Our Homes Are Way Beyond “Energy Efficient”.
There are four factors to consider when building an energy-efficient home:
- The first step is to site the house so it receives as much solar gain as possible. The next step is to calculate the proper glazing area and appropriate shading based on a host of variables. Making these decisions first is both common sense and good science.
- For insulating, we look for the “sweet spot” between cost and performance. Typically we use R-35 insulation in the walls and R-38 to R-48 in the ceiling, depending on the climate and style of house. Plus we use triple-glazed, low-emission windows and our own insulated doors.
- We use wood as our structural material, which is far better than steel or concrete at minimizing thermal bridging. The I-joist framing member not only has the ability to carry heavier loads with less lumber, but the web of the i-joist further reduces thermal bridging.
- Air tightness is an important focus because it’s one of the most important keys to energy efficiency and is essentially “free,” since it has more to do with good workmanship than more “stuff.” By carefully taping every seam, and putting gaskets at each joint, we typically achieve air tightness in the range of .5 to .7 ACH @50Pa (air changes per hour, at 50 Pascals). By comparison, the typical Energy Star rated house in America is 3-6 ACH@50 Pa, in other words, up to 12 times as much!
Bottom line: You won’t even need a conventional HVAC system. And with minimal renewable energy you can be completely off the grid.