“It's less about materials and more about how it sits on the site,” Weesner said of the house.
On sunny days in the fall, winter and spring, sunlight illuminating the main living area of the home will heat its polished-concrete flooring.
In the summer, when the sun is highest in the sky for a longer period, most of its direct light will be blocked by a trellis. There will be times when this “passive” heating and cooling – and the currents of air flowing through ventilation in the home – won't keep people comfortable. On those days, he said, “minisplit” heat pumps will heat or cool the house.
The house also will also use some of the state-of-the art features used a century ago, from ceiling fans to skylights and vent windows that can be used to create cooling (or warming) flows of air through the house. Weesner estimated that heating and cooling the 4-bedroom, roughly 1,400 square feet home will cost only 10 to 20 percent as much as in a typical home that size.
It also will have energy-efficient appliances and be lit entirely by LED lights, so that it will need less electricity, he said.
A key part of the home's efficiency will be its insulation. It's heavily insulated with a spray-on foam that hardens quickly, similar to the expanding foam a homeowner can buy for weatherstripping cracks. The foam was donated by Dow Chemical Co.; Momper Insulation is donating the labor to apply the foam.
Every wall is insulated with two inches of foam on the inside and four inches of insulating board on the outside. The ceilings are insulated with four inches on the inside and four inches on the roof.
“It helps to fill all the voids so air doesn't move (through the walls),” Weesner said. “Air movement is as big a problem as low R-value.”
Matt Momper, president of Momper Insulation, said he's donating labor to this project because the techniques used here may inspire builders to provide more options for their customers, too.
“It's good for our community, and it helps the building industry,” Momper said.
Weesner expects the home will be finished and move-in ready sometime in February.
For more on this house
You can find photos, design drawings, plans and background information on this sustainable Habitat for Humanity House at www.projectinfill.com.