Builders and their green living standards have come under discussion in recent weeks, as a recent Department of Energy report indicated that residential building consume 21.9 percent of the nation's energy and produce 21 percent of our greenhouse gas emissions.

Late last week the discussion in Congress circled around policies that mandate energy savings.

Matt Belcher, who testified on behalf of the NAHB, said, "The ability of aggressive building code mandates to achieve massive energy and greenhouse gas emissions savings is incredibly limited. The wide-ranging geographic differences in state and local climates create specific building needs, making national benchmarks almost untenable."

Policies that "encourage rather than mandate ... are the most meaningful" noted Belcher.

The House Subcommittee on Energy and Air Quality says, however, that the "key step in improving energy and air quality will be making America's buildings more efficient. The energy they consume accounts for 40 percent of total U.S. greenhouse gas emissions. Some experts believe that it would be possible to apply affordable solutions to reduce CO2 emissions attributable to the nation's buildings by more than 60 to 80 percent by 2050, suggesting that achieving those efficiencies will be a key ingredient of our overall greenhouse gas reduction strategy."