Noise Impact Assessment for a large-scale Residential Development
Our Client, a major residential developer, approached Finch Consulting in 2020 to provide a comprehensive noise impact assessment to support its proposals for a 100 dwelling development.
The development was a landscape led scheme located inside an Area of Outstanding Natural Beauty. Following an initial submission of a noise impact assessment by other noise consultants, the Local Authority raised concerns in relation to the absence of an assessment in the reporting in relation to environmental noise pollution due to helicopter flyovers from a nearby military base and industrial noise from a nearby Agriculture hire and sale of equipment and machinery business. The initial noise impact assessment only assessed the road traffic noise impact from the dual carriageway to the East.
The purpose of the planning system is to contribute to sustainable development. The environmental noise impacts have to be reviewed and analysed with reference to the relevant aims in the National Planning Policy Framework (NPPF) and the Local Plan. As per national policy, new developments should be prevented from being adversely affected by unacceptable levels of noise pollution. As per the framework, planning policies and decisions should ensure that noise impacts from new developments are mitigated and reduced to a minimum and also that they don’t give rise to significant adverse impacts on health and quality of life.
In order to undertake a robust noise impact assessment, our Acoustics Experts consulted with the environmental health department of the Local Authority in order to agree on the assessment methodology (i.e. on-site noise surveying, computer modelling, time and date of measurements, suitable assessment threshold criteria that would be commensurate with the aims in the NPPF and local plan etc). They also consulted with the nearby military base in order to obtain historical helicopter movements and identify suitable dates for on-site measurements (i.e. identify dates when a sufficient number of helicopters pass by near and above the site would be expected). They also liaised with the nearby business since its sporadic noise emissions could affect the future residents and therefore the proposals would also need to protect this business from any potential future complaints (as per the Agent of Change principle in the NPPF). Finally, our Experts consulted with the farmer that operated the farmland where the new development was proposed in order to ensure access to suitable measurement positions that would not affect the produce.
Due to the fact that the proposal was for 100 new dwellings, it was agreed with the Local Authority that the assessment of road traffic noise levels should comprise on-site road traffic noise measurements and modelling of the resultant pollution around the dwellings using 3D computer noise modelling where noise levels could be shown in a colour-coded map. An assessment that was missing from the original noise impact assessment report (that only dealt with the impact at the first row of dwellings nearest to the road).
The comprehensive assessment by Finch Consulting highlighted the presence of adverse noise impacts to future residents (either inside the dwellings or in private amenity areas) from existing noise sources, and a series of mitigation measures were proposed.
Working closely with the design team, we demonstrated that a timber noise barrier at the boundary with the main road will have a negligible benefit due to the required access from the site. In turn, the assessment promoted a design solution where a series of closely planted trees will be placed along the boundary, which will provide a psychological barrier to the noise source, and also attract birds with the benefits of positive sound scaping with the resultant birdsong.
Planning permission was granted for this development in December 2021 via a unanimous decision in a live, in-person and virtual blend of the planning committee.