To some Arlington residents, a plan to build a 297-unit retirement home in a county with an increasing elderly population and few retirement or nursing homes sounded like a good idea.

But nearly everyone who lives near the 20-acre site known as the Hendry Estate, where developers hope to build the $40 million Fort Smith Crescent home, is opposed.

They argue that the eight-story facility on a wooded slope above the Potomac River in the Potomac Palisades area would be located in the heart of a quiet, single-family residential neighborhood.

"It's a nice idea, but it's not for this neighborhood. It's not for anybody's neighborhood," said Donald Lucas, president of the Parkway Citizens Association, which four times has voted unanimously to protest the project, which would fall within the association's boundaries. The group has 90 paid members.

"There is no justifiable reason for changing the character of that property," Lucas added. "This is a residential neighborhood. This isn't a hot dog stand or a hamburger joint."

The civic group is not alone in its opposition to the plan submitted by a McLean-based developer, John G. Georgelas & Sons Inc. The county's planning commission and the National Capital Planning Commission, the planning agency for the area's federal properties, have voted unanimously against the proposal.

The Arlington County Board is expected to make its decision at a hearing on May 17, when the developers will seek a change in zoning and a special use permit for the home. The county commission's staff has recommended that the board reject the requests.

"We're always deeply interested in expanding the options for elderly housing," said County Board member Albert C. Eisenberg, who added that he does not favor the plan. "It's a very difficult type of project to build in that neighborhood."

"I see this as a real dilemma," said Board Chairman Mary Margaret Whipple. "It's a proposal that's really needed in Arlington. We really need retirement homes . . . . The question is whether this is an appropriate location."

Between 1970 and 1980, when the county's population dropped 12 percent, the number of residents 65 and older increased 30 percent, making it the county's second fastest growing age group. There are three nursing homes and three retirement homes in Arlington, almost all with long waiting lists.

George Boniface, a partner in the project, said the development would cover only about 15 percent of the land at 2411 N. 24th St. An existing house would be retained as guest quarters and another house would be built on the tract for Anne Pearce Hendry, widow of Dr. Ernest S. Hendry, who planted many of 36 species of trees on the site. The Civil War-era Fort Smith, also on the site, would be preserved.

From North 24th Street, the project would appear to be four stories tall. But from the George Washington Memorial Parkway all eight stories would be visible -- a feature that earned the National Capital Planning Commission's disapproval.

"The structure's intrusion into the continuous tree line on the Potomac River bluffs would result in an unwarranted adverse impact on the scenic values of this area," said a commission statement.

This point also was made by the county's planning staff, which added that the proposal is "clearly out of scale" with the surrounding neighborhood and could increase traffic by as much as 300 percent on North 24th Street.

Although the developer proposes to offer shuttle bus service between the site and the Clarendon Metro stop, Whipple said she does not think this would adequately ease traffic on the residential street.

The elderly population, she said, increasingly is composed of "very independent people who drive their own cars and are involved in a lot of activities . . . . I don't see how that street can handle the traffic from a building of that size."

If the board refuses to grant the changes, the developer still could build up to 43 homes under the current residential zoning for the land.

Lucas, the civic association's president, said that the neighborhood would prefer to have the area developed as a subdivision of single-family homes.

"We would rather not do that because it would desecrate too many trees," Boniface explained.

Lucas said residents fear that approval of the retirement home may lead owners of nearby land to seek rezoning for their properties.

He said residents also are anxious to avoid a possible repeat of an incident a few years ago, when the County Board granted a rezoning and extra density for a much-wanted retirement home near the courthouse. The firm involved went bankrupt and the land, with its lucrative new zoning, was sold to an apartment developer.

Boniface said that he does not expect his firm to face such a problem because of the financing formula developed for the project. Residents of the retirement home would make refundable payments of between $110,000 to $225,000, depending upon the size of their units. The money would be deposited in an interest-earning account.

This "endowment fee" must remain in the account until someone else moves into the apartment, "to protect everyone who's there," Boniface said.

In addition, the elderly residents would pay from $1,000 to $1,500 in monthly fees for such items as a support staff of about 50 persons, weekly maid service, utilities, transportation and a daily meal cooked on the premises.

The retirement residence also would include a small infirmary, with nurses on duty 24 hours a day.