With an ultra-efficient insulation package, the Michigan home’s 6.1 kW solar array will generate enough electricity for a family of four.
With an ultra-efficient insulation package, the Michigan home’s 6.1 kW solar array will generate enough electricity for a family of four.

A new Midland, Mich., demonstration home aims to prove to visitors from around the world that net-zero-energy living is attainable at an affordable price. Built by Freeland, Mich.-based Cobblestone Homes in partnership with Dow Building Solutions, the solar-powered InVision Zero Home, which has applied for LEED-Platinum certification, will save $2,441 in energy costs annually and generate as much power as it consumes, the partners claim.

Cobblestone Homes co-owner Melissa Wahl focused on tightly sealing and insulating the building envelope to dramatically reduce the home’s energy requirements.

“The No. 1 thing about building an affordable net-zero home is not how much solar or wind power you can throw at the project, it’s all about insulating and air sealing first,” she says. Through several rounds of energy modeling using REM/Rate software, she also discovered the importance of limiting and controlling the location of conditioned space in order to keep the energy load down.

For example, project planners opted to build a 4-foot-high conditioned crawlspace under the house instead of a traditional basement. “This way we have less air to heat and cool,” she says. The space holds mechanical systems such as the geothermal heat pump and air exchanger and also provides room for storage. Eight-foot-high ceilings also reduce the conditioned square footage.

To help keep the house affordable to mainstream buyers, Wahl looked for low-cost alternatives to high-end finishes and amenities, such as  fiberglass shower surroundsinstead of tile. The home is valued at $250,000 including the lot, slightly above the average price of a traditionally built home in the area, but it features greatly reduced energy bills, if any at all, Wahl points out.

“We did a careful cost analysis to make sure we were providing homeowners the performance they’re looking for at reasonable cost,” she says.

The project relies on many products and technologies from Michigan-based Dow, including Styrofoam  structural insulated sheathing (SIS), insulating foam sealants and weather barriers, and the company’s new Powerhouse solar shingles.

Other high-performance products include a Waterfurnace geothermal ground source heat pump, Superior Walls pre-cast concrete foundation, a Venmar ERV, and Energy Star-qualified appliances from Whirlpool.

The 1,556-square-foot home will serve as an educational center for the next year, providing tours, training, and hands-on demonstrations. A monitoring dashboard will be on display to track the home’s carbon footprint and energy usage. Response to the project, which has hosted guests from around the world since opening in early May, shows growing consumer interest in affordable energy-conscious homes.

“They are hungry for knowledge about how to achieve more comfortable and more energy efficient and durable homes that will last,” says Wahl.

Jennifer Goodman is Senior Editor Online for EcoHome.