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.

3. Stage 2 - Outcomes 


3.1 The aim of Stage 2 was to investigate approaches to air quality within planning in the UK and Europe as legal obligations and air quality standards are largely aligned. 

3.2 A number of case studies of Scottish Local Planning Authorities were undertaken to further explore the representation of air quality within LDPs (presented in Stage 1) and 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 and how these can inform the inclusion of air quality within NPF4.

3.3 The Stage 1 review of LDP policies was followed by a review of the air quality and planning guidance documents, widely used by Local Planning Authorities, as well as a review of Supplementary Guidance (SG) for air quality published in Scotland. A brief discussion on the application of Clean Air Zones (CAZ) and Low Emission Zones (LEZ) was also included, as they were considered one of the key measures in urban centres in addressing elevated air pollution levels. 

3.4 The wider research review considered the planning regimes in England and Wales and their approach to air quality in their planning frameworks. The review also referenced recommendations by 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 adequately within planning policy. 

3.5 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. 

Air Quality and Planning Guidance Documents

3.6 To further understand the approaches to air quality policy and management across Scotland, widely used guidance documents were reviewed and are referred to collectively as ‘Air Quality and Planning Guidance’. The guidance documents, although considered as best practice in relation to air quality and planning, are only part of wider set of best practice examples, discussed further as part of this project. Best practice in this context is defined as the approach which produces greater air quality improvements when compared to alternatives.

3.7 Scotland and other countries in the UK all have similar guidance documents which promote best practice in relation to air quality and the planning system and are widely used across the regions. Environmental Protection UK (EPUK) and the IAQM guidance Land-Use Planning & Development Control: Planning for Air Quality[11] was most recently updated in 2017 and contains principles that are applicable to the whole of the UK. Environmental Protection Scotland (EPS) and the Royal Town Planning Institute (RTPI) Scotland adapted the EPUK-IAQM guidance to make it Scotland-specific and produced Delivering Cleaner Air for Scotland – Development Planning & Development Management[12] in 2017. The IAQM has also published a Position Statement: Mitigation of Development Air Quality Impacts[13], detailing the approach to mitigation. This guidance states that air quality should be considered at the earliest stage of the planning process, including within local planning policy, to successfully prevent impacts and that priority should be given to preventing or avoiding air quality impacts before they occur.  A review of Scottish LDPs and SGs, discussed in detail in the following sections, found that the Air Quality and Planning Guidance documents are widely used across Scotland.

3.8 Both guidance documents stress the importance of sound LDP policies to ensure that air quality is a prime consideration within the planning system; and the role that LDPs have in working to reduce air pollution and exposure to air pollution. Specifically, regarding Scotland and as the planning system is plan-led, the EPS-RTPI Scotland guidance states that it is essential for LDPs to provide sufficient reference to air quality to enable its consideration as a material issue within planning and the determination of planning applications. In terms of influencing air quality outcomes, both documents promote collaboration between professionals and departments within an authority and the full integration of inputs from a wide range of policy areas. This concept of integration reverts back to earlier discussions within this project, and the idea that integrated policy approaches are likely to be more effective in achieving the desired policy outcomes.

3.9 The Air Quality and Planning Guidance outline when an air quality assessment may be required and include a matrix for determining the significance of predicted effects. The review of air quality policies within LDPs (Air Quality Policy – Scoring Matrix section) undertaken for the project identified a number of policies reflecting the guidance documents approach. The word ‘significant’ or ‘significance’ was found within 10 of the air quality specific policies (Language Analysis section) however, no approach was provided in defining significance. In addition, both guidance documents have been extensively referenced and used as the basis of SG documents produced by individual Local Planning Authorities.

3.10 The above guidance documents contain in their majority the relevant information required to inform air quality specific policies, both in terms of air quality assessments and assessing significance, however, this could be better utilised in LDPs. They provide the air quality assessment framework and mitigation strategies to complement the policy objectives set out in national planning policy, both in England (NPPF) and Scotland. As suggested in Stage 1, official recognition of this guidance at the LDP level could be useful to ensure a common approach across Scotland.

