Noise impact assessment for the replacement of heat rejection plant

The Italian Consulate chose Finch Consulting to prepare a noise impact assessment for the replacement of heat rejection plant at its office space in Central London. The noise assessment was required to ensure external mechanical ventilation plant was appropriately designed, so as to cause no disturbance at nearby noise sensitive locations.

Finch Consulting liaised with the Corporation of London’s Noise Team and agreed on an assessment approach in line with BS 4142:2014+A1:2019 “Methods for rating and assessing industrial and commercial sound”.

The assessment involved measuring existing background noise levels at a position that was representative of the typical noise climate outside the nearby most affected receptors. The plant noise impact was then modelled using noise prediction techniques to assess the likely impact of operational noise using the calculation procedures from ISO 9613-2:1996[1]

The assessment showed that an adverse effect at nearby receptors is only likely to occur sporadically during hot weather (when the heat rejection plant will operate at or near its maximum capacity) and that the typical noise impact will be low.

The assessment also reviewed potential mitigation measures to reduce the noise impact when the plant emitted the maximum noise output (as per the information received from the manufacturers). The mitigation measures were developed in conjunction with the plant manufacturer to ensure that these would not detrimentally affect the efficiency of the plant.

In order to ensure a speedy outcome, our client confirmed its willingness to install the proposed mitigation measures if planning permission was granted without delay. Indeed, following the submittal of our report, the local authority granted planning permission and our report was included within the permission (as it outlined the noise impact and provided construction details for the proposed mitigation) with a note that stated that “the development shall not be carried out other than in accordance with the following…document titled Plant noise impact assessment at Harp House, London by Finch Consulting, dated May 2021, ref 2217234”.

[1] “Acoustics – Attenuation of sound during propagation outdoors – Part 2: General method of calculation”.