It was Elizabeth Duncan who wanted a house designed by Frank Lloyd Wright; her husband, Don, thought he was an architect for the rich.

But then they saw an article in the December 1956 edition of House and Home magazine on Wright's affordable, prefab houses for Wisconsin builder Marshall Erdman. After visiting two in Wisconsin, they ordered one for their 15-acre home site at 2255 Edgebrooke Drive in Lisle, a Chicago suburb.

Between 1956 and 1961, 11 Erdman prefabs were built in Wisconsin, Illinois, Minnesota and New York, from two of the three designs Wright created for him. The Duncans chose Prefab No. 1, with three bedrooms, two baths and a carport. The L-shaped house could be expanded in increments and gain a fourth bedroom and basement.

Accented with Wright's signature color, Cherokee red, the designs were distinctive but the materials common. Outside and in, the walls are wood products -- cream-painted, textured Masonite boards on the exterior and blond-stained mahogany plywood within, mounted on 2-by-4 stud framing. Inside and out, the horizontal panel seams are covered with triangular strips known as battens, lines that are echoed in the pattern of the roof shingles.

The saltbox-shaped roof, ending in deeply overhanging eaves, is most apparent in the living room, where the gable soars to 15 feet at its peak. All of the rooms have built-in cupboards or closets, another feature that ties the house to Wright's larger body of work.

For Prefab No. 1, Wright designed a masonry core that held the fireplace and could be concrete, brick or stone. The Duncan House's original concrete has given way to stone, stacked randomly but with protruding bands that pick up the lines of the battens.

"The Duncans wanted to meet their architect, and so they went out to Taliesin West," William Allin Storrer writes in his 1993 book, "The Frank Lloyd Wright Companion."

"They were advised to sit under the bell and enjoy the beauty, for 'Mr. Wright will eventually come by.' He didn't. Don got tired of waiting. On the way out, he had to pass through Mr. Wright's office. The architect was 'very gently' interviewing a Chinese student who had with him some drawings. When the student left, Mr. Wright approached Don and shook hands. 'Mr. Wright, we never expected to meet you.' Mr. Wright's nonagenerian reply: 'Young man, you're very lucky.' "

Wright was almost 90 when he designed the Erdman prefabs; he died in 1959.

Although the houses were meant to be affordable, the Duncans paid $47,000 for theirs, including construction. That's $344,000 in 2007 dollars, and that's what doomed the Erdman prefabs. They weren't so affordable after all.

The Duncan House had badly deteriorated, so this big-hearted relocation project was as much a restoration as a reconstruction. It's a stellar achievement that, with Fallingwater and Kentuck Knob, gives Western Pennsylvania a trio of worthy Wrights.