Net Zero Energy Homes Part #4

The Amaris Company wall system starts with the DOW Structural Insulated Sheathing product on the entire exterior which provides an R5.5 insulation factor and a complete exterior air and moisture barrier. Because the DOW SIS wraps the entire exterior there is no wood to wood connections to the inside of the house and therefore no thermal bridging. Thermal bridging is when cold air conducts through wall studs and sheathing were no insulation is installed. You may have seen vertical lines on the sides of houses when driving through your subdivision in winter.
In our standard green homes, Amaris Company sprays 3" of closed cell insulation providing an R-21 insulation factor. The closed cell insulation also provides a complete air barrier. Air provides and "R" value of 5.0 when it is not moving. Because the DOW SIS and closed cell insulation provide superior insulation factors and air penetration barriers, we do not believe it is necessary to fill the entire 2 x 6 wall cavity.

Ceiling insulation is very important. Building code in Minnesota requires R-38 in our area. The Amaris Company system includes 1" closed cell insulation (R-7) over the ceiling deck and then cellulose insulation to an R-60. The closed cell insulation provides a complete air barrier.

Insulated foundations is also very important. We insulate the foundation walls and floor to an R-20.