Beside Prince George's Country's glassy new office building in Upper Marlboro stands the Waldrop-Buck house, a deserted and decaying symbol of the declining fortunes of many of the county's historic buildings.

Once dotted with magnificent plantation houses, inns and lovely 18th century churches -- in the days when Prince George's, not Montgomery, was Maryland's upper-class county -- today there are fewer than 550 historic buildings remaining in Prince George's, and the number is dwindling monthly.

To help preserve those historic buildings still standing, the Prince George's Planning Board has scheduled a public forum Jan. 10. The board will ask for assistance in preparing a historic sites and district plan for the county, something the planning agency proposed first in 1969 and again in 1974. c

Prince George's is one of the few jurisidictions in the Washington area without a detailed list of its historic sites, and without regulations to protect them.

Neighboring Montgomery County earlier this year passed strong protective legislation, to be enacted as soon as the county council appoints a commission to oversee the regulation.

The Waldrop-Buck house -- so called after the Waldrops and the Bucks, the first and last families known to have occupied it -- was bought by the county in the early 1970s as part of an 11-acre site planned for county office buildings. The county planned to demolish the building, which is on a small hill overlooking School House Pond, but then discovered it was older and more historic than previously thought.

Historians now believe the pre-1740 building may have been built by Maryland's prominent Carroll family. Both John Carroll, the first American-born Catholic bishop, and his brother Daniel, a signer of the Constitution who is credited with drafting the First Amendment, were born in Upper Marlboro in the 1730s.

The county has been unwilling to spend the money needed to restore the building, however, even though it received a $52,000 state restoration grant and a similar amount of federal historic preservation funds was made available. The county is willing to seel the house to anyone, even a bank or restaurant, who is willing to spend the estimated $400,000 to $600,000 cost of restoration, according to county officials.

"We'd sell it for a dollar to someone who would guarantee to restore it," County Executive Lawrence J. Hogan earlier this year told a group visiting his office, which overlooks the Waldrop-Buck house.

While the Waldrop-Buck house is safely within county ownership, although boarded-up and deteriorating, most of the other historic buildings are privately owned. A number of them are threatened by development plans, county officials say.

Two 19th century Prince George's buildings were demolished within the past month: "Greenland," an early farmhouse near Upper Marlboro, and the 1824 Chillum Castle Chapel near Bladensburg, which was the burial place of Washington's original planner, Pierre L'Enfant.

"We didn't even know the chapel was torn down until someone wrote us a letter complaining," said John Walton, coordinator of the Prince George's Planning Board's history division.

Susan Pearl, Walton's research assistant, is preparing an inventory of the 150 to 170 most important historic sites in the county. Pearl said. "I heard about (Greenland) just hours before they were to burn it and raced out to get some pictures of the building." The owners of both properties routinely had been granted county demolition permits. o

Under historic preservation laws in Alexandria, the District, Montgomery and many other jurisdictions, such buildings may not be demolished without the permission of local review boards. Whether Prince George's will enact similar protective legislation is unclear.

The county council has asked the Maryland National Capital Park and Planning Commission to draft a plan to help protect historic sites, but planners say the emphasis appears to be on incentives to keep historic buildings rather than on prohibiting their alteration or demolition. Carrots, but no sticks.

"We've had that kind of regulation for something like 30 years in Montgomery County and it didn't work. That's why the new legislation was passed," said Montgomery planner Mike Dwyer, who two years ago helped prepare a quick inventory of historic building in both counties.

That inventory found about 1,000 historic buildings in Montgomery and about 550 in Prince George's. Most os the Montgomery sites were modest farms, but those in Prince George's included many large mansions -- appropriate for the wealthy Tidewater plantation county that produced about 75 percent of Maryland's tobacco until the Civil War.

"Prince George's had many manor houses, tobacco barns and slaves . . . 50 percent of the population was slave," said Dwyer. "Montgomery, on the other hand, was composed mostly of middle-class yeoman farmers. There were almost no tobacco barns, but large Pennsylvania-Dutch bank barns, and less than 10 percent of the pre-Civil War population was slave."

The Planning Board public forum on historic preservation is to take place Jan. 10 at 7:30 p.m. in the parks and recreation building at 6600 Kenilworth Ave., Riverdale. Those wishing to comment in writing for the hearing record may do so until Jan. 17, by writing the planning board at 14741 Governor Oden Bowie Dr., Upper Marlboro, Md. 20870.