It's not uncommon around here for people preparing to build a single-family house to hire an architect to custom design their home. But it is uncommon for prospective residents of a multi-family project to get that kind of custom treatment.

Recently, however, one local architectural firm has undertaken the uncommon, putting together an advisory panel of local residents to help them design Thoreau Place, a Reston condominium project for persons 55 and older.

With that unusual approach, the architects believe they have come up with a building concept that is unique in the Washington area and possibly the first of its kind in the entire nation.

"A lot of architects seem to look down their noses at other people," commented Sally Hechtman, one of the nine Reston residents who served on the advisory panel. "I was impressed with the humility of this group of architects. Part of the reason I got involved in this was their willingness to learn from us."

Speaking of the meetings his firm's architects had with the advisory panel members, Environmental Design Group architect Don Tucker explained, "We'd say, 'Here's what we think. What do you think?' We'd start with an agenda, to address specific issues. Mainly it was a seminar-type discussion.

" The advisory panel had lots to offer. Lots of the features we incorporated were their ideas."

One of the most innovative characteristics of Thoreau Place will be its ability to accommodate the changing needs of the residents as they grow older. Two common housing choices for many elderly persons are life care communities and nursing homes, commented Tucker.

"Many of those projects don't acknowledge the aging process," Tucker said. "Older people as a group do have a definable pattern of needs. Most buildings lock into that pattern and can't change. A person who is fully independent at 62 may need special assistance at 82 to continue living independently."

Part of the project's ability to accommodate the residents' future needs comes with the initial flexibility EDG has designed into the building. For example, all of the doorways will be wide enough for wheelchairs. One row of kitchen cabinets will be easily removable to provide enough space to maneuver a wheelchair.

Besides the kitchens in each of the apartments, the building will also have a much larger common kitchen. Initially, that will be used for an optional light food and beverage service for the residents. In future years, that same facility can be used for full meals if the condominium association members decide they want that.

Another major emphasis of Thoreau Place--named for Reston's nearby Lake Thoreau--will be to keep the older residents healthy and active for as long as possible. The 140-unit building will incorporate a "wellness clinic," which will offer programs in exercise, nutrition and flexibility.

"With our aging population, you have to look at a holistic approach to aging," commented Audrey M. Raphael, who will run the center. "As a nation, we haven't been doing that. We've been doing it bit by bit."

The wife of one of the Environmental Group architects, Raphael is a gerontological psychologist who advised EDG on a number of design aspects of the project.

"The whole emphasis is to keep people well as long as possible, but as they need services, provide them," explained Tucker. "With most life care communities, you're paying for the nursing wing as soon as you move in."

Some such facilities in this area charge as much as $40,000 as an initial entry free, plus $700 or more per month in rent, Tucker said.

"With proper attention," he said, "only 4 to 5 percent of elderly people ever require permanent, skilled nursing care, but our society is oriented that way. The emphasis of this project is to keep people out of a nursing home."

When they are ill, many elderly persons stay in a hospital or nursing home longer than necessary because they have no one who can help attend to them. The condo project will have a special "convalescent center" staffed by a nurse. Instead of prolonging an expensive hospital stay, Thoreau Place residents will be able to return to the building and finish recuperating in more familiar surroundings.

When not needed for sick persons, the convalescent center rooms can be rented out to guests of Thoreau Place residents.

Many of the initial ideas for Thoreau Place grew out of Environmental Design Group's work with other elderly housing projects, including several low- and moderate-income government-assisted ones. An EDG architect, Agustin Costa, approached one of his Reston neighbors, Fran Grady, and asked for her help in setting up an advisory panel. "I have strong feelings about architecture and design," Grady said. "I don't feel enough attention was being paid to the needs of one- and two-person households in particular."

Over the past year, the EDG architects have met a number of times with the advisory panel. One day the architects and the panel members went together to tour several elderly housing projects. Speaking of the panel's role, Tucker commented, "They've been in on the policy decisions, everything from where to place the laundry facilities to whether the project should be ownership or rental."

One of the most important decisions the panel strongly urged on the architects was the overall layout of the building. It will be diamond shaped and open in the center, to provide space for a large courtyard, fountain, and social facilities.

The planning is still going on for the project during the current pre-sale period, which began just a week ago. "We've done market research and we're doing a mail survey now," Tucker said. "But the best test is the sales program, so we can make final adjustments." Depending on market demand, some of the planned one-bedroom units may be combined to make more two-bedroom apartments.

One-bedroom units are priced from $68,000 up to $74,000. Two-bedroom apartments will go for between $110,000 and $120,000. Interested buyers can sign non-binding reservations now and later convert them to formal contracts. Two of the advisory panel members have already reserved apartments, Tucker said.

The enthusiasm for the project extends beyond just the architects and the panel members. "I'm an ex-federal government employe and I'll be 55 about the time the project is ready for occupancy," commented Bill Gavaghen, a real estate agent who will be handling the project's sales for the Long & Foster agency. "I'm seriously considering buying a unit myself."

Once about half the units are pre-sold, construction will begin, probably this winter or next spring, according to Tucker. The project should be ready for occupancy in the spring of 1985.

One characteristic that may attract a number of buyers is the possibility of joint ownership of units by their elderly occupants and other family members. Under that arrangement, a relative could have partial ownership of the apartment and could charge rent for it. The portion of the apartment's value held by the relative could also be depreciated. "The net, after tax cost to the family," Tucker said, "is practically nothing, especially if you take into consideration the appreciation on the unit."

While the financial aspects of Thoreau Place may attract many buyers, Tucker and all the other persons involved in the project's design are confident the consideration given to the aging residents' future needs is just as important. "I found nobody was designing for the future," commented Audrey Raphael. "My concern is to see that people are designed for, not just that buildings are designed."