National Planning Framework 4 - improving air quality outcomes: research

Research findings on improving air quality outcomes that will help inform policy development for National Planning Framework 4.

Executive Summary 

SLR Consulting Ltd was commissioned by Building Standards Division of the Scottish Government Directorate for Local Government and Communities on behalf of the Planning and Architecture Division to undertake a research project to investigate improving air quality outcomes of the anticipated National Planning Framework 4 (NPF4). The NPF4 will incorporate the current NPF3 and Scottish Planning Policy (SPP) into one document and be given development plan status.

The aim of the research project was to identify a series of conclusions around the types of air quality policy measures which are effective in managing potential air quality issues. These conclusions may be considered for inclusion within the NPF4 in the context of development plan policy and air quality across Scotland.

The project was undertaken in three Stages; referred to as Stage 1, Stage 2 and Stage 3 throughout. The main aims of each Stage are as follows:

  • Stage 1: to gain an understanding of the differing approaches to air quality within LDP. Scottish Local Development Plans (LDP) were reviewed to assess the level of representation of air quality.
  • Stage 2: to investigate approaches to air quality within planning in the UK as a whole and Europe as legal obligations and air quality standards are largely aligned.
  • Stage 3: to prepare a set of survey questions that could be used in a survey designed to further develop the conclusions of the research project based on practical experience of air quality and planning in Scotland. 

Stage 1 began with a detailed review of LDP in Scotland to identify the different approaches to managing air quality and the extent to which it is currently represented within LDP. Air quality was found to be represented in numerous ways: an air quality specific policy, directly within an alternative policy area and indirectly; where air quality was not specifically mentioned although known to be intrinsically linked to the policy area in question. It was noted that some LDP did not directly represent air quality at all and in these cases representation of air quality was very limited and would rely upon national planning policy.

LDP review identified 17 plans that had air quality specific policies. They were analysed in detail, and a scoring matrix was developed. Some of the policies scored better than others, in terms of their complexity, ideas incorporated and degree of integration with other policy areas. Integrated policies are considered more wide-reaching in their impacts and in air quality terms, more likely to provide the greatest air quality improvements that are sustainable.

Overall, NPF4 presents an opportunity to ensure air quality is consistently represented across Scotland.  A sufficiently prescriptive air quality specific policy could be included within NPF4. This policy could reference the need to assess air quality and the need for mitigation, removing the need for Local Planning Authorities to develop detailed air quality specific policies within their LDP unless necessary due to local factors. 

NPF4 could reference air quality within other policy areas, such as those relating to transport, placemaking and behavioural change. This would ensure that air quality has both a specific policy and is integrated with other policy areas.

Conclusions from Stage 1 include the following:

  • Linkages between air quality and other related topic areas should be made within NPF4, where possible, to promote integration of topic areas at the national level and also the local, LDP level; and
  • NPF4 has the opportunity to provide a sufficiently prescriptive air quality specific policy, removing the need for Local Planning Authorities to develop, within their respective LDP, detailed air quality specific policies unless necessary due to local factors.

Stage 2 built on Stage 1 to investigate approaches to air quality within planning in the UK and Europe. Firstly, a number of case studies of Scottish Local Planning Authorities were undertaken to further explore the representation of air quality within LDP (presented in Stage 1) and Local Air Quality Management (LAQM), and to understand the drivers behind the inclusion of air quality. The case studies also identified best practice approaches on the inclusion of air quality within LDPs.

In addition, air quality and planning guidance documents produced by Environmental Protection UK (EPUK) and the Institute of Air Quality Management (IAQM) and Environmental Protection Scotland (EPS) and the Royal Town Planning Institute (RTPI) Scotland were reviewed alongside Supplementary Guidance (SG) for air quality published in Scotland.

The planning regimes in England and Wales and their respective approaches to air quality was then reviewed. Stage 2 also referenced the recommendations of the National Institute of Health and Care Excellence (NICE) and Public Health England (PHE) on air quality and planning to illustrate the need for air quality to be considered within planning policy.

Finally, a review of European research projects on addressing air quality within development planning was undertaken. It focused on the more integrated approaches, considered to provide greater air quality improvements.

Conclusions from Stage 2 include the following:

  • The linkages between LDP and LAQM could be further realised and established by NPF4, for example; mentioning Air Quality Management Areas (AQMAs) could help provide consistency in their management within policy across Scotland;
  • NICE and PHE publications on air quality and planning reiterate the need for an integrated approach to spatial planning to improve the air quality outcomes of planning policy;
  • There are currently a number of European initiatives and resources to support integrated spatial planning for urban areas where air quality issues are the greatest. These are better considered at LDP level for urban Local Planning Authorities rather than incorporated within NPF4; and
  • The use of Air Quality and Planning guidance could be formally recognised at LDP level. NPF4 is an overarching planning policy and reference to specific guidance documents is not suitable considering that these can be updated more regularly than NPF4. Reference to ‘approved guidance/tools published by the Scottish Government’ is considered more appropriate. This would support the Planning (Scotland) Act provisions to remove the need for SG and streamline the approach to best practice across Scotland.

Stage 3 aimed to further develop the conclusions of the research project (Stages 1 and 2) by utilising the practical experience of air quality and planning in Scotland. A set of potential survey questions which could be included in a survey for Environmental Health Officers and Planning Officers in Scotland were produced. The survey would be aimed at professionals who work in the fields of air quality and planning and deal with the interactions between the two, e.g. Environmental Health Officers and Planners in Scotland.

The survey questions are based on the set of conclusions and best practice examples identified in Stages 1 and 2, with the aim of interrogating, strengthening and evidencing them further. The overarching aim of the survey would be to gain an understanding from professionals about the interaction of air quality and planning in Scotland and inform the focus of NPF4 in terms of air quality and development planning.

Overall the research project investigated ways to improve air quality outcomes of the anticipated NPF4. It reviewed current approaches within planning in Scotland in regards to air quality, identified best practice examples from the UK as well as European examples. The review identified that the most effective policy measures to improve the air quality outcomes of the NPF4 involve a prescriptive air quality specific policy detailing the approach to assessments as well as integrated policy measures with other policy areas such as transport and placemaking. 



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