THE ROOF IS NOT ON FIRE.(hydronics uses water as construction material)

In the spring of 1947, William Katavolos is the solitary occupant of the Ram's Head Inn, on Ram Island, off eastern Long Island. Katavolos is twenty-three. His father has leased the inn. Katavolos has returned from the war and wants a place where he can paint and be left alone. The hotel is reached by a causeway from Shelter Island, and the causeway sometimes floods, leaving Katavolos as isolated as a lighthouse keeper. To amuse himself one evening, he puts some water in a glass, covers the rim of the glass with waxed paper, then presses the paper into the water to create a vacuum. He secures the paper to the glass with a rubber band, then turns the glass upside down. The water fills the vacuum, preserving the dome--it looks like the bottom of a wine bottle. Then he begins to wonder what would happen if he repeated the experiment on a larger scale. A few days later, he throws a tarpaulin over a section of Gardiners Bay. He weights down the edges so that no air can get beneath the tarpaulin, then he swims underneath it. Using two oars, he raises the center of the tarpaulin. The water fills the cavity, and he swims into it, floating above sea level, which, he says later, "fascinated the hell out of me." This is the beginning of what Katavolos will call hydronics, the practice of making buildings from soft plastic forms filled with water.

In 1949, Katavolos gives up painting to design furniture--his chairs are in the collections of the Museum of Modern Art, the Metropolitan Museum, and the Louvre--and in 1960 he begins teaching architecture at the Pratt Institute, in Brooklyn, where he will become the co-director of the Center for Experimental Structures. In 1970, in a courtyard at Pratt, he builds the first hydronic structure--a plastic dome filled with water and supported by a plastic cylinder, also filled with water. The plastic is like Saran Wrap, only thicker. Each year after that, he builds a new structure. He calls the structures liquid villas. They consist of columns, arches, and vaults--the elements, that is, of classical architecture. Katavolos sometimes describes hydronics as "the attempt to arrive again at classical forms, for new reasons."

Katavolos regards water as an immensely sensible construction material. To begin with, it's cheap. It's also safe; buildings made from water don't usually burn. If a hole is made in ...