The Zoning Board of Appeal on Tuesday approved plans by Rainbow Adult Day Health Care Center to open a new facility at 60-64 Hill Top St. in Dorchester.

Rainbow, which already operates several of its facilities in the Boston area, including one on Freeport Street, will use the 10,000-square-foot first floor of that building for social, recreational and nursing services for roughly 100 senior residents a day, its attorney, George Morancy, told the board.

The space will include a large activity and dining area as well as smaller rooms for quieter activities and nurse's offices for participants, who have an average age of 75, Morancy said.

The center will be open 8 a.m. to 3 p.m., Monday through Saturday, he said, adding the roughly 20 employees will have office hours until 5 p.m.