The Prince George's County Council voted yesterday to require that relics of the county's history, such as tobacco barns and slave cabins, be protected from the wave of residential development sweeping the area.

The legislation, commonplace elsewhere but the first of its kind in Prince George's, was pushed by preservationists worried that the housing boom might erase keys to the county's cultural heritage.

"Preservation is finally on the table," said David A. Turner, chairman of the county's Historic Preservation Commission.

The measure, approved 8 to 1, was part of a package of four bills passed yesterday. It puts teeth in an old law that encouraged the county Planning Board to preserve historic resources by amending the phrase "shall encourage" to "shall require."

Council member Camille Exum (D-Seat Pleasant) cast the lone vote against the bill.

Representatives of the building industry said the legislation will probably impede the growing housing market.

"It's going to raise the cost of housing, and the county will have less workforce housing available," said Leo Bruso, who runs a real estate brokerage firm in Upper Marlboro. "Something like this just further exacerbates the problem this county is already facing."

County Executive Jack B. Johnson (D), who supports the preservation effort, is expected to sign the measures within the next few weeks.

Anna Holmes, a preservationist who was able to mark the Bowie graves of her great-great-grandparents three years ago, said the bill will spare others from the devastation she experienced when she learned that her great-great-grandparents' home was no longer standing.

"I saw it, but I never got inside," said Holmes, who treasures a stone from the chimney of the century-old house near a Bowie plantation. "I tried all I knew how to get that preserved, but all my pleas fell on deaf ears."

Two other bills in the package clarify the Planning Board's authority to identify properties with archaeological significance. The final measure changes the qualifications for those who sit on the Historic Preservation Commission, including adding a representative from the county Board of Realtors. Commission members are nominated by the county executive and approved by the County Council.

One of the measures originally would have allowed the commission to determine whether preservation of a historic property was warranted. The council backed away from the provision after questions were raised about whether the council was stripping itself of some of its authority.

Ralph Grutzmacher, the council's attorney, told council members that the commission makes recommendations regarding the historical significance of structures to the Planning Board and the District Council, which makes the final decision.

Council Vice Chairman Thomas Dernoga (D-Laurel), the sponsor of the bill, said he plans to revisit the issue of the commission's authority during the next legislative session, which begins in January.

Council Chairman Samuel H. Dean (D-Mitchellville) said he hopes the commission and the Planning Board will look beyond slave cabins and plantations.

"We have houses that African Americans have lived in for five generations, houses that date back to the 1800s," he said. "There's a lot of rich history in this county, and it goes beyond slave cabins."

Council Chairman Samuel H. Dean said he hopes historic homes will gain protection.