Last Updated: Aug 17, 2021
As a young Wisconsin couple continued to grow their family, they recognized the need for a home that wouldn't merely meet and support their family's needs. The couple was also determined to build a dream home that reflected their values, including sustainability and respect for the natural environment. Moreover, they wanted a home that reflected their love of organic forms, natural materials, and a strong connection between the indoors and outdoors.
In today's parlance, one might say they had a propensity for biophilic design. The word "biophilia" was popularized in 1984 by Harvard biologist Edward Wilson, in his book of the same name. In "Biophilia," Wilson suggested that humans have a natural proclivity for seeking out deep connections to nature.
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.
"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."
"Basically, the home is three stories, with a three-level atrium or cylinder at the center," Oshatz explains. "The staircase wraps around and cantilevers out from the stone cylinder, which is also an elevator. The floors, which wind their way out from the central cylinder, were placed to take advantage of the lake views, how sunlight enters the home, and the curvatures reflecting the way you wind between the trees."
"When Robert asked us about textures and colors, we said we like natural materials in their original colors like stone and wood," the homeowners add. "He said he would work with our palette. To our eyes, he seemed to let the forms of the house dictate the materials."
Adds Oshatz, "Every site has its own poetry. We wanted to relate the structure and the materials to the poetry of the site." They chose natural stone inside and out, interior soffits of hemlock (to help the interior remain light and airy), concrete floors stained an earthy rust color, and on the exterior stucco that highlights the edges of the floor planes and defines the upper floor volume, and cedar fascia.
Throughout the home, floor-to-ceiling glass or glazing brings the outside in and provides dramatic views of the woods and lake. By removing the structure from the glazing line, by carefully continuing exterior materials inside right through the window walls, and creating the spiral shape, Oshatz designed a home without any directional emphasis. As a result, the family enjoys connections to the outdoors in every direction. The house, in turn, celebrates the forest and the lake.
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.
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."
The house was completed in 2011, and the couple and their four children happily moved in. "We've been in the house for nine years, and we feel we got exactly what we wanted. From the beginning, Robert said the structure should adapt to how we want to live, not us adapting to it, and it does."
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.
As for the family, they love their sustainable home. "We're constantly delighted by little discoveries we make every day in the house," they say, "but mainly, we appreciate the comfortable feeling we have being in the house. This goes with what Robert said when we interviewed him: that "the structure should be at peace with its environment, and we should be at peace within it."
Camille LeFevre is an architecture and design writer based in the Twin Cities.