An Anne Arundel County judge has set a Feb. 27 hearing for a preliminary injunction on whether officials must follow Annapolis rules to build an addition to a state-operated African-American history museum in the city's tony historic district.

No excavation can take place in the meantime, under a restraining order worked out behind closed doors yesterday by the state, the county, the city and property owners who filed the lawsuit this week.

"This is a win," said lawyer Thomas C. McCarthy Sr., whose son and daughter-in-law own a house turned into a law office that faces the Banneker-Douglass Museum.

State and local officials said the McCarthys won barely anything, as the agreement does not stop the Department of General Services from doing work planned for this month, mostly preliminaries such as erecting a construction fence.

Jessica and Thomas C. McCarthy Jr., who filed the lawsuit Tuesday, contend that the addition to the Banneker-Douglass Museum should not be exempt from city regulations and permits, arguing that it is an architectural misfit that would have benefited from oversight by the city's Historic Preservation Commission.