Suburban renovation

Like many couples, the Hamilton Harts live in a typical small suburban colonial home that was built in the 1950s. They raised their family in this brick and shingle three-bedroom house. But now that their children are grown, they occupy the house alone.

Last year they considered their alternatives, which included selling their home and relocating to an apartment in New York City. They finally decided to stay put and remain suburban dwellers, but to have the first floor of their home completely redesigned and refurnished to meet their current needs.

The couple's situation is commonplace. In a national survey of 2,000 professionals conducted this spring by the American Society of Interior Designers, 24 percent of respondents replied that a significant amount of their time now went into the ''redesign of homes for empty-nesters.''

The Harts asked New York interior designer Michael Braverman to help them attain the new look they wanted. They specifically told him they wanted low and easy maintenance, additional sleeping area for grandchildren (without the use of a sleep sofa), and increased space in the dining area for books, stereo equipment, and general storage.

Since their existing layout only allowed for uncomfortable dining for six, they asked if it could be expanded to enable them to have a traditional sit-down dinner for eight, as well as serving space for buffet entertaining.

They wanted to revitalize areas not sufficiently utilized, and they referred to their present formal living and dining rooms as mainly ''walk through'' areas. Finally, although they had chosen not to move back to the city, they told the designer they felt ready, after 35 years of marriage, for a ''unified and tranquil, yet exciting, contemporary urban-type environment.''

They had been living with traditional furniture of ''early marriage'' vintage , heavy draperies over the windows, overstuffed seating, a few antiques, and a few oil paintings.

After analyzing their home, Mr. Braverman developed an open plan (for the former three small boxlike rooms) that reallocated the space to fulfill their stated requirements.

He converted the original living room into the new dining area, the former dining room and part of the old living room into a big new living-den. He skipped the designation ''living room'' altogether, although there is a new lounge-sitting area. A soffit-covered ceiling beam defines the areas and adds architectural interest.

Further interest was developed with the ''stepped'' fireplace wall, which contains storage cabinetry as well as surfaces for buffet entertaining and the display of art.

A platform was built along one den wall as a base for an upholstered mattress and pillows. This serves for extra seating as well as sleeping space for a visiting grandchild.

The newly developed den also contains built-in storage to house books, photos , stereo, and TV. A 28-inch-high table functions as a work, eating, and reading surface, as well as a coffee table.

Two dining tables were especially designed with casters, so they could be quickly rearranged together for large sit-down dinners and used separately for intimate dining. These tables of polished aluminum and polished marble also allow various buffet arrangements and can serve as card and game tables. The neo-Gothic mahogany console that shares the dining area is one of the few pieces retained from prior furnishings.

Mr. Braverman chose two Mies van der Rohe lounge chairs for their classic sculptural lines, as well as for their mobility and comfort. A coffee table was inexpensively constructed as a carpeted platform with a black glass top. He unified all the areas with a tightly woven industrial carpet, chosen for its clean-cut look and its durability. The designer also helped his clients develop a contemporary art collection, which includes weavings, ceramics, a glass and copper sculpture, and a piece of art constructed of handmade paper.

This partial transformation of an over-30 house cost $42,000, which included all new construction, new furnishings, and painting the exterior a handsome putty color, but not artwork and accessories.

Mr. Hart works out of a second-floor office at home, and his wife goes to a job outside the home. Both claim their spruced-up interior has given them a new reason to enjoy home. ''We sometimes feel like we moved and are beginning all over,'' Mrs. Hart says.