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The misapplication of BS8233 1999 to offices in heavy industrial areas

Report by Mike Stigwood MIOA of MAS Environmental

Summary

Disproportionate weight appears to be given to the protection of office workers where the offices arc insufficiently designed for the nature and character of the area in which they are located. Offices in areas designated for major industry or commercial activity cannot expect the same freedom from noise as offices located in residential areas. They should be designed to protect against potential noise impact. BS8233 1999 is being erroneously applied as a control mechanism preventing noisy activities, regardless of the nature of the area where the offices are located, and whether they are suitably designed for noisy areas. They should not rely on window opening or other measures that are more appropriate to the provision of amenity to residential premises.

Introduction

Offices are generally treated as reasonably noise sensitive due to the nature of operations including telephone use, discussions, meetings and work requiring high levels of concentration.
The guidance in the BS is of a design standard directed at those providing new buildings and protecting the users of those buildings. Its title is Sound insulation and noise reduction for buildings - Code of practice. It provides design criteria for many building uses including offices. The criteria of the BS may be applied wherever the offices are located.
The foreword to the BS clearly describes it as a document primarily directed at providing new buildings and includes some advice on refurbishment of existing buildings. In the scope it states: "These criteria and limits are primarily intended to guide the design of new or refurbished buildings undergoing a change of use, rather than to assess the effect of changes in the external noise level."
It is not directed at the introduction of new noise sources into an existing noisy area. It is clear that expectations for freedom from noise will vary from area to area depending on the character of the area being considered. Anyone constructing offices ancillary to industry in a heavy industrial area should design those offices to be able to function with high levels of external noise and not rely on their absence. Where offices are constructed primarily in a residential area then there can be a higher expectation of freedom from loud external sources as this is dictated by residential amenity needs. As a consequence there is less need to design the office building to resist the passage of sound when in use.

Criterion
Reasonable conditions for study and work requiring concentration.

Typical situations Design range LAeqT
Cellular office40 - 50
Staff room35 - 45
Meeting room & Executive office35 - 40



There is clearly a need for offices in a range of localities which need to be designed to function having regard to the potential impacts likely in such areas. In summary, their design would need to vary to reflect the nature and character of the area in which they are constructed. It follows logically:

  • offices adjacent to major transport sources (airports and railways)

need to be designed to mitigate the noise from those sources

  • offices in a major shopping area / town centre will be affected by noise from people and advertising methods such as amplified music
  • offices in an area used primarily for entertainment such as pubs and clubs will be subject to patron and music / entertainment noise. These are less likely to conflict during the daytime but issues can arise
  • offices in rural localities may be subject to agricultural noise and more odour and flies etc while the latter two are not noise issues, they do impact upon design
  • offices in a heavy industrialised area will be subject to a range of pollutions including noise.


Increasingly office activity has been used as a reason to argue some industrial or polluting use is unsuitable in a particular locality despite the area being so designated. As a consequence noisy and polluting industry and entertainment activities are increasingly objected to as unacceptable because of their impact upon an office user, despite their location in a suitably designated area. In at least one case this has led to nuisance action. The industrial user chose to undertake noise mitigation measures rather than fight the matter as the costs were ultimately lower than the potential legal costs, win or lose.

BS8233 1999 is the benchmark most commonly used for arguing the unsuitability of a new noisy or polluting activity affecting offices. 'ibis is clearly a misuse of the standard and there cannot be a one size fits all" standard of acceptability in different areas. When BS8233 1999 is read carefully it is clear it is not promoting a single external criteria for all areas on which offices can be designed, it is merely identifying the criteria to be achieved internally to avoid communication and study issues.
The primary issue is therefore whether offices have been suitably designed and located for the nature and character of the area where they are situated. If they have been constructed on
the basis of the existing noise environment but that did not reflect the noise producing potential from an area, arguably the design is inadequate, rather than the new noisy activity being considered unsuitable.

This approach fits with nuisance law where people in towns and urban areas cannot expect the same freedom from pollution (e.g. odour, dust, smoke and noise etc) as those in rural locations'. The acceptability of any impact must relate to the character of the area within which it arises. This also follows human expectation. An office worker located in the middle of a heavy industrialised or major transport area would not expect the same freedom from noise compared to offices in the middle of a residential area. In turn the former would require design which adequately mitigates the noise but the latter could rely on openable windows for ventilation etc.

In attempting to impose control over internal office noise by restricting external noise and other pollutants, without adjusting for the character of the area is to ignore the needs of industry and commerce and to treat all areas the same way as you do a case of mixed industrial and residential conflict. There is no basis for such an approach and there must be expectation that in industrialised areas or those subject to other types of commercially based noise, more noise must be tolerated. In turn that means any office use in noisy and polluted areas should be designed to resist a higher passage of noise and pollution. In practice this means offices located in noisier areas need to be designed to operate with windows closed and include alternative means of ventilation.

It is difficult to address a location which may be subject to more noise in the future, depending on the neighbouring uses. The easiest way to address these differences is to rate areas according to typical character with the caveat there are always exceptions. This was originally done in ISO1996 and in the original BS4142 1967.

It is suggested an approach where the criteria to meet is adjusted for the character of the area is appropriate with use of +5dB in an urban area with some industry or commercial activity and +10dB in an area of heavy industry or solely entertainment / commercial (no residential). These are adjustments for expectation on the operator of an office to have to attenuate more noise than experienced in residential or mixed residential areas and follow the adjustments previously applied in former criteria such as ISO1996 which adjusted for the locality. In other words, where a proposal does not meet BS8233 1999 with the windows of the office open, an adjustment of 5-10dB is provided to account for the character of the area and the office operator needs to
design their office to provide a higher standard of attenuation as necessary.

1. There are situations where the reverse is true. Consider the presence of agricultural smells or flies in a rural locality compared to the same smell and flies in a heavily populated urban town. An expectation exists of rural smells and flies in agricultural areas which may not be tolerated and 'out of character' in towns and cities.

Photo Caption: Offices in noisy areas "must have different design"

Acoustics Bulletin September/October 2012

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