Ask anyone in our Aberdeen office whether the air conditioning system is loud and they will almost certainly say “no, not particularly”. Yet on the odd occasion when the system shuts down, the absence of the background whirring is deafening.

Noise, or the absence thereof, is a near constant in our life. We actively seek out noise at gigs, cinemas and stadia. We do our best to avoid it at home and at the office.

Despite this omnipresence, however, noise is often little more than an afterthought when it comes to planning a new development. “How” and “when” the issue of noise should be addressed are key questions for developers and planning authorities alike.

Answering these questions, however, is fraught with difficulties due to an inconsistent approach to what are acceptable noise levels. Recent appeal decisions reflect this inconsistency and it may be that further guidance from the Scottish Government on this issue is required.

Despite the issues surrounding acceptable noise levels, a longstanding and controversial planning and noise issue has recently received some overdue attention. The ‘Agent of Change’ principle which is now in force as a result of the Planning (Scotland) Act 2019 should provide much needed protection to our live music and cultural venues.

Whether it will be enough to halt further closures of these cherished institutions will, however, depend on planning authorities and developers’ willingness to consider the issue of noise from the outset of an application rather than wait for problems subsequently to develop.

Acceptable Noise Levels and How to Measure Them

Current national guidance and standards for the impact of noise on developments can be found in the Scottish Government’s Planning Advice Note (PAN) 1/2011 “Planning and Noise” and the accompanying Technical Advice Note (TAN) “Assessment of Noise”. Included in the TAN are a number of technical standards and codes of practice provided by authoritative organisations, such as the British Standards Institute and the World Health Organisation, to assist with determining acceptable noise levels.

Other guidance on noise levels can be found in various locations and several local authorities have adopted the recommendations of the Royal Environmental Health Institute of Scotland (REHIS) Briefing Note 17 “Noise Guidance for New Developments”. Often, however, these recommendations have been adopted with no formal consultation or adoption process.

Key to determining whether a proposed development includes measures sufficient to prevent unacceptable noise levels is how the noise levels will be measured. This includes whether noise levels are to be measured with windows open or closed. Guidance contained in the PAN and the REHIS Briefing Note differ as to when closed windows may be used to measure noise levels.

The PAN advises that alternative noise mitigation measures should be explored before closed windows with are utilised but does acknowledge that in some circumstances it may be unavoidable. The REHIS Briefing Note recommends the use of closed windows only in exceptional circumstances. This may not appear to be a substantial difference, but it has resulted in Reporters approaching the issue in different ways.

Two planning appeal decisions issued in 2019 by DPEA Reporters illustrate this clearly. Both decisions concerned proposed residential developments, one in Perth and Kinross and the other in North Lanarkshire, that were in the vicinity of major roads and would be impacted by the noise emanating from the traffic on these roads.

The proposed development in Perth and Kinross would be further impacted by the noise generated by a neighbouring potato processing factory. The North Lanarkshire appeal was allowed whereas the Perth and Kinross appeal was dismissed. While the proposed developments were in different local authority areas and faced different noise related problems, the issues in dispute were similar. Namely, should the developers be allowed to utilise closed windows with alternative ventilation systems in order to achieve acceptable noise levels?

In the North Lanarkshire decision, the Reporter noted the existing noise levels on the site and its proximity to a busy road as important local circumstances, and recognised that the Developer had explored “practicable mitigation solutions” before resorting to closed windows with alternative ventilation. All of this was deemed to be in keeping with the advice contained in the PAN and the appeal was granted by the Reporter.

In allowing the appeal, the Reporter noted that North Lanarkshire Council provided alternative guidance on noise, containing the recommendations of the REHIS Briefing Note. Explaining that this development would meet the “exceptional circumstances" requirement for the use of closed windows contained in the REHIS Briefing Note, the Reporter made clear that as the guidance was not part of the development plan less importance should be attached to it.

The Reporter in the Perth and Kinross appeal adopted a different approach to the issue of noise.  Acknowledging that the PAN does not absolutely require the use of open windows to achieve acceptable noise levels, the Reporter nonetheless concluded that the use of closed windows at the site was excessive and other forms of mitigation must be explored first. This was despite the developer designing the site with the noise caused by the road and factory in mind. The design included, among other mitigation measures, the use of bunds and acoustic fencing.

The Reporter considered the local circumstances of the site to be those of a countryside village and expected residents to be able to enjoy their properties as such, seemingly ignoring the existing noise levels of the site and cited the REHIS Briefing Note as relevant guidance. Dismissing the appeal, the Reporter also considered the need to safeguard the existing factory as a key employment site.

What we can see from the two decisions detailed above are the different but equally valid ways in which Reporters can approach the issues of noise and noise mitigation. In the North Lanarkshire appeal, the Reporter noted the existing noise levels as a factor in determining the local circumstances of the site, whereas in the Perth and Kinross appeal the Reporter looked to the nature of the development and surrounding area to identify the local circumstances, seemingly placing little importance on existing noise levels.

The REHIS Briefing Note was dealt with in different ways as well, with one placing little importance on it and the other citing it as important and valid guidance. While these different approaches create a degree of uncertainty for developers, what is clear is that developers should explore all noise mitigation measures before resorting to the closed windows approach in order to achieve acceptable noise levels.

By doing so, developers can demonstrate that they have considered the issue of noise thoroughly and have only resorted to the closed window approach where no alternative mitigation measure can achieve acceptable levels of noise.

Where further guidance may be required is in relation to the local circumstances of a site. Should Reporters and planning authorities consider existing noise levels on a site to be justification for the use of the closed windows approach or are they irrelevant in determining the nature of a site? Answering this question would provide developers with some assurance that when they propose a development for a noise sensitive site they know exactly what level of noise they are required to mitigate.

Agent of Change Principle

As mentioned above, the Perth and Kinross appeal decision referred to the need to safeguard the existing potato processing factory as an important employment site in determining the appeal.  This approach to existing noise sources, known as the ‘Agent of Change’ principle, is now national policy.

Introduced by the Planning (Scotland) Act 2019, the long campaigned for ‘Agent of Change’ principle is designed for, but not limited to, the protection of live music and cultural venues and puts the onus on developers of new, noise-sensitive properties to effectively deal with potentially problematic noise rather than curtail the existing sources of noise.

An attempt to safeguard live music and cultural venues, the principle requires planning authorities to “take particular account” of whether a proposed new development contains sufficient “measures to mitigate, minimise or manage the effect of noise” on the new development caused by an existing source of noise.

Furthermore, the changes brought in by the 2019 Act will prevent planning authorities from imposing on the existing noise source any “additional costs relating to acoustic design measures to mitigate, minimise or manage the effects of noise”.

These new provisions should not only help to halt the closures of Scotland’s live music and cultural venues but will also provide an extra degree of protection to noise generating businesses more generally.

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