Nevill Holt Opera is a new 400-seat opera performance space within the courtyard of a 17th Century Grade II* listed stable block. The challenge was to provide a sympathetic and elegant theatre in a very confined historic setting without damaging the old walls.
A 30m long underground duct, immediately adjacent to the existing foundations, runs past the orchestra pit and into an air plenum under the stalls. To avoid underpinning the existing walls, we developed careful sequencing for the construction of the orchestra pit that would retain walls and incorporate the duct route into the design of a stair to the side of the theatre.
The new theatre roof could not extend higher than the existing ridge line of the stable block. Simply supported, tapered, steel beams span the 15.6m width of the courtyard. The roof structure supports theatre rigging and a heavy wildflower green roof.
To get the support of the main beams onto the old walls without causing damage involved the removal of the Collyweston tiles and setting concrete padstones between the feet of the existing rafters and anchoring them to the old walls with grouted sock anchors. A steel spreader beam was set on top of the padstones and the steel columns that support the main roof beams were bolted to it.