The cottage represented a chance for Chicago architect John Eifler to “Wright” a few wrongs — such as scrap the forced air system that his preliminary energy study indicated couldn’t properly heat the home, and put in the radiant system Wright specified in the first place.

As Eifler recounts in his book, Frank Lloyd Wright’s Seth Peterson Cottage: Rescuing A Lost Masterwork, the project allowed him to finish what a great architect started. “Most restoration projects assume that the building will be returned to a representation of a certain period of time, usually when the building was in its ‘heyday’” Eifler writes. “Unfortunately, the cottage was never really completed during the lifetime of either the architect or client. Both Peterson and the second owners had finished the cottage with modifications, which were not in keeping with Wright’s intent.”

This “what might have been” approach also allowed Eifler to even improve on Wright’s design and make improvements in energy conservation — for example, increasing the roof insulation to 8 inches from just 2 inches, and using double-paned glass.

Choosing a heating system for the rehab, however, was one of the easiest decisions made. Wright was specifying radiant in-floor systems back in the 1930s. (See sidebar.) In order to install the radiant system at the cottage, volunteers from the Seth Peterson Cottage Conservancy mapped, photographed and numbered each flooring stone so it could be reinstalled in its exact position. The tubing and concrete slab rest atop an unusual insulation material — perlite, a volcanic mineral.

“We wanted to use natural materials as much as possible,” Eifler told us. “The perlite is fireproof, and has a R value similar to fiberglass batt insulation.” In addition, perlite’s insulation value does not decrease over time.

The creature comfort provided by radiant heat may be one reason the home is such a popular spot, regardless of the season. Instead of the hoped-for 36 percent occupancy rate that was needed to just break even, the cottage is occupied 325 days a year — and at $225 a night, with a two-night minimum stay strongly recommended! What’s more, many guests have returned as often as four times, and plan additional future visits.

“Historical buildings are usually operated by cash-poor, not-for-profit entities, but in the case of the cottage the board is now in the unique position of changing the color of the financial ink from red to black” Eifler says, whose company has restored dozens of Frank Lloyd Wright buildings around the country.

The extra cash ensures the upkeep of the cottage, and its popularity gives people a chance to live in a Frank Lloyd Wright home, if only for a few days. (Meanwhile, anyone with $2 can take a public tour of the site, which is held on the second Sunday of every month.)

Forgotten Work: The tiny cottage, just 850 sq. ft., was a forgotten work by one of the most influential architects of the 20th century, and hardly regarded as important compared to Wright’s other magnificent designs. The home, located along the shore of Mirror Lake, was barely lived in before being boarded up and left to the harsh elements for 25 years. (Midwesterners will know the location better as The Dells.)

But, Wright’s chief assistant, William Wesley Peters, claimed the structure contained “more architecture per square foot than any building Wright ever built.”

We took the public tour this summer, accompanied by Madison, WI, radiant contractor and Wright buff, Mike Ward. Although our pictures are dramatic, the sense of space really needs to be experienced first-hand to truly appreciate what Wright did. The hallmark of Wright’s design was to minimize structure to only that which is necessary to support a building. As Eifler notes, Wright deliberately challenged the laws of physics at times. That’s readily apparent from the way the roof seemingly appears to rest on a wall of glass. Seen from below, its sandstone-walled terrace and sloping roof give the impression of a much larger building.

Inside, while the cottage is essentially one big room, visitors hardly feel cramped, For example, the sloping roof rises from a cozy 6'8'' over the living room to 12' along the wall of glass that encloses the living room on three sides.

Wright designed the cottage for Seth Peterson, a lifelong lover of Wright’s architecture. Although Tailiesin, Wright’s Wisconsin estate, was just a half-hour drive from the cottage site, the architect never visited the location. He was 92 at the time and relied on topographic maps and photographs to get a feel for the terrain and the sun patterns. Wright died in 1959, a couple of months before construction on the cottage began.

Construction progressed throughout 1959. However, Peterson clearly ran into financial difficulty during the final stages. Not only did the builder file liens, but a number of changes in Wright’s original design were made to cut costs. Most notably for PM readers was replacing the in-floor radiant system with forced air. With the cottage essentially complete, Peterson committed suicide in 1960 just a few months short of his 24th birthday.

After Peterson’s death, the cottage sat empty for two years. Afterward, a Milwaukee resident purchased the home and lived in it until 1966, when the state of Wisconsin bought the property to be included into Mirror Lake State Park. The state basically just wanted the land and probably would have razed the cottage if it weren’t for the Wright design. State officials considered options for its use, but never could come to any conclusions. Not wanting to destroy a Wright home, park officials finally boarded it up, where it steadily deteriorated for the next 25 years.

In 1989 a group of local property owners, led by Audrey Laatsch, met with various state groups and began putting their heads together to figure how to restore the architectural gem. A vacation rental was one of the first options the group brainstormed. Laatsch and the other volunteers eventually formed the Seth Peterson Cottage Conservancy and set about raising money restore the cottage and turn it into a unique vacation rental.

The group clearly had its work cut out for itself. A quarter century of abandonment had left much of the original building beyond repair. The roof and framing would all have to be replaced. Water seepage had also essentially destroyed virtually all the original cabinetry, ceilings, and wood trim on the inside. The electrical, mechanical and plumbing systems, including the well and the septic tank, was either missing or destroyed. About the only original materials worth salvaging were the sandstone walls and fireplace, as well as some ornamental wood work around the windows that had been protected by the roof overhang.

The price tag was originally put at $250,000 — which eventually rose to $350,000 when everything was said and done. This figure also includes donated products as well. A local contractor, for example, donated a Burnham boiler. Heatway donated the radiant system and Kohler donated the fixtures in a current color that came the closest to approximating the “desert sand” color specified by Wright so many years ago. Even the radiant floor did its part — for $200 a donor could “sponsor” one of the flagstones that rests atop the radiant slab.