Back to nature: wind and sun power a Midwest retreat

Custom Home, July-August, 2005 by Meghan Drueding

When Oregon, Ill., builder Rick McCanse first encountered his future clients Kent and Kathy Lawrence, it didn't take him long to decide he wanted to work with them. "I knew we'd get along famously," he says. Not only did their laid-back personalities mesh well with his, but they also shared his concern for the environment. The Chicago couple had set up their own 55-acre nature conservancy on their land in Oregon, about 90 miles west of the Windy City. And they'd hired appropriately named architect Thorn Greene to design a weekend house, one that would demonstrate the benefits of green building.

McCanse and his family live in an eco-friendly passive solar home he built in 1979 using salvaged lumber and other recycled materials. So his experience dovetailed nicely with Greene's passive solar design for the Lawrences' house, known as the Kickapoo Dwelling after the American Indians who once inhabited the area. The plan's major passive solar feature is a long, glass-walled hallway along the home's southern edge. Sunlight streams in through the glass and hits an 8 1/2-inch-thick stone wall, a thermal mass that holds the heat and radiates it throughout the day and night. The architect angled the home's standing-seam metal roof and exterior trellis to protect the hall from excess sun during summer while still letting in the lower winter sun. The glass wall's operable upper and lower windows work with the clerestories atop the stone wall for cross-ventilation.

In addition to passive solar, the Lawrences also wanted to incorporate some active energy-producing technologies. They commissioned an engineering study that looked at the costs and payback rates of heat pumps, solar hot water heaters, photovoltaic panels, and wind power, all tailored to their particular site and climate. "The directions we gave for the study were, if something doesn't get you your capital investment back within 15 years, it's out," says Kent Lawrence. "If it doesn't work economically, it's not going to be a good demonstration." The heat pump and solar hot water heater didn't pass the test, but the wind power and photovoltaics did. Greene's design incorporates both, and if the study's predictions are correct the combination of wind and active solar provides the home with 56 percent of its energy needs. This time the architect's own experience came in handy--his off-the-grid vacation cabin in Michigan runs on photovoltaics. (For more on the wind turbine and photovoltaic panels at the Kickapoo Dwelling, see "Blowing in the Wind," page 99.)

The study also estimated that the home's passive solar design would generate 20 percent of its heat. For the remainder, Greene specified a standard HVAC system with a gas furnace and central air conditioning (both Energy Star rated) as well as a small amount of radiant heat. The system is divided into four zones for maximum energy efficiency. An air-to-air heat exchanger helps keep warm, fresh air circulating, and an electronic air cleaner filters out particles that aggravate Kent's allergies. Low-E, argon-gas-filled windows form a tight seal against untreated outside air. The couple has never set their thermostat higher than 60 degrees throughout the punishing prairie winter, and they rarely turn on their air conditioning. "It's about 72 degrees all the time inside," says Kathy.

The home's sustainable status owes just as much to green materials as it does to energy-saving systems. It's filled with recycled, salvaged, and low- or no-toxicity products, many of them found by Greene through the subscription-only product information service GreenSpec (see "Mining for Green," page 98). McCanse also got involved in product hunting, contributing reclaimed cypress from his own stockpile and trolling his local lumberyard, Black Hawk Lumber, for reclaimed and sustainably harvested wood. "They were just wonderful at helping me track things down," he says. He especially admired the long-lasting character of the Trex composite decking used outside, as well as the aesthetic appeal of interior items like wheatboard and Marmoleum surfaces, bamboo floors, and low-VOC paints. "They behaved like a good latex paint," he says of the latter. "Even the darker colors covered in two coats."

McCanse mixed blown-in cellulose insulation with a water-based glue in the upper walls and basement ceiling, where it needed extra stabilization. "The glue forms a crest so the recycled cardboard sticks in place" he says. A no-VOC drywall compound at first annoyed his subcontractors, who found it too sticky to work with. But they discovered that mixing several ounces of Joy dishwashing liquid into a 5-gallon bucket of the stuff improved its consistency--a cheap and effective solution.

Such simple innovations mix seamlessly with the home's complex patchwork of alternative systems. "The interior is technology married with architecture and craftsmanship and detail," Greene says. The house itself makes up just a part of the Lawrences' ambitious plan to create a model of ecological stewardship. They've opened the house for tours several times, and they're working on re-naturalizing the land with native plants and grasses. The couple hopes to make Kickapoo their primary residence at some point, and McCanse understands why. "I've had more passion and excitement for this house than anything I've ever built," he says.--M.D.