Six trial trenches (83m in total) excavated by Colchester Archaeological Trust in January 2007 (T1-T6) in the car park of the Adult Community College at Grey Friars demostrated the existence of medieval, post-medieval and possibly Roman archaeological features on the site, most of which are to be found at approximately 1m below modern ground-level. One piece of early Anglo-Saxon pottery (finds no. 27, F17, from the fill of a post-medieval ditch in T2) suggests occupation on or close to the site between the 5th and 7th centuries.

In T1, a 2.4m-wide medieval (mortared stone) wall foundation is likely to represent part of the friary church. To the north, there was a large amount of building rubble. A copper-alloy buckle typical of that worn on a monk's girdle came from this rubble. Three pieces of floor tile and four fragments of worked stone all point to a monastic building.

In T2 there was another medieval (or possibly Roman) wall foundation, at right-angles to that found in T1 and probably part of the same building or perhaps a cloister attached to the church. The layer of demolition debris sealing these features contained medieval and post-medieval material indicating that these buildings continued in use well after the Dissolution of 1538.

Further south, no foundations were exposed but there were two probable medieval sand-quarry pits (in T3 and T4). A linear spread of building rubble and a large pit filled with building rubble in T5 most likely derive from demolished friary buildings such as the church, cloister, precinct wall or the gatehouse.

Although no graves were exposed, one piece of human skull was found on the spoil heap of T3, which was probably already disturbed and out of its original context.

Activity following the Dissolution of the monastery is evidenced by spreads of building rubble in T2 which appear to have functioned as some kind of surface or walkway. Several other post-medieval pits and ditches were exposed.

The remains of a WW2 air-raid shelter (already demolished) was also exposed in T1, dating to the time of the site’s use as the County High School for Girls.