The Most Beautiful House in the World [Paperback]

The book owes its arresting title to Joseph Rykwert, chairman of the doctoral program in architecture at the University of Pennsylvania, who invited Mr. Rybczynski to address his seminar on the subject of a design competition sponsored by an Italian journal. The author responded, ''The most beautiful house in the world is the one that you build for yourself.'' In a previous study, ''Home: A Short History of an Idea,'' Mr. Rybczynski, who teaches architecture at McGill University in Montreal, went beyond architecture to provide a fascinating historical exploration of domestic well-being. In his new book, he tells what it means to build his own home.

First Mr. Rybczynski dreamed of a boat, then of a shelter to build it in - something between a shed and a cathedral. He and his wife, Shirley Hallam, decided to include temporary living quarters in the plan, with the idea of constructing a house nearby sometime in the future. They chose a site, he ruminated over designs, enlisted the help of his wife and his friend Vikram Bhatt, an Indian architect. They poured a foundation before completing the design. In vacation periods, on weekends and afternoons after work they put their energies into the project. Mr. Rybczynski assembled notes, made drawings, jotted down reflections on architecture and reviewed the experience of his practice. This building, in the reader's mind, grows larger than a shed or even a cathedral; it concretizes architecture and all its connections.

As time passed the author wondered: a boatbuilding workshop or a house? The living quarters expanded and the intended boat shrank from dory ketch to catboat. The building should look traditional; it must fit the location, speak the local language. He chose the form of a barn. Vast barns dominated the landscape, he explains, ''and if my building was to fit it, it could only be as a little offspring of these heroic leviathans.''

For a year and a half he immersed himself in its paper existence, gestating a hybrid dream that looked like a barn but sheltered boatbuilding at the west end, living quarters at the east. Then these three builders, colonists in the meadow, people with little experience in construction, put up frame and sheathing in a few weeks, working with hand tools. They changed the place, occupied the meadow; it was ''the reenactment of a primeval process that began with the first hut erected in a forest clearing, and it gave me the feeling of playing out an ancient ritual.'' At sunset the glass bottles of the final wall ''blazed with the amber and emerald colors of several hundred wine and liquor bottles - a bacchanalian rose window.''

The physical house sank the maritime dream, partly in the weariness of construction, partly by fulfillment. He explains: ''After years of designing on the drawing table . . . I had wanted to build something, anything, with my own hands and with proper tools and real materials.'' The Rybczynskis turned the boatbuilding workshop into living quarters, decided to make a comfortable permanent home instead of temporary shelter. This transformation changed Shirley from an associate builder into a client, who challenged him with questions, objections, demands. She had a better knowledge of house design than he, ''not of construction but of the details, of the minutiae of everyday life that constitute a home.'' She refused improvised solutions and rejected an inconvenient kitchen, insisting on a design that would not hide things in cupboards; she suggested important modifications in other rooms as well. Furthermore, the house did not look right; she wanted to dwell in a home, not a building that looked like a barn. It lacked the familiar signs of human habitation: proper windows, a porch, a chimney, a real front door. After the final changes, including a front door and portico, the house spoke a new message. ''It was a comforting sight as one came down the long drive. 'Welcome home,' it said.'' Five years after Mr. Rybczynski made his first sketch of a boatbuilding shed, he and his wife moved in.

The book acknowledges the wisdom of the French philosopher Gaston Bachelard, that a house shelters daydreaming. At home it is safe to let the mind drift, to let imagination wander. And dreams contain houses. Even though the author still calls his home ''The Boathouse,'' he concludes: ''My house had begun with the dream of a boat. The dream had run aground - I was now rooted in place.''

Most readers of this book are spared the labor and frustration as well as the fulfillment eloquently described here. Until recently it was not unusual for people to build their own homes - a privilege still reserved to the so-called underdeveloped world. For us, the experience is fragmented, divided among designers, contractors, tradesmen, brokers, dwellers. We may not be able or willing to dwell in houses we design and build, but this book makes it possible to recover in our imaginations that lost unity of experience.