BCA worked with the National Park Service (NPS) to perform a conditions assessment of the masonry portions of the U.S. Capitol Gatehouses and Gatepost located in President's Park South, Washington, DC. The gatehouses and gateposts design is attributed to Charles Bulfinch, and they are often referred to as the Bulfinch Gatehouses. Constructed in 1814, the gatehouses and gatepost were originally located on the west capitol grounds until 1874, and were reconstructed at their current location in 1880. All of the structures are built of Aquia Creek sandstone. The gatehouses and gatepost were placed on the National Register of Historic Places in 1973.

BCA performed archival research into the original gatehouses and gateposts in the park, reviewed previous materials analyses performed on the structures, and conducted a comprehensive on-site survey of current conditions. Following that work, BCA performed cleaning and consolidation tests to evaluate suitable materials and methods to use on the sandstone. BCA prepared a report that documented existing conditions, summarized results of the on-site testing, and developed treatment recommendations. BCA used this information to create construction drawings and specifications for the restoration of the gatehouses and gateposts. The report and construction documents are being used by NPS to inform a plan for future conservation work on these structures.