When asked to design a house, it is assumed architects would rather start with a blank canvas than reinvent an existing structure. That’s especially true when the house is of no particular provenance—say, a bi-level production home near the end of its life cycle. Clients, too, often overlook the opportunities to piece together old and new.

An exception is Eric and J.J. Edstrom, who live in a wooded subdivision west of Milwaukee. After 10 years in their boxy 1970s-era home, the couple agreed that its 1,300 square feet was roomy enough for them and their young daughter, even if it was dull and dysfunctional. They wanted a modern, compact design, one that would salvage the building’s still-viable structural parts.

The couple enlisted Milwaukee-based Johnsen Schmaling Architects, who saw the project as a chance to experiment with using the foundation, perimeter walls, and plumbing stacks of an outmoded structure as the framework for a new one. Architects Brian Johnsen, AIA, and Sebastian Schmaling, AIA, thought of it as a clean box, if not a clean slate.

“We thought about how to bring in light, take advantage of views, and connect the house to the outside—all the things you’d do when designing from scratch,” Schmaling says. Reorganizing the interior added space and opened up the cellular floor plan, while three bigger moves judiciously accomplished the other goals. A new shed roof, supported by exposed metal and wood trusses, slopes up toward the north, inviting light deep into the interior through a long band of translucent, aerogel-filled polycarbonate glazing.

“Before the remodel, it was like a dungeon in here; now we don’t have to turn on any lights during the day,” Eric Edstrom says. “The roof design was an important eco-issue—how to use a translucent material across the front of the house without losing heating or cooling.”

Ferrous House, Spring Prairie, Wis.
John J. MaCaulay Ferrous House, Spring Prairie, Wis.

In fact, Schmaling says, the polycarbonate’s ?-inch aerogel cavity has an R-value of 7, compared to 2.6 to 3.5 for 1-inch-thick insulated low-E glazing. (Solutions such as these earned the home a 2010 AIA Housing Award, a recognition that is increasingly looking to honor ecological design.)

The facades are built for environmental performance. Walls with large windows were reframed using 2x6 studs, and the remaining walls were furred out to create a 5-inch cavity filled with spray-foam insulation. Attached to the sheathing is a VaproShield membrane that allows the house to breathe. A COR-TEN steel rainscreen, hung 1 inch from the membrane, wraps the house on three sides and eliminates heat and moisture buildup.

In these straitened times, Johnsen and Schmaling’s approach offers a sensible alternative to the default response of tearing down and building bigger. “We were probably more involved in construction than on a new home because of not knowing what we’d encounter,” Schmaling says. “But I don’t think it’s anything people should be afraid of.” He estimates the owners saved about 25% in construction costs by using the existing house’s bones.

“There’s a sense of pride when you know you’ve saved something you easily could have torn down,” he says. “You don’t have to start from scratch to create something of value and artistic integrity.” AIA