The project is an imaginative fusion of the original buildings, where large-scale scenery for theatres was painted, with new construction. This generated a close rapport between us as engineers and conservation advisors and the architect, Caruso St John. The Engineering is subtle and understated.
The structure is a free-standing steel frame with composite metal deck floors, sitting inside brick walls. In the case of the existing buildings the walls were the original listed masonry. For the new buildings the frame was wrapped in an engineered one-brick thick solid masonry skin, insulated internally, built with lime mortar and without joints.
The finished concrete floors are a striking feature of this project, designed as reinforced concrete topping slabs separated from the structural slabs by an acoustic layer and slip membrane, allowing them to shrink without cracking. The absence of cracking in these finishes is a direct result of the engineering care that went into their detailing.
The elliptical stairs were designed as a drum of loadbearing brickwork incorporating an engineered precast concrete handrail. The stairs themselves are of engineered timber.
The project was awarded the Stirling Prize 2016.