Air Quality Supplementary Guidance

3.11 The review of SG was driven in part to provide context to the case study work but also to investigate the contrasting viewpoints that exist within the CAFS Independent Review and the Planning (Scotland) Act[14]. Specifically, recommendation ‘T9: Make Supplementary Planning Guidance on Air Quality mandatory’ listed within the CAFS Independent Review and the Planning (Scotland) Act provision to remove the statutory SG from legislation to ensure that policies are more clearly integrated within development plans. However, it should be noted that non-statutory SG could still be produced by the Local Planning Authority.

3.12 SG is detailed guidance on a specific topic area, and can be air quality specific, which expands on and provides details on the implementation of LDP policies and proposals. In the context of air quality, SG usually contain information specific to the Local Planning Authority and also general guidelines for completing air quality assessments, assessing the significance of predicted effects and mitigation that may be required to address any adverse effects.

3.13 The Scottish Local Planning Authorities found to have air quality SG are listed below, and the SG is noted as statutory or non-statutory:

  • Aberdeen City Council – Topic Area 5: Transport, air quality & noise (statutory);
  • Dundee City Council – Air Quality and Land Use Planning (statutory);
  • East Dunbartonshire Council – Air Quality Planning Guidance (statutory);
  • Fife Council – Low Carbon Fife: Section 4 Air Quality Development Guidelines (statutory);
  • Glasgow City Council – Air Quality and Planning Guidance (non-statutory);
  • Perth and Kinross Council – Air Quality and Planning (statutory); and
  • West Lothian Council – Air Quality (non-statutory).

3.14 All of the SG listed above make reference to air quality and planning guidance, this being either EPUK-IAQM guidance or EPS-RTPI Scotland guidance detailed in the previous section. This implies that specific air quality SG documents might not be required. Whilst air quality SG can be specific to the Local Planning Authority area, the bulk of information, including criteria for when an air quality assessment is required and assessing significance of predicted effects, is usually generic and sourced from the Air Quality and Planning Guidance. 

3.15 It is worth noting that a number of SG in England, not reviewed as part of this project, include a detailed approach in undertaking emission assessments for medium/major developments. This involves assigning a monetary value to air quality effects from development proposals, otherwise referred to as a ‘damage-cost’ calculation. The costs calculated are used to identify whether the proposed mitigation is adequate and if required identify the cost of any additional mitigation needed. The air quality specific SG in Scotland, listed above, do not reference the need to undertake an emission assessment. 

3.16 The Air Quality and Planning Guidance remit does not currently cover emission assessments. An update on the approach to Air Quality damage cost was published by Defra in 2019[15], designed to assess different policy options rather than individual development proposals. This approach has been applied by English Local Planning Authorities to assess development proposals. As the damage cost approach has not been formally recommended by IAQM or Defra for use in assigning damage costs from pollution on individual projects and considering it has only been applied to major projects, it is not considered relevant or appropriate for consideration in the NPF4. 

3.17 Based on the above, the CAFS Independent Review recommendation ‘T9: Make Supplementary Planning Guidance on Air Quality mandatory’ places an unnecessary burden on Local Planning Authorities to produce air quality SG when other guidance documents already exist for a similar purpose. In addition, as the Planning (Scotland) Act removes statutory supplementary guidance, recognition of the recommended use of Air Quality and Planning Guidance documents at the LDP level could be considered sufficient. 

A Review of Practice – Scotland Case Studies

3.18 Through the review of Scottish LDPs, it became clear that there were different approaches to managing air quality and the scale at which air quality was represented within LDPs varied. On one hand, some had air quality specific policies and/or integrated with other policy areas. Whereas, some only mentioned air quality indirectly. To understand the potential reasoning for the different approaches and to assess them further, it was appropriate to consider the LAQM context (e.g. whether AQMA’s were present) alongside the LDP.

