Our brief was the acoustic design and commissioning of all acoustic aspects of a £62 million Millennium Landmark project incorporating the city’s main lending and reference library, an auditorium, forum, television and radio studios and electroacoustic systems.
The initial acoustic challenge was providing acoustics suitable for a modern library which is open-plan to the Forum, an “indoor town square” used as a public meeting, eating and circulation space and built of glass, steel and concrete. The tiled floors, glazed roof and a huge curved glazed screen were an irreversible part of the concept and in conjunction with the architect we had to design acoustic finishes compatible with this concept. At first floor level the library was effectively part of the Forum space, with only a part-height glass screen between the two. The Forum and first floor libraries therefore had to be considered as a single acoustic volume, and extensive computer modelling was used to assess the acoustics of each area as well as the level of noise transfer between them.
A further complication was the need for exposed concrete soffits for thermal stability in a theoretically low-energy building, preventing the use of standard acoustically absorbent ceilings in the library. We established that the acoustic absorption provided by the books alone would not be sufficient and we designed special acoustically absorbent elements built into furniture and wall finishes. We also designed special acoustically treated vents to allow natural stack effect ventilation while providing the required sound insulation of the building envelope, and partition head details to allow airflow between areas while maintaining acoustic separation.
Since completion of the library a large part of the building has been taken by the BBC for use as their regional television and radio broadcasting facility and Adrian James Acoustics have been appointed for the acoustic design and sound insulation of the studios and technical areas.
Client : Norfolk and Norwich Millennium Company
Architects : Michael Hopkins and Partners
Theatre Consultant : Michael Holden Associates
Project value : £62m
Completion : Library and Forum October 2001; Broadcasting Centre September 2002.
A Millennium Commission Landmark project