Acoustics case study

Sir William Henry Bragg Building (Leeds University)

Background

The building was designed explicitly in terms of its acoustic performance, to create a world class facility housing some of the most advanced electroscope technology in the UK. SRL won the Association of Noise Consultants’ Building Acoustics Award for our work on this project. The new facility enables researchers to see and video the motion of individual molecules. Expert and detailed acoustic design advice provided has enabled the client’s requirements to be realised in full and help researchers continue their ground-breaking work.

Challenge

The Bragg Building is located close to noise sensitive receptors including existing university buildings and residential buildings. A planning condition was attached to the development which required noise from mechanical plant to be limited to 5dBA below background noise levels at the nearest noise sensitive receptors with the measurements and assessment made in accordance with BS4142.

The Bragg Building is a working University building so the control of noise and vibration had to be achieved without limiting the functionality for users in the other more traditional teaching areas and laboratory spaces.

Solution

We calculated the cumulative environmental noise emissions from all building services plant associated with the new building. Using manufacturer’s data for plant noise levels, attenuation performance data and plant layout drawings we created a 3D noise propagation model to predict noise levels from the proposed plant at the various noise sensitive receptors.

The smallest movements in the structure have the potential to affect the equipment within the building and so every single source of noise and vibration had to be considered in detail. This included isolation of all mechanical services plant and reduced airborne noise from mechanical services (to avoid erroneous air movement affecting test samples).