Out on architecture's furthest frontier is Michael Jantzen of Carlyle, Ill., who has designed an energy-efficient dome home made of silo covers. The house, built for his mother and four sisters, is situated just off a two-lane highway some 45 miles east of St. Louis. It looks like four huge scoops of ice cream that melted into one another under the warm Illinois sun.
The ''silo house'' is squat, yet rests lightly against the earth at dusk, appearing more at home with the sky. Perhaps for this reason, Mr. Jantzen says, some observers have likened it to a spaceship.
''I'm not trying to design a nutty-looking house,'' the architect insists. ''A lot of people try to do that. There's a much broader issue here. The house is purely functional and is designed for energy efficiency. It's not how much energy you have, but what you do with what you have.''
Despite his distaste for the ''Star Wars'' metaphors so often used to describe the house, it does look a lot like something from outer space, especially in the evening with the lights glowing eerily from porthole-type windows.
Although each of the windows is fitted with louvers to adjust the amount of sunlight warming the home, Jantzen emphasizes that the house is not a solar home. It is a ''superinsulated'' structure that is designed to retain the heat produced by incandescent light bulbs, appliances, and the people living inside.
So efficient it took only a cord of wood and a small wood stove to heat in last year's record-cold winter, Jantzen says the house is a prototype of a mass-produceable home that is flexible and affordable as well as efficient.
While his mother and sisters stay warm and dry in their domes, Jantzen and his wife, Ellen, live nearby in a solar home the couple built together a few years before his dome idea.
Entry to the dome home is through an arched doorway and into an airlock. Closing the outer door of the tunnel-like entryway, and opening the inner door, a visitor emerges into a surprisingly spacious interior, in which the walls curve in toward the center of the ceiling.
The wide-open feeling inside isn't just an illusion. The domes' aura of expanded inner space is enhanced by putting several of them together. The connection is made by cutting arches into the side of each and matching them together.
Visually, the two rooms merge at the archway.
But from the outside, an observer sees a house that is low to the ground and hardly big enough to live in.
''There's an illusion if you are looking at a dome from the outside,'' Jantzen asserts. ''Everything is curving away and it looks smaller than it actually is.''
Inside, however, there is comfortable economy in the furniture, which was made by the architect himself. Just about everything does double duty. The kitchen table, for instance, has a shelf underneath to hold dishes, while a couch in the bedroom converts to a table and bed.
In the kitchen the special halogen light bulbs use less wattage, but are brighter than incandescent bulbs. Too, heat from the refrigerator dries herbs on a rack above it.
Because ordinary rectangular furniture occupies space inefficiently in a house with curved walls, Jantzen built modular flat-topped pieces with faceted, angled sides that fit against the walls and have cabinet space beneath.
In his sisters' dome the desks fit against the wall and are adjustable to make an angled drafting table. In the center of the room is a quad bunk bed with two bunks to a side and a divider in the middle. Closets are also modular, with simple pull-up shades instead of doors.
The concept of using interconnected domes allows the owner to add or substract domes, porthole windows, and doorways as required, Jantzen says.
In theory, the dome home should appeal to anyone who wants to be in complete control of his living environment, says Jantzen, yet the architect concedes that the dome house isn't particularly suited for the city and ''isn't for everybody.''
Concern for saving energy grew both out of his rural background and his artistic ideas. During the 15 years that followed his graduation from Southern Illinois University at Edwardsville, Jantzen says, he experimented with art that could be lived in.
''I looked around for some time for a structural shell system already being manufactured,'' he adds. ''I finally decided to play around with my first silo roof in 1974,'' meaning the idea of putting one dome inside another.
Each dome in the house is actually a small dome within a larger one. A foot of cellulose insulation in between makes it a home that loses little heat in winter and gains little in summer.
Last summer, for example, the temperature in the dome house stayed in the 70 s. This year's record heat wave forced Jantzen to install a small air conditioner that easily cooled the 1,640-square-foot living area.
Using the obvious in a unique way has been a Jantzen trademark, one he says he developed because he didn't have the money to buy building materials. He has yet to make money from the silo-dome idea.
In 1979, Ted Bakewell, a self-styled St. Louis energy-conservation pioneer, read about Jantzen's silo experiments and the two became partners, soon gaining international recognition in architectural magazines, books, and other media for their autonomous dwelling unit (ADU), a kind of mobile home with parts of a silo dome and state-of-the-art technology.
That project uses photovoltaic cells to convert sunlight to electricity, collected and purified rainwater for drinking purposes, and burned trash in a small stove to provide heat.
The idea was to create a home that could provide instant housing, possibly for oil-drilling crews, anywhere in the world. Jantzen is now working on an advanced version of the ADU.