St Andrew’s Cathedral and Chapter House are 19th-century buildings used by St Andrew’s Cathedral Primary and Secondary School (Sydney). The aging structure and facilities had become increasingly problematic to maintain so an overhaul was needed to bring the asset in line with current building and safety regulations. 

The client vision is to upgrade the Chapter House building and its atrium to modernise the facility for the school and public uses. The works include significant internal and external alterations and new steel framed fully glazed enclosing structure over the atrium. The brief required ACOR to minimise the impact on the Heritage fabric whilst satisfying the architectural requirements and client’s vision of the facility. 

ACOR approached the project brief with creative and unconventional designs, particularly for the atrium structure and the internal lift and staircases. The atrium structure is a tall but narrow frame that had to be designed completely independently of the existing structures which brought challenges from a lateral stability perspective. The architecture also required bespoke exposed steel elements which necessitated an innovative approach in designing the loads. 

The internal space was initially proposed to receive a number of heavy theatrical lightings and sound systems to be hung from the existing exposed timber roof and the additional loads would have required costly framing and support structures.  ACOR undertook a comprehensive structural assessment of the existing timber roof framing  to be able to understand the structural behaviour of the roof and identify its strength and weaknesses. Upon completion of this work, we were able to propose specific locations in the roof framing where equipment could be installed with no adverse effect on the timber structure. 

Date: July 31, 2020