Last Updated: May 27, 2021
The Wisconsin shore of Lake Superior has been home - literally for Pete Brownlee's grandmother, and as a family gathering place for the Brownlee clan—for generations. In the 1970s, the adventurous, extended family built a geodesic dome on the lake to use as the family cabin. More recently, Pete and his wife Ann bought the lot next door, which had stairs down to the lake (the lot with the geodesic dome doesn't).
"We were interested in the lot," explains Ann Brownlee, "for the lake access and initially didn't intend to build on it. But the day we closed on the property, Pete and I went to lunch, looked across the table from each other, and said, 'Let's build a cabin.'"
The couple lives in Stillwater, Minnesota, in a Victorian farmhouse with solar panels powering much of the electricity. "My husband worked in construction, and we've always tried to be environmentally conscious and sought to reduce our footprint. At the cabin, I wanted something different aesthetically but with the smallest footprint possible."
The couple worked with architect Rosemary McMonigal of McMonigal Architects in Minneapolis. They built a 1,500-square-foot cabin for family and friends using SIPs (structural insulated panels) and T-mass (thermomass) as construction methods. "We went with super-insulated construction," Brownlee says. "It was a no brainer for us. We all need to do everything we can, in new construction, to lower our impact and save money."
"Most of our clients come to us wanting sustainability and a small house," says McMonigal. "We get people focused on energy who like to monitor how their homes perform. Our clients are also usually willing to try different systems like SIPs and T-mass. For me, those clients make designing energy-efficient sustainable homes more interesting, and it allows us to test new products and systems to learn what performs the best."
McMonigal adds that she's a "long-time fan of SIPs," a panelized system that sandwiches a layer of insulation between two pieces of plywood or oriented strand board (OSB). "We did our first project with SIPs about 25 years ago," she says. "Back then, we had the SIPs fabricated in Canada because that country was about five years ahead of the US. We found that the speed with which we could build was so fast. It's a great system with insulation and structure all in one."
McMonigal based the cabin's design on a four-foot module, "so we wouldn't have wasted plywood or paneling. It became a rhythm we used as we laid out the house. It was also efficient from a construction standpoint. Sustainability includes wasting less material." She used SIPs for the roof and walls, with plywood on the outside and a higher grade of plywood left exposed on the interior.
"The Brownlees liked the idea of honesty in structure," she adds. "The higher-grade plywood also gives the rustic interior a bit more finish." The roof SIPs have large overhangs that direct water away from the house, and control sun and shade.
The frame walls, at R-37, and the roof panels, at R-43, didn't require any additional insulation. The cabin sits on a slab-on-grade, thermal mass building insulation system (R-17), with continuous insulation in the wall's core.
"Not everyone wants concrete on the inside, but it's a good system for a foundation in this climate, where the snowdrifts up higher than one foot," McMonigal says. The concrete wall also creates a wind buffer, shields the home from adjacent road-noise, and "has a visual interest that they like."
They sourced windows that bring in plentiful natural daylight from a local manufacturer, H Windows, in Ashland, Wisconsin, just 30 miles from the cabin. The 100-year-old company, originally based in Norway, set up shop in Monticello, Minnesota, before relocating to Ashland to be closer to the wood they use, McMonigal says. "They also felt there was a larger pool of potential employees in the Ashland area that would welcome detail-oriented factory work."
"We used a triple-glazed window, after spending time examining the combinations of glazing to use on the different layers," McMonigal says. "We have a few windows to the North, and more toward the South and the lake to take advantage of the fantastic views." The operable windows also provide cross-ventilation, eliminating the need for air conditioning. Alternating shed roofs add ceiling height and bring daylight deep into the house.
The team clad the cabin's exterior in brown cedar siding and gray concrete, to blend into the wooded site by reflecting the color palette of the tree trunks and rock outcroppings. The metal roof changes with the light, taking on characteristics of the sky. Wood walkways float above the ground, leaving the forest floor undisturbed. The use of concrete at floors and walls, exposed laminated veneer beams, and vertical steel rods at the stairs contribute to the interior's spare, rugged quality.
The all-electric cabin has all LED lighting, a heated concrete floor, and a wood-burning stove that quickly heats the cabin. "We intentionally picked materials with zero-added formaldehyde, including in the panel products for the cabinets," says McMonigal. All of the interior finishes are low-VOC. "That was a huge deal," she says. "They were concerned about indoor air quality."
The couple also bought shares in a local solar farm. "We bought panels to invest in the community, but they're not at the house," Brownlee explains. "They provided us with a formula to reduce our electrical bill. We were told we'd receive payback from our investment in about 20 years, but it'll be more like within 10 or 12 years. It's very cool."
One of Brownlee's favorite aspects of the cabin is how McMonigal managed to insert three bedrooms, but just one bathroom. "She made it work by separating out the shower, toilet, and sink with sliding doors," she says. "So even with a full house, with ten people or more, people can wind their way through the bathroom area with tying up the entire space. It's very efficient."
The cabin also includes a bunk room and a sauna. "It's a gathering place," Brownlee says. "People feel comfortable staying here. It has a great vibe, with everything you need in a clean, comfortable, and cozy space, so it's always in use."
How do Ann and Pete feel about their cabin?
“It's pretty darn perfect. I can't believe how much we love this place.”
Camille LeFevre is an architecture and design writer based in the Twin Cities.