The Custom House Block is a five-story building on Boston's Long Wharf that is clad primarily in brick, with the exception of its main, south elevation, which is clad in granite block. Built in 1848 in the Greek Revival style, the warehouse building postdates its supporting wharf by over a century. In 1966, the Long Wharf and Custom House Block were designated as a National Historic Landmark. The building is undergoing both interior modifications and exterior restoration to accommodate its reuse as commercial office space.

BCA completed extensive historic research of the building as part of preparing the National Park Service Historic Tax Credit application, which partially funded the restoration of the building. BCA also surveyed the exterior conditions of the building, prepared restoration drawings and detailed specifications for masonry restoration Construction Documents, materials testing, and Construction Administration. To date, the north and east exterior elevations have been completely restored.