The string course continued around the south-east corner of the chapel and across its east end where it rose in stages over a four-light arched window. Below the string course on the south elevation are two, small ogee-arched lights, one to the west of the door and one between the first and second of the main windows. Above the string course and close to the west end of the chapel are two trefoil ogee-arched lights. This indicates that at this end the chapel had an upper floor. The extent of this is unknown, but it could not have extended further than the first of the main windows as it would have partly blocked it. The function of this small, upper room at the west end of the chapel is unclear. Fincham (1921, 263) has suggested that it may have been accommodation for the chaplain and cites parallels in the preceptory chapels at Poling, Swingfield and Godsfield. We know from the 1338 Extent that Chibburn did have a secular chaplain at that time. Access to this room was is unclear, but it would have been either from an external stair or directly from the main preceptory building if this and the chapel were contiguous structures. Access to the ground floor of the chapel from the courtyard was obtained through a pointed arched doorway in the north wall. The only original features surviving within the chapel are a piscina in the south wall and an aumbry in the south-east corner. However, Woodman (1860, 35-38) refers to the occasional discovery of human bones in the chapel and notes that a grave slab with a cross flory formed the threshold of the doorway into the stables, presumably the post-dissolution east range.
South-west corner of the chapel showing first-floor entry and rebuilding
Access to the upper room of the chapel from the main house was gained through a doorway inserted in to the rebuilt west wall of the chapel while in the south-west corner a further opening provided access to a garderobe. The stonework shows that this necessitated the partial rebuilding of the adjoining section of the chapel wall. Further openings in the north-east corner provided access to the upper and lower rooms of the newly built east range which also necessitated the rebuilding of this corner of the chapel.
With the dissolution of the monasteries and the suppression of the Hospitallers' Order in the 1530s the preceptory at Chibburn passed to the Widdrington family who proceded to demolish most of the buildings and convert the chapel to domestic use. This was accomplished by extending the floor of the chaplain's room to the full length of the range which necessitated the blocking of the main and east windows. Smaller, square opening were inserted into the blockings. On the upper floor the double ogee headed window was partly blocked and a three light mullioned window inserted further to the east. The south door was also blocked. Little survives of the north wall of the chapel but Wilson (1861) indentified several additional openings leading into the courtyard and a substantial fireplace that served both lower and upper rooms.