A rectangular room, measuring c. 4.20m wide N-S by in excess of 8.70m long E-W (its eastern end not seen), lay to the northside of the Infirmary Cloister, to the east of the dormitory undercroft and immediately south of the pentice covered passage. Access into the room was via a doorway in the north wall leading in from the covered passage. Remains of an enclosed stairway engaged within the north wall indicated access to an upper storey, as did the presence of a further enclosed stairway abutting the south wall, located in the north-west corner of what was later to become the infirmary cloister. The building was largely completed in the later part of the 12th century. Throughout the late 12th and early 13th century access from the upper floor down to the open garth was via an enclosed stairway, in the mid 13th century this structure was demolished, and it is not known whether access was into the infirmary cloister was retained to the east beyond the excavated area.

The identification of the room is uncertain, its position suggests that it may possibly have been the infirmary hall or refectory. However the evidence for a possible second storey makes this assumption difficult because rooms serving these functions were normally open to the roof. Alternative use of the room could be for administrative purposes such as a depository for the episcopal records and the priory accounts (treasury), however the busy thoroughfare caused by the stairways leaves this alternative as unlikely also. The other possibility is that the ground floor chamber was a Day Room for the inhabitants of the infirmary to meet and talk freely, with perhaps the infirmary hall being placed on the east side of the cloister.

The structure was mostly dismantled at the Dissolution c. 1538.

Hicks, M., 1989, 'St. Gregory's Priory: The Church and Conventual Buildings' (Article in serial). SKE30366.

Hicks, A. & Hicks, M., 2001, St. Gregory's Priory, Northgate, Canterbury, Excavations 1988-1991 (Monograph). SKE30367.