43, Milsom Street

43 Milsom Street is a former house, now serving as the offices of the Royal Photographic Society. Built around 1765, it underwent alterations in 1980. The building is constructed of limestone ashlar and features a double-pitched slate mansard roof with dormers and moulded stacks on the right side.

The exterior consists of three storeys with attics and a three-window range. It has a stepped coped parapet and a stopped modillion cornice. The second-floor windows are adorned with eared architraves, while the first-floor windows have lowered sills and moulded architraves, with cornices on the outer windows and a pediment above the center window. The plate glass sash windows have painted splayed reveals on the first floor, where "Circulating Library and Reading Room" is painted on the wall above. Fluted Ionic pilasters flank a 20th-century door, with a blocked overlight to the left and far right, and a moulded cornice and fascia above the 1980 shopfront on the right. Additionally, there is a well-crafted fluted lead rainwater head connected to a lead downpipe.

The interior has not been inspected, but it serves as the entrance to the Royal Photographic Society gallery located in the old Octagon Chapel. The house features a standard elevation, likely designed by Thomas Jelly, and the 1980 shopfront, created by Roy Worskett of the local planning authority, may incorporate elements from an early 19th-century shopfront, particularly the pilasters. The painted advertisement is a relatively rare survival and adds to the building's interest.