3.19 Local Planning Authorities, under the requirements of the LAQM framework, are required to review and assess air quality within their administrative area. The air quality work undertaken by local authorities varies and in order to fully understand the complexity of the different approaches a series of case studies were undertaken. The case study work aims to provide best practice examples and identify the varying degrees by which air quality is considered with the planning system in light of the requirements set by the LAQM framework. 

3.20 In addition, the CAFS Strategy Review[16] recognises that there is progress to be made in SPP and local policy in order to achieve a fully cohesive system. To understand and enable such a system, it is important to understand the action Local Planning Authorities are taking at present, and the respective drivers for this; which involves the consideration of LAQM.

3.21 In terms of air quality, this involves several factors from both LDP and LAQM which include:

  • The land use of the area (e.g. urban, rural, mountainous or coastal);
  • Relating to the above; the size, population and sources of pollution;
  • Air quality specific LDP policies and others;
  • The presence or absence of AQMAs; and
  • How the LAQM process is actioned within the area.

3.22 Local Planning Authorities were chosen as case studies to explore links between LDP, LAQM and air quality further. Of the 32 Local Planning Authorities (the two National Park Authorities were excluded), reviewed as part of the research project, 14 of them had one or more AQMA declared within their administrative area at the time of writing. Of these 14 authorities with AQMAs, 10 had an air quality specific policy with their LDPs and 13 directly mentioned or linked to air quality within another LDP policy. 

3.23 The selection process was based not only on what was considered best practice, in line with published guidance and policy, but also to represent a cross section of rural and urban areas. This ensured that examples of Local Planning Authorities with varying degrees of air quality issues, or lack of issues, and varying representation of air quality within LDPs were considered. Table 3.23a summarises this exercise.

Table 3.23a: Summary of Case Studies

Glasgow City Council

  • No air quality specific policy although some direct representation of air quality within LDP
  • Air quality Supplementary Guidance
  • Largest Scottish city in terms of population (approximately 600,000)
  • 3 AQMAs

A review of the 2019 APR[17] found that during 2018 one automatic monitor and 7 diffusion tubes recorded exceedences of the NO2 annual mean standard; this was an improvement on 2017.

  • Proposals are ongoing to revoke two of the AQMAs.
  • Glasgow is the first of four Scottish cities to implement a Low Emission Zone (LEZ). The Glasgow LEZ is being implemented in two phases. The first phase from December 2018 targets buses and required 20% of bus journeys going through the city centre to be Euro VI compliant, with this target increasing by 20% each year. The second phase, from the end of 2022, will apply to all vehicle types; requiring petrol vehicles to be Euro 4 and diesel vehicles to be Euro 6/VI. LEZ aims to “accelerate the pace of improvement in Glasgow’s air quality”.
  • Glasgow City Council are investing heavily in public realm, cycle infrastructure and sustainable transport projects.
  • 93 EV charge points have been installed with 60 more planned for 2019/20 and a further 70 by 2020/21.
  • Implemented an ‘Energy and Carbon Masterplan’ with the aim of reducing carbon dioxide emissions by 30% by 2020.

Summary: Whilst the representation of air quality within the LDP is not extensive, the Council is implementing several air quality related measures, including a LEZ. Improvements in air quality have been noted as the Council intends to revoke two AQMAs.

Orkney Islands Council

  • No air quality specific policy or policies that directly link air quality
  • No AQMAs
  • Coastal / rural area, small population

A review of the 2019 APR[18] found that air quality monitoring data is at consistently low concentrations and below the air quality standards i.e. air quality is generally good.

  • The Council has a Carbon Management Plan and Green Travel Plan.
  • In the process of drafting a new EV and ULEV strategy.
  • Orkney Sustainable Energy Strategy 2017-2025 was published in 2017.
  • The second largest town of Stromness has a Low Carbon Travel and Transport (LCTT) project.

