Building 106, Chemical Defence Establishment, Porton Down

Building 106 at the Chemical Defence Establishment in Porton Down is a headquarters building constructed in 1916 for the Royal Engineers Experimental Station (Gas Corps), now serving as administration offices. The building is made of rendered brick and has an asbestos slate roof. It is a single-storey structure designed in a Colonial style, featuring a symmetrical layout with a central entrance and wings that end in cross wings, creating an extended H-plan.

The central entrance includes a pair of panelled doors topped by a floating segmental pediment supported by consoles. On either side of the entrance are two bays of timber paned cross windows, which are framed by rusticated raised quoins, all topped with a simple triangular pediment. Each wing consists of nine bays, also symmetrical, with the central bay slightly projecting and featuring a pediment and a window set within a wide architrave and apron. The wings at either end have five by three bays, with rusticated quoins at the corners and a central bay on each face that is also set forward and pedimented. The roofs are hipped, and there is a central timber clocktower with a clock and windvane.

Inside, a lobby from the entrance leads to an octagonal domed circulation area with doors facing the cardinal directions and blind doors at the angles, all adorned with architraves. A central corridor provides access to offices in the wings, some of which feature eight-panelled doors. The north-west wing contains a conference room. This building is significant as the first in Britain dedicated to the development of chemical warfare, under the command of Lieutenant Colonel A.W. Crossley CMG, CBE, LLD, FRS, RE. The Old Chemistry Building, built in 1922, and the Old Physics Building, which served as the first laboratories, still exist as utilitarian stores but are not of special interest.