Case Study - Lidl development, Hersham

Background

Stuart Michael Associates (SMA) was tasked with undertaking a noise assessment to examine both the constraints on, and the impacts of, a proposed Lidl store, with residential flats located directly above it. The site is located in Hersham, Surrey. The noise assessment investigated whether the proposed 38 residential apartments, which are situated above the Lidl store, would be negatively affected by nearby noise sources, including the local highway network, and commercial activities including the proposed Lidl store itself.

Action Taken

Measurements where undertaken on two separate days in January 2015- due to restricted access to the site it was not possible to measure the night time noise levels so a comparable site was used. To assess the constraints on development two methods were used: measuring sound levels adjacent to the development site and through calculating future years after opening (2016 – year of opening and 2021 – 5 years after opening). Calculations were achieved by modelling road traffic data for the local highway network and calculating the noise levels using the Government publication: ‘Calculation of Road Traffic Noise (CRTN) 1988’.

To assess the impact of construction an approximation was made as to what type of plant will be used for each phase. As there are a number of residential dwellings adjacent to the site, the potential impacts have been assessed at distances of 10 metres to 70 metres from the noise source to the sensitive receptor.

Findings

The noise assessment ascertained that at the location of the proposed residential development, noise levels were predicted to be below 55 dB during the daytime and below 45 dB during the night time. However façade noise levels at the proposed apartments (first floor, second and third floor levels) were predicted to be 60 dB or less during the daytime and 52 dB or less during the night time. As noise levels were above 50 dB during the daytime and above 45 dB during the night time, mitigation was recommended to achieve BS 8233:2014 internal noise levels

It was also calculated that impacts of the development generated traffic on noise levels at local sensitive receptors (existing housing developments) were predicted to have “Neutral” or “Slight” significance in the “Year of Opening” and also five years after the “Year of Opening”.

The noise assessment also highlighted mitigation for the effects of the construction noise process on the local sensitive receptors.

As such, based upon the SMA noise assessment, the Local Planning Authority concluded that noise was not a reason to withhold the granting of planning permission.