Framework

If your new home will have wood-frame construction, an insulation R-value of 19 or more is recommended.

The most effective way to achieve this level is to use 2x6 studs to frame the sidewalls . The added two inches of depth allows for a 5-1/2-inches of insulation (approx. R-19), instead of the 3-1/2-inches (approx. R-13) available with conventional 2x4 studs.

Upgrading to 2x6 construction costs about $1 more per square foot - but the difference will quickly be paid back in energy savings.

Two-by-six construction also provides greater noise reduction, because the additional insulation does a better job of muffling sound.

If you choose to stick with 2x4 construction, your builder should use rigid foam insulation to the interior. This material offers an insulating value of up to R-6; adding this to the 3& inches of between-the-studs insulation will bring the total R-value of the wall to the recommended R-19.

Many builders in the Midwest will add an inch of rigid foam insulation between the stud wall and the exterior sheathing. This outer layer prevents heat loss through the wall, and brings the total insulation value to R-24 with a 2x6 stud wall.

Alternative framing materials

Wood framing isn't the only option for building your new home. Several alternative methods are becoming more prevalent across the Midwest.

Unlike traditional wood construction, structural insulated panels use no wood studs in the construction process. These strong, super-insulated structural building components can be used for floors, walls and roof.

Steel-framed homes use steel studs for walls and roof trusses instead of traditional wood studs. Steel framing can be designed to meet or exceed energy efficiency standards. By using a 2x6 steel stud, the insulating value is R-36 - almost double the R-19 of traditional wood construction.

Learn more: PowerHouse "New Home Construction" Brochure [pdf] - By Alliant Energy