Our Homes Go Beyond “Energy Efficiency”
There are many factors to consider when building a high-performance home. Four key ingredients include:
- Siting the Home. To the extent possible, we site our homes to take advantage of natural heating and cooling—from the sun, prevailing breezes, etc. We also take care to calculate the appropriate amounts and locations of windows and any necessary shading, based on a host of variables. Considering these factors early in the design process is common sense and good building science.
- Insulation. We use a combination of renewable materials for insulating our wall and roof assemblies, and we engineer the insulation thickness to optimize cost and performance. While the actual insulation amounts will depend on the house location and style, we typically we use R-33 insulation in the walls and R-38 to R-49 in the ceilings. To complement the wall insulation, we use triple-glazed windows and well-insulated doors.
- Minimizing Thermal Bridging. Our wall assembly includes a layer of continuous insulation that helps to minimize “thermal bridging”—the transfer of heat via conduction from the warm side of the wall to the cold side. And we have engineered our wall to allow for drying to both the inside and out, essentially eliminating the possibility of damaging moisture within the walls.
- Air tightness. We build our homes tightly—and maintain indoor air quality through a continuous supply of fresh air—because air tightness is one of the keys to energy efficiency—in a typical home, more heat is lost through air movement (convection) than by other means. The energy and cost savings resulting from air tightness are essentially “free,” because building a tight home is more about careful workmanship than adding additional materials. By carefully taping every seam and putting gaskets at each joint, we typically achieve air tightness levels below one air change per hour (less than 1.0 ACH50). By comparison, the typical Energy Star rated house has about 3 air changes per hour, making it more than three times as leaky as a Unity Home!
Bottom line: You won’t need a conventional HVAC system. And with a moderately-sized renewable energy system, the home can produce as much energy as it uses, making it a Net Zero Energy Home.