Summary: Air quality is not represented within the LDP, however there are no air quality issues within the Council’s area. Other strategies that link to air quality do exist.

North Lanarkshire Council

  • No air quality specific policy although small direct representation of air quality within LDP
  • Inland, east of Glasgow city and captures the outskirts
  • 4 AQMAs

A review of the 2019 APR[19] found that during 2018, two diffusion tubes recorded exceedences of the NO2 annual mean standard.

  • Intentions to revoke one AQMA.
  • Key projects include: an air quality awareness campaign ‘Choose Clean Air’, traffic management improvements at Chapelhall, funding towards active travel routes and input into projects, the ECO Stars fleet recognition scheme and improvements in the vehicle efficiency of the Council’s fleet.
  • The North Lanarkshire Council Carbon Management Plan 2019-2022 commits to a target reduction in emissions of 21% from the baseline year of 2015/16.

Summary: Air quality is not extensively addressed by LDP; however, the Council is implementing measures and improvements in air quality have been noted by the intentions to revoke one of the four AQMAs.

Moray Council

  • No air quality specific policy although some direct representation of air quality within LDP
  • Rural and partially coastal
  • No AQMAs

A review of the 2019 APR[20] found that no specific air quality issues have been identified and no exceedences of the air quality standards were noted for the 5-year period 2014 to 2018.

  • The Moray Council Active Travel Strategy 2016-2021 sets to encourage more non-motorised travel.
  • The Second Moray Local Transport Strategy (MLTS2) covers 7 topics: active travel, public transport, ports and harbours, roads, freight transport, travel behaviour and traffic management.
  • Aim to achieve Greenhouse Gas (GHG) emission reduction of 35% by 2030, compared to a 2005 baseline year.
  • Monitor traffic flows and air quality in tandem; recognising the relationship between them.

Summary: Air quality is not extensively addressed by LDP however no air quality issues are noted. Wider Council strategies incorporate goals relating to air quality.

Falkirk Council

  • Specific air quality policy and other direct representation within LDP
  • Contains industrial and urban areas
  • 4 AQMAs (one of which is declared for industry)

A review of the 2019 APR[21] found that during 2018, one diffusion tube measured NO2 concentrations above the annual mean standard, and there were two potential exceedences of the PM2.5 annual mean standard (although this was estimated from PM10 levels).

  • AQMAs are under review for revocation.
  • There are now over 40 EV charging points in the Falkirk Council area.
  • ECO Stars fleet recognition scheme now has over 200 members.
  • Falkirk Council has been working closely with the East Central Scotland Vehicle Emissions Partnership (ECSVEP) to work on the objectives set out within the CAFS.
  • Promoting air quality educational resources ‘Learn About Air’, and ‘Take the Right Route’ campaign which aims to promote active travel, car sharing and the use of public transport.
  • Investing in a £842,000 cycle and pedestrian bridge and have implemented Forth Bike electric hire scheme.
  • Council to undertake an industry modelling study to better understand and manage the industrial AQMA.

Summary: Air quality is well represented in LDP and the Council is implementing measures across a range of topic areas that influence air quality.

Inverclyde Council

  • Specific air quality policy and other direct representation within LDP
  • Mountainous and partially coastal
  • No AQMAs

A review of the 2019 APR[22] found that there have been no recorded exceedences of the air quality standards in the past five years.

  • Working with Strathclyde Partnership for Transport (SPT) to support projects which achieve reduced emissions from road traffic.
  • The target for reducing the Council’s carbon emissions is set at 16% by 2021/22 from a 2007/08 baseline year.
  • Promotion of active travel and public transport are detailed as key objectives.
  • Currently developing a new Cycling Action Plan and have released a Climate Change Plan.

Summary: Air quality is well represented in LDP, LAQM measures are limited however there are no reported air quality issues in the Council area.

