Several groups have teamed up in Louisiana to show the various shades of green construction. The "Going Up, Going Green" project is building three homes side by side that will earn bronze, silver, and gold status respectively under the National Green Building Standards championed by the NAHB. As one goes up the scale, home construction gets more complicated. For instance, the silver-level house (shown here) features a 2x10 floor system framed at 24 inches on center. That earn points for efficient lumber use. The wall system supplements OSB sheeting with a half inch of foam insulation. There's a radiant heat barrier on the roof decking, a more efficient heat pump, a tankless water heater, and a better grade of low-e glass. This being Louisiana, all the homes were built above flood level and can resist hurricane-force winds. www.woodencreationshomes.com/going-up-going-green.html