New Mattapan Health Center Topping-OffMattapan Community Health Center celebrated a milestone in the construction of its new facility with a topping-off ceremony this afternoon. Patients, staff, neighbors and supporters signed a steel beam that was placed on the top of the new four-story building that is rising at 1575 Blue Hill Ave. The $34 million building - due to be complete next summer— will also house a pharmacy and bank branch.