3.24 Glasgow City Council has little direct representation of air quality within its LDP, (i.e. it does not have an air quality specific policy although air quality is directly mentioned within two other policies). There are current exceedences of the air quality standards within the city and the Council is taking action to address this with extensive air quality measures. Therefore, the lack of representation of air quality within the LDP does no25 Orkney Islands Council has no direct representation of air quality within its LDP; there is not an air quality specific policy and air quality is not mentioned within other LDP policies. However, the measured pollutant concentrations are consistently low, therefore suggesting that the Council does not have any air quality issues.

3.26 North Lanarkshire Council has some direct representation of air quality within its LDP (i.e. air quality is mentioned within one policy, although no air quality specific policy is included). The Council has four declared AQMAs and is implementing measures to improve local air quality. These measures seem to have had some success, as noted by the plans to potentially revoke one of the AQMAs. It would be difficult to assign any of this success to the influence of the LDP.

3.27 Moray Council has some direct representation of air quality within its LDP (i.e. air quality is mentioned within three policies, although there is not an air quality specific policy). There are not any specific air quality issues identified and measured air pollutant concentrations have been consistently below the relevant standards. This is most likely attributed to the Council area being largely rural with air quality issues from road transport mostly absent. Therefore, air quality issues cannot be directly linked to the LDP representation.

3.28 Falkirk Council has extensive representation of air quality within its LDP (i.e. it has an air quality specific policy and air quality is directly represented within four further policies). The Council has current and previous exceedences of the air quality standards and is implementing a variety of integrated measures. Therefore, in this example the representation of air quality within the LDP correlates to the presence of air quality issues and the presence of extensive action to improve local air quality.

3.29 Inverclyde Council has good representation of air quality within its LDP (i.e. it has an air quality specific policy and air quality is directly represented within one additional policy). However there are no recorded air quality issues within the Council area. Therefore, the representation of air quality within the LDP does not correlate to the presence of air quality issues. In addition, good air quality cannot be attributed to measures included in the LDP as the Council air pollution levels have been historically low.

3.30 The case studies presented, bar Falkirk, suggest that the degree of air quality representation within LDPs does not necessarily correlate with the level of action a Local Planning Authority is taking with the aim of improving air quality. In addition, positive air quality action within a Local Planning Authority cannot be credited to the LDP and planning system. The presence or absence of air quality issues within a Local Planning Authority area cannot be inferred by the representation of air quality within the LDP. It has not been possible to gauge whether the current, sometimes weak, relationships between LDP and LAQM have had a negative effect on the implementation of both frameworks  or whether this effect is negligible.

3.31 In summary, whilst there is potential for LDP and LAQM to interact and work in synergy to manage air quality, this is not currently realised within SPP and LDP or at the LAQM level. Reference to LAQM is absent from SPP, and the relationship between SPP, LDP and LAQM could be better established within NPF4. 

Clean Air Zones (England) and Low Emission Zones (Scotland)

3.32 Scotland’s four largest cities: Glasgow, Edinburgh, Aberdeen and Dundee have implemented or are due to implement a LEZ. The Transport (Scotland) Act 2019[23] provides the legal framework to create LEZs in Scotland, with their main aim centred around reducing emissions in the city regions and encouraging the use of alternative modes of transport to private vehicle use.

3.33 A LEZ bans certain higher emission vehicles from a central zone in a city. The criteria for entry are determined on Euro emission standards. Vehicles are subject to a fixed penalty notice if they drive through the zone and do not meet these criteria.

3.34 Similar to LEZ, several Local Authorities in England are due to implement CAZs and London has a live Ultra Low Emission Zone (ULEZ). The principles for CAZ implementation are set out within the Clean Air Zone Framework[24] and a CAZ would likely impose the same criteria as a LEZ on certain vehicle types, however entry to the zone is not banned only subject to a charge.

