City Hall, London
Project summary
Sandy Brown Ltd was appointed in 2021 to provide acoustic consultancy services for the new City Hall project in Newham, London.
The original building (the Crystal), designed by WilkinsonEyre and Arup for Siemens, was opened in 2012 as an office and exhibition centre and achieved BREEAM Outstanding and LEED Platinum. A world’s first at the time. Sandy Brown provided acoustic design and consultancy services during the original construction.
The re-developed building provides a new headquarters for the Greater London Authority. In addition to office and meeting spaces, it contains a large triple height chamber for assembly meetings, large flexible committee room spaces, broadcast rooms, public forum / gallery spaces and a cafe.
We were appointed by the fit-out contractor during the post RIBA Stage 3 pre-construction phase to provide an independent review of the acoustic strategy. We then led the acoustic design through to completion.
Specific services provided by Sandy Brown included:
- Benchmark acoustic testing (at original building and existing GLA headquarters / City Hall)
- Audio demonstrations and presentations to the client and stakeholders
- Internal sound insulation design advice for all new and existing partitions
- Advice on acoustic finishes for the chamber, committee rooms and meeting rooms
- Mechanical services noise mitigation guidance for all spaces
- Review of contractor submissions and site inspections
- Acoustic testing in relation to BREEAM at completion.
Achieving the acoustic criteria within the constraints of the existing building presented significant design and construction challenges. Examples of this included:
- The inclusion of a mass barrier ceiling within the chamber to control noise break-in from aircraft serving City Airport.
- Development of suitable internal partition interfaces with an asymmetric double height facade and soffit to allow suitable deflection and maintain the project sound insulation criteria.
- Development of a self-supporting acoustic lid and appropriate partition interfaces to achieve high levels of sound insulation and acoustic privacy. This was necessary for meeting rooms located in the double height spaces where full height partitions and a robust soffit interface were not practicable.
- Achieving adequate crosstalk attenuation for underfloor supply ductwork and high level return openings within the rigid air pressure constraints of the system.
At completion, all BREEAM acoustic credits were achieved contributing to the Outstanding accreditation being retained.