Background
Corney & Barrow Ltd planned a major refurbishment at their office building, 1 Thomas More Street, London E1W 1YU. The project included the installation of six new condensers, four Air Source Heat Pumps (ASHPs), a WC extract fan, and a Heat Recovery Unit (HRU) on the roof.
Given the building’s proximity to residential properties, a detailed noise impact assessment was required to support the planning application and ensure compliance with local authority noise policies.
Challenge
The key challenge was to ensure that noise emissions from the new plant installations would not adversely affect nearby noise-sensitive receptors, particularly residential windows and balconies approximately 30 metres from the site. The assessment needed to:
- Accurately evaluate existing background sound levels;
- Predict the cumulative noise impact of all proposed plant equipment;
- Recommend mitigation measures to ensure compliance with the London Borough of Tower Hamlets’ strict planning criteria, which require plant noise to be at least 10 dB below background levels at the nearest dwellings.
What We Did
We undertook a comprehensive approach:
- Background Noise Survey: Conducted continuous unattended sound measurements over six days to establish representative background noise levels, in line with BS 4142:2014+A1:2019 and local authority requirements;
- Noise Modelling: Developed a detailed 3D environmental noise model using Cadna/A software to predict cumulative noise breakout from all proposed plant items, factoring in site topography, building heights, and worst-case propagation conditions;
- Mitigation Design: Recommended specific mitigation measures, including:
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- Installation of in-duct attenuators for ducted systems, with defined minimum insertion loss values;
- Application of sound absorbent lining to the inner faces of the roof plant enclosure;
- Use of anti-vibration mounts and flexible connectors to control structure-borne noise and vibration.
- Compliance Assessment: Calculated predicted noise levels at the worst-affected residential receptor, ensuring all mitigation was included in the assessment.
Result
The assessment demonstrated that, with the recommended mitigation measures in place, noise levels from the proposed plant installations would be at least 10 dB below the existing background noise at the nearest residential properties. This fully complies with the London Borough of Tower Hamlets’ planning policy, ensuring no adverse impact on local residents’ amenity.
We concluded that the planning application should not be refused on the basis of noise, supporting a successful outcome for the client.
Project Progress
London Borough of Tower Hamlets granted permission for the development on 14th February 2025.
