The new British Standard BS 8233:2014 providing guidance for the control of noise in and around both new and refurbished buildings applying for change of use has been updated to BS 8233:2014. Subsequent changes to the approved document resulting in changes to noise standards could impact on planning decisions. The new document provides recommended guideline values for internal noise levels within dwellings which are similar in scope to guideline values contained within the World Health Organisation Guidelines for Community Noise, 1999 (WHO). We have updated our noise survey reports to take into account the latest changes.
One of the main reasons for the change was the frustration with the 1999 version was that it contained two different degrees of acoustic quality, ‘good’ and ‘reasonable’. There was no consensus among Planning Authorities or acousticians as to which quality level was appropriate and, as a result, confusion and inconsistency reigned from one project to another.
The 2014 version of BS8223 removes the distinction between ‘good’ and ‘reasonable’ and recommends a single standard, which lies somewhere between the two previous standards. In some respects it’s a relaxation in criteria especially those in London, as the majority of London Planning Authorities adopted the ‘good’ standard within as their planning conditions.
The new standard also allows for a further relaxation in standards of up to 5dB where ‘development is considered necessary or desirable’. In view of current Government Policy towards supporting residential development, it is hard to see a situation where residential development would not be ‘necessary or desirable’. It will be interesting to see how Councils respond to this point with future decisions on projects when planning noise survey reports are handed in showing loud noise sources in close proximity.
We would expect that the many Councils will require the full standards to be achieved, with the 5dB ‘relaxation’ kept in reserve as a ‘safety margin’ in case of problems during construction, i.e. imposing the ‘good’ standard but accepting ‘reasonable’ standards at completion on the basis that the quality of workmanship may vary and manufacturer’s performance data is often optimistic as often highlighted in the different acoustic results between laboratory and onsite sound testing.
BS8233 2104 also brings the design criteria more into line with World Health Organisation guidelines. The changes in internal noise criteria are summarised in table 4 below.
Unlike the previous version, BS 8233:2014 doesn’t provide recommendations in relation to maximum noise levels in residential bedrooms at night from individual noise events such as vehicle pass-bys and train or aircraft movements. Instead, it advises that:
“regular individual noise events…can cause sleep disturbance. A guideline value may be set in terms of SEL (Sound Exposure Level) or LAmax,F depending on the character and number of events per night. Sporadic noise events could require separate values”.
The new guidance does, however still provide limited guidance for indoor noise levels from external noise events for hotel bedrooms, with a recommended indoor noise range of 45 – 55 dB LAmax.
BS 8233:2014 also adopts guideline external noise values provided in WHO for external amenity areas such as gardens and patios. The Standard states that it is “desirable” that the external noise does not exceed 50 dB LAeq,T with an upper guideline value of 55 dB LAeq,T whilst recognising that development in higher noise areas such as urban areas or those close to the transport network may require a compromise between elevated noise levels and other factors that determine if development in such areas is warranted. In such circumstances, the development should be designed to achieve the lowest practicable noise levels in external amenity areas by providing acoustic barriers etc.
We have undertaken many planning noise surveys in-line with BS 8233:2014 so you can rest assured our acoustic reports comply with the latest regulations.
If you are planning a new residential development and require a noise survey and/or guidance on sound insulation and noise reduction for buildings, please contact us at info@aptsountesting.co.uk or call Darren direct on: 02036 692650.
Alternately, if you require a noise survey and want to know more information on how you can prepare for the survey, please visit our Noise Survey Checklist page.