3.35 In line with the Transport Act 2000[25] for CAZs and the Transport (Scotland) Act 2019[26] for LEZs any excess revenue raised from charges and penalty fines respectively must be reinvested to support sustainable transport measures and the air quality objectives of the zones; therefore contributing towards action to improve air quality. The overall effectiveness of LEZ and CAZ has not yet had the opportunity to be realised and therefore their recommendation as best practice is not confirmed. 

English and Welsh Planning Frameworks 

3.36 The National Planning Policy Framework (NPPF) sets out England’s planning policy and has evolved from a series of Planning Policy Statements (PPS) and Planning Policy Guidance Notes (PPG) that were consolidated into a single and simplified document in 2012. The latest version of the NPPF was published in 2019. The NPPF considers air quality within several sections of text, these are partially reproduced in Table 3.36a.

Table 3.36a: England’s NPPF

(Paragraph 170-183 and Text)

170 Planning policies and decisions should contribute to and enhance the natural and local environment by:

e) preventing new and existing development from contributing to, being put at unacceptable risk from, or being adversely affected by, unacceptable levels of […] air […] pollution […]. Development should, wherever possible, help to improve local environmental conditions such as air […] quality […]

180 Planning policies and decisions should also ensure that new development is appropriate for its location taking into account the likely effects (including cumulative effects) of pollution on health, living conditions and the natural environment, as well as the potential sensitivity of the site or the wider area to impacts that could arise from the development

181 Planning policies and decisions should sustain and contribute towards compliance with relevant limit values or national objectives for pollutants, taking into account the presence of Air Quality Management Areas and Clean Air Zones, and the cumulative impacts from individual sites in local areas. Opportunities to improve air quality or mitigate impacts should be identified, such as through traffic and travel management, and green infrastructure provision and enhancement. So far as possible these opportunities should be considered at the plan-making stage, to ensure a strategic approach and limit the need for issues to be reconsidered when determining individual applications. Planning decisions should ensure that any new development in Air Quality Management Areas and Clean Air Zones is consistent with the local air quality action plan.

183 The focus of planning policies and decisions should be on whether proposed development is an acceptable use of land, rather than the control of processes or emissions (where these are subject to separate pollution control regimes). Planning decisions should assume that these regimes will operate effectively. Equally, where a planning decision has been made on a particular development, the planning issues should not be revisited through the permitting regimes operated by pollution control authorities.

3.37 The NPPF is accompanied by web based supporting Planning Practice Guidance (PPG) (updated November 2019) which includes guiding principles on how planning can take account of the impacts of new development on air quality. In regard to air quality, the PPG states:

“The Department for Environment, Food and Rural Affairs carries out an annual national assessment of air quality using modelling and monitoring to determine compliance with relevant Limit Values. It is important that the potential impact of new development on air quality is taken into account where the national assessment indicates that relevant limits have been exceeded or are near the limit, or where the need for emissions reductions has been identified.

Whether air quality is relevant to a planning decision will depend on the proposed development and its location. Concerns could arise if the development is likely to have an adverse effect on air quality in areas where it is already known to be poor, particularly if it could affect the implementation of air quality strategies and action plans and/or breach legal obligations (including those relating to the conservation of habitats and species). Air quality may also be a material consideration if the proposed development would be particularly sensitive to poor air quality in its vicinity.”

3.38 The PPG sets out the information that may be required within the context of a supporting air quality assessment, stating that:

“Assessments need to be proportionate to the nature and scale of development proposed and the potential impacts (taking into account existing air quality conditions), and because of this are likely to be locationally specific. The scope and content of supporting information is best discussed and agreed between the local planning authority and applicant before it is commissioned. It is not necessary for air quality assessments that support planning applications to duplicate aspects of air quality assessments that will be done as part of non-planning control regimes, such as under Environmental Permitting Regulations. 

[…] Mitigation options will need to be locationally specific, will depend on the proposed development and need to be proportionate to the likely impact. It is important that local planning authorities work with applicants to consider appropriate mitigation so as to ensure new development is appropriate for its location and unacceptable risks are prevented.”

