The following text is from the original listed building designation:
1. 944 BLACKFRIARS STREET (West Side)
The former Blackfriars Monastery TK 1458 SE 2/91 3,12.49.
II GV
2. C13 and later. 2 storeys flint faced with stone quoins. Restored tiled roof. Windows on the first floor are 4 double lancets with quatrefoil heads. Stone cills, The ground floor has mostly restored mullions. Porch with steps built on to first floor. Doors are 4 centred arches. The left side has an extension of 2 storeys in red brick of 1763 to 1764 on a stone base. Round-headed or plain casements having leaded lights C18 6 Panelled door. The ground floor has an undercroft with stone octagonal-sided columns and brick diagonal ribbed vaulting. Stone floor. Traces of timber framing within the red brick extension.
Forms a group with wall on right side of Blackfriars Monastery and the Monastery Guest House, St Peter's Lane.
Listing NGR: TR1488958066

From the 18C it was used as an Anabaptist (later Unitarian) meeting house until 1912. The building was restored in the 1920s and used as a store and was then bought by the Cleary Foundation before being given to King's School to be used as an art school and gallery in 1982.

English Heritage, List of Buildings of Special Architectural or Historic Interest (Map). SKE16160.