A sculptural, wood-burning, board-formed concrete fireplace, built by Mike Gohman of W. Gohman Construction, designed to reference Breuer’s Abbey Bell Tower at Saint John's, anchors the living space. Family friend and Saint John's University potter Richard Bresnahan hand-crafted the clay bricks in the firebox.

Interior designer Sheree A. Vincent, Certified Green AP, founder of Fusion Designed in Forest Lake, MN, guided the couple in their interior sustainability selections. "Sustainability is the foundation of my design practice," Vincent says. "As a couple, Debbie and Steve are in tune with the environment and want to protect it any way they can. Colin works within a sustainable practice. It was a great collaboration between all the parties."

The unique timber-framed home was built using wood from Blue Ox Timbers in Alexandria, Minnesota. The home features a shou sugi ban (charred cypress) exterior (with Douglas fir accents), a sustainable, pest-resistant, and maintenance-free material. While the charred wood came from Japan, Vincent explains, the siding won't need any upkeep for at least 80 years. Throughout the home's construction, she adds, sustainable strategies were incorporated.

Debbie concedes that she and Steve "weren't exactly downsizing with the house, and we used a lot of wood in the building of the timber frame. But the house is all on one level. The bedrooms are small. And we have a big family and want them to stay." The team incorporated in terms of sustainability, one could argue, far outweighs Debbie's concerns about the framing (using timber from sustainably managed forests) and the size. Here's why.

Debating Geothermal

In Avon, electricity is expensive. Natural gas isn't an option. Nor did Debbie want propane, with unsightly tanks outside the house. While deciding on a system to heat and cool the home, the Koop's were reluctant to install closed-loop geothermal. One reason was the expense. "They expressed that they would most likely never realize the financial payback because of their age," Vincent recalls. "My response was that payback, maybe, wasn't the major reason for deciding to do it—that creating a legacy for the future was perhaps the guiding factor."

The Koop's were convinced. They also realized several benefits. "We were required to buy 40 acres to build, and we wanted to restore the prairie in front, so we put the geothermal system underneath the prairie," Debbie explains. "We learned that the geothermal would pay for itself faster than if we were to use electricity. And now that we're using geothermal for heating and cooling, we love it. It reaches every area of the house."

"Sustainability, good indoor air quality, and land stewardship were all a part of the decision-making process," says Vincent. "I can't emphasize enough how comfortable we all are with the decisions made."

Kitchen and Bathroom Cabinetry

The Koops selected European-style Puustelli MIINUS cabinetry for the kitchen and bathrooms. Puustelli frames are made of a bio-composite material that contains zero formaldehyde. The cabinets are MDF and chipboard free, incorporate formaldehyde-free glues, and are not made from endangered wood species. They are also recyclable. In manufacturing the cabinets, the company uses 50 percent fewer materials.