Noise Sensitive Developments and BS8233 Assessments
A noise sensitive development is classed as any form of development that could potentially be adversely impacted by noise. Typical noise sensitive developments are residential dwellings and offices.
During the planning application process for a noise sensitive development such as a residential development generally, if the development site is located in an urban or semi-urban area or located next to static transport links the local planning authority will request a BS8233:2014 assessment and sound insulation scheme. This form of assessment ensures that the external noise breaking into the proposed development falls within acceptable limits to ensure the amenity of future residents can be protected.
BS8233:2014 Overview
British Standard 8233:2014 - Guidance on sound insulation and noise reduction in buildings provides internal and external noise criteria that should be achieved within dwellings to ensure the amenity of the residents. The standard offers criteria for Bedrooms, Living rooms, and Dining Rooms as well as external amenity areas such as gardens. These criteria are based on the noise criteria outlined in the ‘World Health Organization's Guidelines on Community Noise’. An overview of the criteria is outlined below:
Day time
Bedrooms 35 dB LAeq,16hour
Living rooms 35 dB LAeq,16hour
Dining rooms 40 dB LAeq,16hour
Night time
Bedrooms 30 dB LAeq,8hour & 45 dB LAfmax,8hour
Garden Areas
50 - 55dB LAeq,16hour
It is generally accepted that should the internal noise levels within a dwelling fall within the above criteria then the amenity of the residents can be protected and suitable living conditions achieved.
Anonymous noise Vs Non Anonymous Noise
The above criteria are used for ‘anonymous’ noise sources such as transport noise from roads, railways or aircraft and are generally only applied to environmental noise that follows a diurnal pattern and is without specific character.
In an area where the surrounding noise is generated from industrial or commercial activity and/or entertainment venues, the above criteria may not be appropriate. Noise with specific character or features is generally arises from activity other than transport and is classed as ‘Non - anonymous’ noise. This means that a person or eternity can be attributed to the noise and thus can warrant a greater psychological response from any given listener. In this situation the criteria outlined in the table would need to be either modified or rating penalties applied to ensure the amity of any future residents can be protected.
Undertaking a BS8233 Assessment
Typically when undertaking a BS8233 Residential Noise Assessment the first stage would be to undertake a noise survey of the site for a long-term period, preferably 24 - 48 hours as a minimum.
Once the noise survey of the site has been undertaken the measured noise data is then analysed to establish the LAeq,16hour daytime noise levels, and the LAeq,8hour and LAFmax,8hour night time noise levels in the area.
A BS8233 noise break-in assessment can then be undertaken to establish the sound reduction that is required of all façade and roof elements of the proposed dwelling to ensure the BS8233 internal noise criteria can be achieved.
What is a sound insulation scheme?
The final stage of the assessment involves specifying a sound insulation scheme to ensure the noise breaking into the proposed development falls within the BS8233 internal noise criteria. This is to ensure the amenity of future residents can be fully protected. and satisfy the local planning authorities’ concerns.
A sound insulation scheme is a set of measures that need to be incorporated into the building design and generally include roof and façade sound insulation specifications as well as glazing and ventilation sound insulation specifications. The detailed specification of a sound insulation scheme should always be outlined as a result of a BS8233 assessment.
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