Mary Lee Cashell has lived in Silver Spring's Falkland Apartments since 1942 when she, her sister and mother moved to the 450-unit garden complex just north of the District line.

In 43 years, Cashell has moved three times within the complex. During the past five months, she and her sister left their apartment for three months while it was being refurbished by Crow, Terwillinger & Michaux Inc., the owners and developers of the project. The Cashells' apartment was among the first of about 120 units to be renovated under a plan calling for the developers to maintain the buildings as rental property until at least the year 2000.

Cashell and her sister Nellie, who are in their 70s, now pay $130 more a month in rent, but they said their "new" apartment is worth the inconvenience and three-month wait.

"It's a different world now," Mary Lee Cashell said. "The sidewalks are not broken anymore. We have a new kitchen and we feel much more secure walking around the complex." She said the roaches that once plagued the kitchen area have disappeared, and the whole moving process was handled smoothly.

But not everyone is as pleased as the Cashells with the renovation that is scheduled for completion in late 1987. Sharon Sherrill, president of the 250-member tenants association, said she still is concerned about what will happen to the Falkland Apartments after the year 2000. Under the county's 1970 master plan for Silver Spring, the property is zoned commercial and could support a mixed-use development "10 times the present density," she said.

The renovations followed a four-year fight by the Falkland Tenants Association to buy the complex and turn it into a cooperative or to have the area declared a historic site so it could not be razed.

In 1985, Crow, Terwillinger bought the Falkland site -- across from the Silver Spring Metro station and considered prime commercial real estate -- from Montgomery County's Blair family for just under $10 million. The company then negotiated $28 million in tax-exempt financing from the county's Housing Opportunities Commission to renovate the deteriorating 50-year-old buildings that straddle East-West Highway and 16th Street north of Colesville Road.

Under the terms of the loan, the developers must keep the complex as rental property until 2000. In addition, 20 percent of the units (90 apartments) are to be set aside as rentals for people whose income falls between 20 and 50 percent of the Washington area's median income of $41,700, said project manager Rick Saunders.

The developers also agreed to pay moving costs for renters who moved out of the complex to location within a 30-mile radius or who moved to a vacant Falkland apartment while their unit was being renovated. Those moving out of the metropolitan area get $720 for moving expenses.

Mary Lee Cashell said the past two decades at the Falklands have been "years of turmoil" during which she and her sister "and other old-timers" waited to see what developers would do to one of Montgomery's oldest garden apartments and the first Federal Housing Administration-insured garden complex in Maryland.

Now, Sherrill said she worries about tenants who make too much to qualify for one of the 90 subsidized units but not enough to afford the higher rents that come with the new heating and cooling systems, laundry facilities, buffed hardwood floors, modern kitchen appliances and upgraded baths.

At the moment, Sherrill pays $700 for a three-bedroom town house. But after it is renovated this year, the rent will be about $900, not including electricity, she said.

"I look at the rehab in a different light than others may. I see it as something the tenants could've done less expensively had we acquired the property ourselves," she said.

She questioned the county subsidizing a renovation project that might force people to move unless they are willing, or able, to spend much more of their income on rent.

Saunders said the developers have been complying voluntarily with the county's limit of 5.6 percent for annual rent increases on apartments not yet refurbished. But he said he was not sure rents on remodeled units could be kept under that limit. He said the county's guideline is somewhat "unrealistic because it lumps older complexes like this, with high upkeep costs, together with new projects that are less expensive to maintain. . . . We hope to be able to keep increases to 5.6 percent, but we have no commitment."

Sherrill said, "If the buildings are demolished 15 years from now, the rehab will be wasted. The county won't get much return on its investment. And if the buildings are converted to condos after the year 2000, we don't think the county should subsidize a rehabilitation for a conversion."

About 60 percent of the tenants in the 62 newly renovated apartments have stayed, Saunders said. And about half of those in the 58 units under construction will return to their apartments, at higher rents. The complex is the only garden apartment within half a block of the subway, enhancing its popularity with long-time and new residents alike. Its location is unique because of its 22 acres of wooded grounds, including a meandering creek and because of its easy access to Silver Spring's central shopping area, said Mary Lee Cashell, who would rather ride to downtown Washington on the bus than on the subway.

A person who never has rented at the Falkland Apartments can get a one-bedroom unit for between $525 and $555, depending on its style. A renovated two-bedroom unit would rent for about $650 to a first-timer, Saunders said.

The area surrounding the Falkland has changed dramatically since 1943, when Cashell and her sister first became tenants and 16th Street, extending from the District, dead-ended at their apartment door. But Mary Lee Cashell says, "It just takes a little getting used to. We still love it, and we're not going to move again."