This 1,340 square-foot single-story, south-facing rural home was built for a professional couple in western Washington in 2018. It features an additional 576-square-foot attached garage to the north. The unheated garage, which sits outside the SIPs shell, is stick framed to reduce building and energy costs.

The home’s two offices are permitted as legal bedrooms, so it’s really a three-bedroom, two-bath net-zero rambler with a huge south-facing roof that has space for enough solar panels to power two electric cars and run the house.

Specifications

  • Department of Energy Net-Zero certified
  • Fujistu 9RL minisplit heat pump
  • 100% on-site storm water infiltration via 40-foot dispersion trench
  • 70 trees and 160 shrubs were planted that will grow a forest on site
  • 10.8 kW of solar panels installed
  • 6.5” R-29 SIPs walls
  • 10.25” R-49 SIPs roof
  • 4” R-20 foam under 4” concrete slab-on-grade for thermal mass
  • 5.5” foam (total) R-23.8 insulated concrete form perimeter stem walls
  • Vinylek Boreal series triple-pane windows (U values of 0.14 to 0.16)
  • 1:1.6 aspect ratio floor plan, with the long side facing south
  • Minimal east and west glazing