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.

1. Introduction


1.1 SLR Consulting Ltd was commissioned by Building Standards Division (BSD) of the Scottish Government Directorate for Local Government and Communities on behalf of the Planning and Architecture Division (PAD) to undertake a research project to investigate improving air quality outcomes of the anticipated National Planning Framework 4 (NPF4).

1.2 The Planning (Scotland) Act 2019[1] requires that the revised NPF considers any national strategy relevant to the improvement of air quality. Scottish Ministers plan to incorporate NPF3 and Scottish Planning Policy (SPP) into a single document to be known as the NPF4. This research project forms part of the development of the NPF4, expected to be laid before Scottish Parliament in Autumn 2021.

1.3 This research project builds on recent policy research, most notably the ‘Adoption of Scottish Planning Policy in Local Development Plans[2] that brought together details on all Local Development Plan (LDP) policies that are implementing SPP and ‘Cleaner Air for Scotland Strategy: Independent Review[3] that will form the basis for the revised Clean Air for Scotland (CAFS) strategy.

1.4 Air quality issues and their severity vary across Scotland reflecting the presence of urban centres and extensive rural areas. Although Scotland is performing relatively well in regard to air quality in EU terms, air quality will need to be adequately considered in development proposals to maintain the current downward trend in air pollutant concentrations. It will also enable future developments to be taken forwards in a manner that fulfils air quality policy, climate change and sustainability objectives.  

1.5 The aim of this research project is 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.


1.6 The planning system is underpinned by the current NPF and SPP. The NPF is the Scottish Government’s spatial strategy whereas the SPP sets out the national thematic planning policies that form the basis of development plan policy which in turn informs decisions on planning applications. Local Planning Authorities prepare LDPs that underpin decision making on planning applications. The NPF4 will incorporate the SPP and provide the NPF4 with development plan status, allowing it to be used by planning authorities in determining planning applications. The Planning (Scotland) Act 2019 requires that the NPF is prepared in a manner that contributes, among other outcomes, to improving health and well-being; and improving equality and eliminating discrimination.

1.7 The SPP references air quality in the Principal Policy on Sustainability, making it a material consideration in plan making and determining planning applications. However, it does not identify the aspects of land allocations or individual development proposals that will lead to improvements in air quality. According to the research project ‘Adoption of Scottish Planning Policy in Local Development Plans’, the current SPP does not provide the key principles/measures that can ensure that development plans and development management do not result in worsening of air quality. In addition, the ‘Cleaner Air for Scotland strategy: Independent Review’ makes a series of recommendations on air quality and planning. This research project builds on the outcomes of the above projects to provide recommendations in incorporating air quality considerations in planning policy, aiming to achieve synergies with other planning considerations such as sustainable transport and climate change.

1.8 This research project will focus on the following recommendations of the ‘Cleaner Air for Scotland strategy: Independent Review’:

  • T8: Spatial planning and transport planning need to work together to be effective in ensuring local decision-making does not undermine national objectives for air quality;
  • T9: Make Supplementary Planning Guidance on Air Quality mandatory;
  • P3: Local Authority Air Quality Performance Specifics and Knowledge Exchange; and
  • LG1: Realising effective Placemaking in practice.

1.9 In addition, where relevant, the relationship between Local Air Quality Management (LAQM) and local planning policy (i.e. LDP) is explored. Part IV of the Environment Act 1995[4] requires all Local Authorities within Scotland to periodically review and assess the quality of air within their administrative area.

1.10 Where any of the prescribed National Air Quality Standards are not being achieved, or not likely to be achieved, the authority concerned must designate an Air Quality Management Area (AQMA). For each AQMA the authority has a duty to draw up an Air Quality Action Plan (AQAP) setting out the measures the authority intends to introduce to deliver improvements in local air quality in pursuit of the standards. As such, Local Authorities have formal powers to influence air quality through a combination of LAQM and LDP; the two can therefore often be linked.

