A "lifecare" community is under construction in Carroll County, Md. The Baltimore-based Episcopal Ministries to the Aging Inc of Maryland, which pioneered with the high-rise Goodwin House in Alexandria, now is building low-rise cottages and apartments in a rural area. In this case, the life-care concept is such that an elderly person pays $19,000 to $57,500 for a house that will not be owned (but for right of life-time occupancy) and also pays an individual monthly fee of $525 to $610. However, the services include health care and three meals a day. The non-sectarian, non-profit community is being built on a 300-acre site donated by the Beasman family just west of Rte. 32 and north of Sykesville. Interested persons may write to Fairhaven, 105 W. Monument St., Baltimore 21201.

Saul Ritzenberg has confirmed that he plans to sell the 65-unit Chesterfield apartments at $315 Wisconsin Ave. NW for approximately $2.6 million to John Mason and Stuart Bernstein, who plan to convert the 19-year-old, eight-story building to co-operative ownership.

There's no real shortage of rental apartments in this area, according to leasing specialists who point to the increasing numbers of apartments listed in the classified advertising pages. In fact, John O'Neill, executive of the Apartment and Office Building Association, pointed out that there's almost a glut of available larger apartments in the city and suburbs. One of the reasons has be that many persons have been buying single houses, town house and condo apartments in record numbers in the past two years. O'Neill added that one large suburban rental complex with a strong occupancy (but a 40 percent annual turnover of tenants) has learned through exit interviews that 65 percent of the tenants leave to purchase their own dwellings.

Burr, Morris & Pardoe has announced that the Charles E. Smith Companies will sell the Walton House apartment at 3900 Tunlaw Rd. NW to attorney Meyer (Mike) Feldman and Gary and Scott Nordheimer for a reported $3 million. The new owners plan to convert the 100-unit building to co-operative ownership, offering tenants their units at $65 a square foot as opposed to $70 a square foot for new move-ins.

Rural or country real estate, which tends to move slower than offerings in urban area, has a panache all its own. For instance, a recent flier from machat Realty Inc., out of Boonesboro, Md., lists a 72-acre horse, beef or sheep farm as an "inflation beater." It has an old frame dwelling but "panoramic" views. Price: $125,000. Another offering includes 40 acres on a large creek. Broker Sydney Machat says it could be a horse farm, a gentleman's beef farm or a retirement dream spread. Asking price is $2,000 an acre but the out-of-town owner says "sell." . . . Don't all of them?

Sale of a 3-acre site in the Metro East triangle to Peoples Security Bank has been announced by James W. Rogers Associates.

SHORTLY: The Fairfax County Board is reported still studying the full meaning of a quote from builder Herbert Aman, who testified recently against increased fees. He contended that some developers do not even attempt to produced a finished design for their projects because "the county will redo it anyway." . . . Builder-developer Harold H. Sampson, whose Pinewood Development Corp., has built nearly 3,000 houses in this area, recently held a "do" to mark the completion of 10,000 houses built by Pinewood and predecessor Sampson brothers' firms (in Pittsburgh) since 1946. He said the first house delivered in Pittsburgh for $7,800 in 1946 was recently resold for $42,000. . . . Builder Gilbert Schultz, whose specialty runs to large, expensive houses, now is doing one with a wood foundation and a heat pump operated with well water. It's at 2120 Johns Hopkins Rd., Gambrills, Md., near Crofton. . . . His many friends in the home building industry will be among those who miss the upbeat personality of Daniel L. Robertson, who retired yesterday after 42 years with Washington Gas.