In architecture, biophilia is more than plants scattered about the house. Biophilic design also incorporates natural materials, natural light, expansive views to the outdoors and nature, outdoor living rooms, and even responsiveness to and simulation of natural features found at the site.

 When this couple began the design process for their wooded site with dramatic lake views in Chenequa, Wisconsin, they had clear intentions. "We spoke only with architects whose work demonstrated organic design principles," they say. In 2007, they found Robert Harvey Oshatz, whose firm is based in Portland, Oregon. They were instantly intrigued by the dynamic forms of Oshatz's work and how he integrated those forms with the homes' surrounding environments.

Reflecting the Poetry of the Site  

"We told Robert we wanted to save the trees on the property," recall the homeowners. "He proposed a flowing form curving in-between the trees." Adds Oshatz, "We essentially wound the structure between the existing trees, giving the home a circular form that begins on the inside and works its way out to the exterior." 

Siting for Sun and Shade  

How do you heat and cool a 7500-square-foot house with so much glass? First, Oshtaz specified Heat Mirror glass, which is similar to triple glazing "and is Low-E, argon-filled, and has a U value," he says. Siting the home was also a factor.

"One problem we had in terms of glass is that the major view is to the lake, which is north," he explains, "so I sited the kitchen on the east side so it would get sunlight in the morning at a low angle. On the south side, which is at the back of the house, we put glass protected by large overhangs that shade the house in the summer. On the west, the glass provides views of the lake looking northwest, which is shaded by trees in the summer. In the winter, we have the west sun coming in in the afternoon, and in the summer, deciduous trees block the sun."

More glass also could have meant higher energy loss and less room for ductwork. But the team found the perfect solution. 

Electric Zoning Systems and Geothermal  

The team selected Mitsubishi VRF zoning systems. The company engineered this system to respond to inverter-driven technology and state-of-the-art heat recovery by responding to minute-by-minute changes in cooling and heating requirements or load. By varying the refrigerant flow to individual zones, the family could enjoy cooling and heating as necessary in a house designed to bring the outdoors in.

The homeowners control the system remotely using their smartphones. The system is also whisper-quiet. "From the beginning, one of our requirements was a quiet system," they say. 

The team paired the water-source heat pumps with a GeoExchange vertical closed-loop geothermal field for cooling and heating. The geothermal vertical closed-loop system uses the ground as a heat sink, as soil temperatures remain relatively constant at 55 degrees Fahrenheit. The system's compressor raises that temperature to a usable range in the winter, and the underground heat is pumped indoors. In summer, the process is reversed, with indoor heat pumped underground. 

Why geothermal? "We analyzed the site with the State of Wisconsin and considered solar and wind power," Oshatz says. "At the time, the State was recommending against wind power in this area. They suggested that, because of the trees, solar wouldn't work either. As we designed and built the home, we realized solar would work in the future. We wired the house for solar, which the clients may add to the geothermal in the future. For them, geothermal was the most environmentally sensitive solution and the most respectful to the site."

Despite the home's size, the lower level is devoted to the children, with a large family room, shared bedrooms, one bathroom, and a play area. "They thought in terms of the children learning to cooperate and share," Oshatz explains.