Modifications were made internally to Buildings U, V, W and Y. Metalworking continued within Buildings U, W and Y, while Building V continued as a hall.
 

Phase 9.6 (late 15th to early 16th century)

To the east of the pits were two deposits (1990 and 2311) consisting of successive spreads of ash. An iron object (SF01517) from 2311 produced prolific hammerscale confirming that iron smithing was continuing within the northern room of Building U. Three further intercutting pits (1981, 2016 and 2033) were then dug on the eastern side of the room, removing the earlier screens passage between Buildings U and V (see Phase 9.4). These pits contained burnt building materials, ash and waste associated with metalworking and the most recent backfill contained pottery dating to the 16th century. One of the backfills also contained iron knife blade SF01005. The primary function of the pits was difficult to interpret; they may represent successive attempts to insert a large post on the eastern side of the building rather than being for rubbish disposal. Whatever the function of these features, their position suggests that the eastern wall of Building U had shifted to the east, taking in part of Building V at this point. Further small patches of ash and floor material sealed the backfilled pits.

In the southern room of Building U, the southern end of the large furnace construction cut (2458) (see Phase 9.5) was partially infilled (2340). This contained both iron and copper alloy working debris suggesting that this part of the building was being used for metalworking. Deposit 2340 also reveals the presence of a narrow flue leading to the furnace at the northern end of cut 2458. Butchery waste was part of the make up of deposit 2340, many of the bones being stained an intense green from the copper alloy within the context (see the environmental report).

Sealing 2340, on its eastern side, were several floor deposits (1798 and 2167) which contained iron and copper alloy metalworking debris. A use deposit (1766), consisting of burnt ashy residues, covered the floors and may be interpreted as material raked out from the furnace. A further series of floor and use deposits, comprising charcoal, burnt clay, brick and tile, lenses of sand and yellow clay, built up to the north of it. One of these contained copper alloy casting waste (SF00964) and mould fragments (SF00980). In the south-western corner of the southern room further floor and use deposits (including 2295 and 2310) were laid down. These deposits appeared cleaner than those to the east suggesting that perhaps the western part of the room was used for cleaner processes, such as finishing, whilst the eastern part was used for clearing out and dumping of the spent slag and fuel.

At the southern end of cut 2458 a new rubble and clay footing (2089–2090) was constructed. This may have supported either a post to prop up the southern wall of the building or the end of the bellows which would have been used in conjunction with the furnace.

As the screens passage was incorporated within Building U at this point, Building V became shorter and was renovated and re-organised internally. The western wall of the screens passage (see Phase 9.3) was removed and the ground levelled (including 1380, 1523 and 1550) to raise the ground surface within Building V. The material used contained metalworking waste as well as two dumped architectural fragments. The extent of the levelling material suggests that the southern wall of Building V was removed during the renovation work and reconstructed on a new ground surface rather than on a sill beam wall, perhaps on a slightly different alignment. A rubble post-pad (1827) and a post-hole (1606) may have been inserted whilst renovation work was undertaken, or may have been used to support the rebuilt southern wall.

A new central hearth (1373) was then constructed. To the south, several occupation deposits built up (including 1507). These sealed the backfill of post-hole 1606 suggesting that it had been removed by this time. A further post-hole (1503) then truncated the occupation deposits. It also had a short life span, being backfilled and sealed by a layer of crushed mould fragments, from the casting of copper alloy vessels.

Perhaps as part of the rebuilding of the southern wall of Building V, the exterior stairbase (see Phase 9.2) in the north-eastern corner of the yard area was removed. The footings were partially robbed and a series of levelling deposits (including 1776 and 1762) laid down. These contained pottery of the 15th century and iron smithing debris. Deposit 1762 may indicate the presence of a doorway in the south-eastern corner of the newly renovated building. A pit or large post-hole (1782) was then inserted, perhaps indicating the blocking of the doorway. The feature may have been part of a new exterior staircase framework, or a timber structure attached to the south side of Building V within the yard area.

To the west of this a series of dumps (including 1351) were laid down, adjacent to the southern side of Building V. A sequence of fragmentary floors (including 1262), a brick footing (1684), a rough burnt clay hearth (not on plan) and post-holes (including 1264 and 1322) were laid down, suggesting that some sort of building or structure had been erected on the western side of the yard area.

In Building W, the hearth and floors (see Phase 9.4) were mostly robbed out, and replaced with compacted rubble (1857). Several metalworking use deposits and floors (including 1728 and 2156) were then laid down. Floor 1728 contained an iron smithing punch (SF00900) (see the artefacts report) and lead alloy metalworking waste (SF00834). It extended to the south of Building W, suggesting the presence of a doorway. Three large circular post-holes (1629, 1634 and 1727) were then inserted. These had an unknown function, but perhaps indicate a rebuilding of Building W, and the insertion of a canopy to the south over the doorway.

A post-hole (2324) was inserted in the north-western corner of Building Y, perhaps to support the northern wall 2616. A series of metalworking waste deposits (including 1987 and 2083) accumulated within the building. These contained evidence for copper alloy working (SF01025) and a stone hone fragment (SF01572).

Phase 9.7 (early to mid 16th century)

On the eastern side of the northern room of Building U, a new partition wall consisting of stake-holes (1325, 1919, 1921, 1923, 1925, 1927, 1929 and 1931) was built. This defined a new north to south screen between Buildings U and V, and may suggest the reinsertion of the screens passage after the renovation of Building V.