Hayles and Howe were responsible for the removal, restoration and replacement of the decorative plaster work and the total renewal of all the ceilings. The Assembly Rooms consist of a suite of rooms arranged sequentially around a central octagonal vestibule. Designed as a pleasure resort for the brilliant social parade of leisure in the 18th Century. An epitome of the City of Bath itself. The rooms have seen many changes of fortune but were restored before the Second World War. The interior was destroyed by bombs in April 1942 but was restored again around 1960.

Unfortunately, the materials used in that work were incompatible. This led to delamination between the pricking up and floating coats. Virtually all of the ornamental plaster work and all the huge coved ceilings have been removed, restored and replaced, but using as much as 95% of the original decorative fibrous plaster embedded in the new work. As a result of the previous failures a careful check was made of all batches of materials to ensure its freshness.