The Collyweston stone roof of the Great Hall at Christs College was showing signs that its useful life was coming to an end, and so with careful stripping and reclamation of the existing roof a large percentage of the stone tiles were incorporated in to the new covering. This allowed an opportunity to incorporate natural insulation into the roof space, carry out minor timber repairs and replace the lead box gutter to the rear of the parapet that was also tired. The Bell Tower structure was completely overhauled and strengthened, and a new lead covering with a hollow roll detail replaced the existing 160 year old lead work. The opportunity was also taken to redecorate the sundial to compliment other decoration within First Court.