Baltimore County officials broke ground on Wednesday on a $4.18 million expansion and renovation of the Pikesville Senior Center and Library, kicking off one of the most extensive facelifts of a county-owned service building in history.

The project ? which will add 3,500 square feet to each facility plus a 1,500-square-foot fitness center ? is the first since the community center that houses both was built in 1982, officials said.