But, as Swaback acknowledges, those architects who worked under Wright are aging, and building codes and material continue to change. The foundation, he says, reviews its policies to ensure that Frank Lloyd Wright designs keep up with contemporary standards without interfering with "the clarity of the Frank Lloyd Wright heritage."

Massaro has hired Thomas A. Heinz, 50, of Libertyville, Ill., as architect of record to complete the house based on Wright's preliminary design. Heinz isn't affiliated with Taliesin but has written books on Wright and Greene & Greene, and built exact replicas of Wright's furniture designs.

During a visit to the site last fall, the weather was less than ideal for a boat ride to Petre Island. Still, the day was temperate compared with the conditions throughout the frigid early months of 2004 when Massaro and a revolving crew of about 25 workers made multiple shuttles between shore and island.

To solve the problem of transporting the materials across water, Massaro suggested waiting until the lake froze solid. Those trips took place not by boat, but in three John Deere Gator tractors, driven across the frozen lake as if it were a stretch of icy interstate highway -- hauling tons of concrete, sand and gravel on round-bottomed makeshift sleds, fashioned of oil tanks cut in half lengthwise.

Hand-pouring the concrete for the 2-foot-thick cantilevered floor took 36 hours and a revolving crew of about 80 people, says the project's general contractor, Lidia Wusatowska-Leghpon. Including the portion of the cantilever that is above land, employing only one support, the total length is 87 feet.

Over the years, Wright's Fallingwater's concrete cantilevers have proved notoriously troublesome, developing substantial cracks and tension stress that has necessitated several major reconstructions. For the Massaro house, more modern post-tensioning techniques will be used to prevent such problems.

The house, which the Massaros plan to use as a summer retreat, will include modern updates such as energy-efficient windows and better insulation and roofing than were available in the 1950s. But per Wright's design, the home will have small bedrooms and bathrooms. Closets will be a bit larger than was typical in the early 1950s, but might be considered inadequate to modern tastes.

Heinz, who has devoted much of his life's work to Wright, believes he is as capable as any Taliesin architect of seeing that work of art realized. "What Joe told me he wanted was the house that Frank Lloyd Wright would have done," Heinz said. "He is not so concerned about official or unofficial, he just wanted what Frank Lloyd Wright intended. Joe is a contractor, and contractors are always, I feel, like the cowboys -- 'Let's go.' "

The only deliberate design change that Massaro is making in the main house is to include three stained-glass windows that his wife designed. He has already installed one in the guest house, glowing red, green and yellow in the chaos of the construction.

"I really didn't have to worry about it until they gave me the building permit; I walked away saying, 'My God, I really have to do this now.' I mean, when do you get an opportunity like this in your lifetime?" Massaro says.

"If I'd gotten all the permits right away, I wouldn't have had the money to build it," he added. "It was like Frank Lloyd Wright was there, pushing me all the way."