The judges said: "This is a complex and challenging project made to look rather effortless in practice. Quality and consistency of architectural thinking is evident throughout, and the building delivers an impressive and significant addition to the cityscape. This is an intelligent design and the architects’ success in delivering a great project on an extraordinarily constrained budget and programme is recognised and applauded by the jury."
Partner Andy Theobald also picked up RIBA South West Project Architect of the Year.
The project will now go on to the RIBA National Awards which are given to buildings across the UK recognised as having made significant contributions to architecture.