Small is smart; energy-efficieny is expedient. The 1980s will be shaped by those words. So say the architects planning the homes of the future.

"We can't produce ticky-tacky boxes," said J. Donald Bowman, of Mithun Associates in Bellevue, Wash. "We have to build small -- but small with exciting design.

"We have to look to the auto industry. Its success has been in the development of small cars. But those small cars are offered with terrific options," he said. "People want to economize, but they want to stick with the luxuries that they have come to expect as necessities."

For most, there is a difference between what they want and what they can afford. Something has to bridge the gap between affordability and appeal in the home market.

Architects and designers, who were in Las Vegas earlier this year to share ideas at the National Association of Home Builders convention, made it clear they believe the '80s will see an end to big, rambling homes. Small will be smart -- not only because it conserves materials and lowers land costs per unit, but because it saves energy, as well.

"We are opening the door to a new housing type," said Jack Bloodgood, a Des Moines, Iowa, architect. "In the '60s, bigger was better. In the '70s, the wife went to work so we could afford bigger and better. In the '80s, we don't have anyone else to send to work, so we had better look at the alternatives.

"We need town homes and apartments with the feeling of home to suit the characteristics of the new buyers -- the singles, the divorced, the single heads of household, the unrelated singles sharing a purchase. We need to get the maximum impact of space inside and out," Bloodgood said.

"If we don't adapt to the new-age design criteria, including energy concerns, we may well go the way of the dodo," said R. Randall Vosbeck, president of the American Institute of Architects. "How people use energy is determined at the design stage. It goes beyond insulation; it goes beyond thermal mass, groupings and materials. The design goes back to the pueblo clusters, to the hillsides of Greece, to the tight clustering of European homes."

The quality of space will be where emphasis lies in the '80s, say the experts.

Here's what experts predict the next 10 years or so will bring:

Clustered housing. Homes will share walls with neighbors in order to take advantage of solar orientations and share the high cost of items like driveways and street entrances. The clusters will be enhanced with waterways and landscaped greenspace to tie units together and give a neighborhood character.

Duplexes and zero lot line homes. Houses built along one lot line offer a maximum of usable yard on smaller lots. Duplexes team zero lot line configurations with multiplex conservation of energy and materials using only one shared wall. Both designs offer maximum privacy at a higher density.

"The duplex is marvelous for energy conservation. Two single-family homes are put together for mass but provide three sides for light. A duplex can provide a strong open land arrangement while providing open space and solar orientation," said Barry Berkus, Berkus Group, Santa Barbara.

Function. The emphasis on square footage will be transferred to how an area can function. A small bedroom, for instance, with proper furnishings can offer sleep, play and storage space. More builders will use model homes displays to instruct buyers in functional options within smaller rooms. Multiple-use rooms such as the great room (combination of living, dinning and family room) will dominate new home design.

Cubic space. Small areas must live big by utilizing all space. Furniture that hangs on the wall, tucks out of sight or serves more than one function will play a big role in the home of the future. Volume ceilings, mirror treatments and lighting will provide visual spaciousness.

Baths and kitchens. Both the kitchen and bath are deemed important design areas in the smaller home. They are seen as areas of social activity as resort overtones large amenity packages focused toward relaxation and energy savings.

Outside. Exteriors will return to traditional forms with a contemporary touch. Regionalism, such as the Southern colonial and New England saltbox, will again exert in influence on exterior design. The home will extend to include the whole lot, which will be made usable with decks, pools and spas. The outside area will become more useful for family living and entertaining. Placement of the home on the lot will allow for the use of natural ventilation and direct sunlight as energy conservation designs and there will be more earth bermed and earth sheltered homes on the marketplace.

"The best thing to come of all this," said Rodney Friedman of Fisher-Friedman in San Francisco, "is that designers and land planners are going to have more fun with these complex projects."