The updated British Standard (BS) 4142 guidelines that determine potential noise impacts on residential areas have in effect been updated and extended to explicitly cover more situations.

Nicholas Jones

Historically, these guidelines were intended to cover industrial plant and associated noise stemming from industrial premises. This has been extended to more clearly cover servicing and deliveries, so non-industrial premises including shops, hotels and offices will now be covered.

But while they have been expanded to consider more elements, the assessment criterion for ‘low impact’ noise has become open to interpretation and could be more relaxed than the previous standard.

The guidelines are not designed to assess the likelihood of noise nuisance, only the noise impact. The distinction between the two is important, as an adverse noise impact does not necessarily guarantee complaints and a complaint does not always verify an adverse noise impact.

There is, however, a danger that a more open definition of a ‘low impact’ could lead to legal squabbles, pitting one consultant’s view against another’s. The new methodology gives greater scope to the assessor — whether a consultant or environmental health officer — to quantify the noise impact in the context of each particular environment, so assessment results could vary significantly.

So where will be affected? Industrial sites often involve noisy processes, servicing and deliveries and noisy external plant. But deliveries and plant also apply to offices and retail development.

The changes are likely to affect locations outside central London more, as councils’ standards within London boroughs are already more onerous than the new standard, due to the greater levels of commercial development close to residential areas.

The greater potential for discussions around noise impact, combined with the relaxed criteria, makes the new standard more aligned with the National Planning Policy Framework and its support for sustainable development.

This brings with it the possibility that higher levels of noise may be acceptable if supporting a specific purpose or wider benefit.

As local authorities are likely to adopt the updated standards and there is evidence the new standard is being incorporated into planning conditions, it makes sense to start thinking now about how these changes can be incorporated into ongoing portfolio management and new development.

Nicholas Jones is head of acoustics at Hilson Moran