1.11 The Department for Environment, Food and Rural Affairs (Defra) and the Scottish Government has published technical guidance for use in LAQM work, referred to as LAQM.TG(16)[5]. Every year each Local Authority in Scotland must produce an Annual Progress Report (APR) detailing the current air quality of the area, monitoring undertaken and progress on AQAP measures. The APRs are available online through individual Local Planning Authority websites and are also published centrally on the Air Quality in Scotland website[6].

Aims and Objectives

1.12 The objectives of this project are:

  • Review the current approach to air quality in development planning.
  • Assess the current approach to improving air quality within the development planning framework through the review of literature and taking into consideration the independent review of the ‘Cleaner Air for Scotland strategy’. 
  • Identify whether current planning policy approaches are likely to be effective in managing air quality.
  • Investigate whether changes to planning policy could be made to improve air quality outcomes, considering the impact of behaviour change and place design for new and existing places.
  • Identify a series of conclusions surrounding the best practice approach for managing air quality and improvement of air quality outcomes. 

Its main aim is to make a series of conclusions regarding the types of air quality policy measures which are effective in managing potential air quality issues and of relevance to the NPF4 in the context of development planning policy.


1.13 The scope of the research project is presented in Table 1.12a below.

Table 1.12a: Scope

(Task and Description)

Inception meeting - Discuss scope and timeframe of the research project.

Stage 1 - Review the ‘Adoption of Scottish Planning Policy in Local Development Plan’ and associated excel ‘Database of Development Plan Policies’ for relevant air quality policies and assess their efficacy. Review the differing approaches to air quality across LDPs.

Stage 2 - Identify a set of best practice examples from Scotland and Internationally that could be used to inform NPF4 on the approaches which best manage air quality in the context of development plan policy.

Stage 3 - Prepare a set of questions to Environmental Health Officers and Planners to further inform the set of conclusions and best practice examples identified in Stages 1 and 2.

Reporting - Prepare a report to present the scope, methodology and outcomes of the research project.

1.14 The following paragraphs present the detailed methodology for Stages 1 to 3. 

Stage 1

1.15 The main aim of Stage 1 was to gain an understanding of the differing approaches to air quality within LDPs. Scotland’s LDPs were reviewed to assess the level of representation of air quality.

1.16 The review was driven by the ‘Cleaner Air for Scotland strategy: Independent Review’ recommendations. It extracted the air quality relevant information from the research review ‘Adoption of Scottish Planning Policy in Local Development Plans’ and associated excel ‘Database of Development Plan Policies’. The database was interrogated to identify the following:

  • Air quality specific policies (direct); and 
  • Sustainable transport/energy/climate change/health policies and any other policies that indirectly impact air quality.

1.17 A database of policies was created identifying the air quality specific policies and policies that indirectly infer air quality. The presence of AQMAs and relevant Supplementary Guidance (SG) as well as geographical classification (i.e. coastal, urban, rural, etc.) was included within the database. This provided an overview of the current approach to air quality within development plans.

1.18 The air quality specific policies were assessed qualitatively by undertaking a textual analysis, classifying the complexity of the policy and the degree in which it integrates with other LDP policies. In addition, the direct policies were analysed in relation to the language used. Common themes, phrases and words were noted throughout the policies.

1.19 Stage 1 provides an overview of air quality policies within LDPs to identify the varying approaches applied and identify current air quality policies that can be used as the basis of the development of air quality policies within NPF4.

Stage 2

1.20 As part of Stage 2 a review of approaches in Scotland in relation to air quality within planning was undertaken through a series of case studies, identifying a series of potential improvements in how air quality should be addressed within the NPF4. Stage 2 included a review of the published SG on air quality by Scottish Local Planning Authorities.

1.21 A wider literature review was conducted to identify best practice examples of effective approaches to improving air quality in a planning policy context. The key sources consulted were:

  • Published policy documents and frameworks;
  • Published guidance documents (i.e. IAQM); and 
  • Research reports and papers (i.e. European Commission research projects).

Stage 3

1.22 The main aim of Stage 3 was to prepare a set of 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. 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.

1.23 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.



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