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The Leys School in Cambridge has reduced noise with a ‘reflective acoustic barrier’.
The school’s all weather pitch has been in use by the school for over 20 years without complaint from neighbours; however when the school opened its doors to use of its sports facilities by outsiders, such as Cambridge Town Hockey Club’s training and matches, some neighbours expressed concerns about the noise. Keen to keep good relationships with its neighbours while equally wanting to keep letting in community users, the school commissioned an acoustic survey, by Cass Allen Associates, an acoustics consultancy firm.
The survey measured noise levels in the gardens of neighbouring properties while the sports facilities were in and out of use. That found the principal noise concerns stemmed from the impulsive and intermittent nature of the noise, rather than the absolute noise level – for example, the high frequency ‘clack’ sound as a hockey stick hits a ball or of the ball striking the boundary of the playing area – which draws attention to itself in a way that the dominant measured noise source, in this case, of distant traffic does not. Their report concluded that while noise levels were below what would be deemed acceptable, optional measures could be employed to reduce further noise migration.
In response to their client’s brief, architectural practice Cavaleri Partnership prepared a scheme to: redevelop the internal roadway around the school grounds, specifically alongside the sports facilities; regularise temporary parking; and make other changes for pupil safety and to reduce noise nuisance.
While not a direct requirement, but in line with the results of the acoustic survey, the school instructed its agent to submit an application that included the use of acoustic fencing to mitigate noise: from the sports facilities; the redeveloped roadway; and associated parking, which would also yield the incremental benefit of reducing head light pollution from the site.
Jacksons Fencing was appointed to design, deliver and install 227 metres of timber Jakoustic fencing. This features its tuning-fork posts and black powder coated steel spurs at 3.0 metres high along with associated access gates. The brief called for acoustic barriers to the all-weather pitch and roadway to effectively create an acoustic enclave, and for the boundary fencing alongside the roadway to maintain its height over undulating ground and also to accommodate a mature tree which was directly on the fence line.
The two zone acoustic solution is calculated to deliver a 10dBA (calculated through use of 3D modelling techniques (CADNA/A))reduction in noise measured in the middle of the gardens backing on to the sports facilities; in other words, the noise from the hockey pitch will be around 10dBA lower in the gardens relative to the other ambient noise sources in the area. Note that a 10dBA reduction in noise is a significant improvement and a measure generally accepted to represent a halving of subjective loudness. Visit www.jacksons-security.co.uk.