During this phase a new structure, Building U, was constructed on the western side of the excavation area, on the Walmgate street frontage. The building was used for metalworking.
 

A new building, Building U, was constructed in the north-west corner of the site. It measured c.9m long by 5–6m wide, with its long axis at right angles to the Walmgate street frontage. This building consisted of a workshop on the Walmgate street front c.4m x c.5m and a room behind measuring c.4.2m x c.6m. A possible levelled area to the rear of the property, over 3.2m x 3.5m in area, consisted of contexts 2653–2655. The new building was attached to the western side of Building S (see Phase 8) and is probably contemporaneous with the later activity within that building.

A number of levelling deposits, one of which showed signs of burning (2486), were laid down before the construction of Building U. The levelling material contained pottery dating to the 14th century, and was very likely redeposited. The new building utilised earlier walls 4005 (see Phase 7), 4058 and 4056 (see Phase 8) for its northern wall. To the east, the wall between Building U and Buildings S may have been removed by later activity, or may have utilised two post-holes 2393 and 2461 (see Phase 8); a small beam slot/gully (1739) extended the eastern wall of the building to the south. The southern wall of the building consisted of a sill beam wall of limestone fragments (2440) and the western wall was situated beyond the limit of excavation. Internally, a new limestone sill beam (2606) was built within a construction cut. This divided the building into two rooms.

Several internal post-construction levelling deposits or floors including 2425 and 2438 were laid down within Building U. A large edge-set tile hearth 2453 and 2472 was then constructed on the eastern side of the workshop at the north end of the building. It had an unusual tile-lined sunken feature, including context 2473, that may have been used for holding tools or crucibles during metalworking. Its irregular surfaces may, however, have made balancing a crucible perilous. Context 2473 contained a number of artefacts that may indicate ironworking, including a stone hone fragment (SF01430). It is thought likely that this was a metalworking workshop on the Walmgate street frontage. An internal slot (2550) was inserted to create a partition within the workshop and a use deposit (2408) was spread in a possible doorway between the workshop and the room to the south.

The western side of the edge-set tile hearth appears to have degraded rapidly and was repaired (2481), suggesting that this was the area most used during metalworking. Two levelling deposits (2184 and 2502) were laid down around the northern and western sides of the repaired hearth to deal with erosion of the floor surface. Environmental evidence from this phase was limited and cannot tell us anything about diet, hygiene or health at this time.