RC, the application is reviewed and checked, and then certification is issued," Luzier said.

    The More You Know

    Homeowner education—something many green building programs don't address and that builders commonly don't consider—is an important aspect of the standard, says Kevin Morrow, NAHB's program manager for green building standards. "How homeowners live in [their homes], their behaviors in terms of water and energy usage, the appliances they use, the HVAC settings they use, whether they're using the systems the builder installed will have the greatest impact of all on how high-performing the home is," he says.

    The standard is designed to work within the safety requirements of the International Residential Code (IRC), and according to Dominic Sims, chief operating officer of the ICC, it's the only green building program to do so. "We have been able to remove any potential barriers that building, fire, and safety codes might present to green efforts. The consistency and coordination built into the standard [are] key to its performance," Sims said during the teleconference.

    NGBS' base certification fee for NAHB nonmembers is $500; members get a $300 discount. However, as NAHB RC points out, each building company will have to negotiate evaluation charges with its accredited verifier.

    How They Stack Up

    It's inevitable that the NGBS will be compared to the U.S. Green Building Council's (USGBC) LEED for Homes certification program. The NAHB and many of its members have argued that the requirements to achieve LEED-H certification are too rigorous and the process too costly, while others in the industry see the LEED-H program as the gold standard for green home building. A broad cross-section of industry stakeholders, including the USGBC, were asked to participate in the standard's development in an open, consensus-based process "The fact that the USGBC had a voice in the creation of this standard will take the wind out of a lot of conjecture" and comparisons between LEED-H and the NGBS, Morrow says. "The early reports we've seen and preliminary studies show that in terms of stringency, [the programs] are very similar."

    Whether the NGBS will appeal more to production builders than to custom home builders, whose clients may view LEED-H as the prestige program, remains to be seen. There are advantages for each. "The fact that it's a flexible program makes it work well for custom builders; the fact that it's nationally applicable makes it work well for production builders. It was written for both groups in mind," Morrow says.

    "It's an enormous step forward in the housing market," adds ICC's Sims, "because it represents the first green building standard that is safe, that is sustainable, and that also provides an affordable solution in an important segment of the construction industry: the new housing market."

    For more details on the NAHBGreen program and the new National Green Building Standard, visit www.nahbgreen.org.