3.39 The topic of air quality is clearly represented within the NPPF and PPG in England. The NPPF makes specific links between air quality and other policy areas, including; placemaking, traffic and travel management and green infrastructure. This represents an attempt to integrate topic areas and as discussed within Stage 1 this is thought to be more effective and wide-reaching in terms of improving air quality outcomes of planning policy. In addition, the NPPF makes reference to AQMAs and Clean Air Zones (CAZ) which presents an acknowledgement of LAQM.

3.40 In terms of statements and language, the NPPF and PPG both refer to compliance with ‘relevant Limit Values’ and ‘unacceptable levels’, however these terms are not necessarily determined or explained. As was the case with Scottish Policy reviewed in Stage 1, the lack of explanation within NPPF and PPG both suggest a reliance on other guidance, such as the EPUK-IAQM, for definition of such terms.

3.41 Similar to the NPPF for England, Planning Policy Wales (10th Edition) sets out the land use planning policies in Wales. The 10th Edition was published in December 2018 and contains Section 6.7 ‘Air Quality and Soundscape’ which includes air quality specific policies, these are presented in Table 3.41a.

Table 3.41a: Planning Policy Wales

(Paragraph 6.7.6, 6.7.10, 6.7.16 and Text)

6.7.6 In proposing new development, planning authorities and developers must, therefore:

  • address any implication arising as a result of its association with, or location within, air quality management areas, noise action planning priority areas or areas where there are sensitive receptors;
  • not create areas of poor air quality or inappropriate soundscape; and seek to incorporate measures which reduce overall exposure to air and noise pollution and create appropriate soundscape […]

6.7.10 It will be important to identify wider mitigation solutions to reduce air and noise pollution and to avoid exacerbating problems in existing air quality management areas or noise hotspots through the provision of green infrastructure identified as part of Green Infrastructure Assessments, by the provision of electric vehicle charging infrastructure or through promoting the need to consider effective design solutions. Planning authorities should work closely with bodies such as the Public Service Boards in the preparation of their well-being plans and seek input from their own Environmental Health departments.

6.7.16 Relevant considerations in making planning decisions for potentially polluting development are likely to include:

  • location, including the reasons for selecting the chosen site itself;
  • impact on health and amenity;
  • effect of pollution on the natural and built environment and the enjoyment of areas of landscape and historic and cultural value; […]
  • resilience, including where there may be cumulative impacts on air or water quality which may have adverse consequences for biodiversity and ecosystem resilience;
  • the risk and impact of potential pollution from the development, insofar as this might lead to the creation of, or worsen the situation in, an air quality management area, a noise action planning priority area or an area where there are sensitive receptors; […]

3.42 Planning Policy Wales takes account of air quality and addresses the implications that development may have on air pollution. It refers to AQMAs and like NPPF it therefore acknowledges LAQM. In addition, it presents some integration with other policy areas by referring to ‘green infrastructure’, ‘electric vehicle charging infrastructure’ and ‘design principles’. Placemaking principles and the correct siting of development are listed under the main considerations for planning decisions in terms of pollution. However, the policy is shared with ‘soundscape’ and references to pollution are generalised rather than specifically being focused on air pollution. This is considered to unnecessarily dilute the air quality policy.


3.43 The NICE Quality Standards (QS) are produced to set out “priority areas for quality improvement in health and social care”. QS 181 (refer to Appendix C for full text) covers air pollution from road traffic and health and is endorsed by the Department of Health and Social Care and supported by PHE. They are referenced here to demonstrate the need for air quality to be considered within planning.  

3.44 Quality statement 1 focus is on the use of LDP and local planning to address air pollution and provide the vision for managing air quality. It encourages collaboration between departments and key partners and suggests that the integration of policy areas, such as sustainable transport, are key to providing joined-up local action. Quality statement 2 focuses on road-transport-related pollution and how this can be influenced by decisions at the early planning stage relating to the correct placemaking. 

3.45 In terms of air pollution, planning policy and effective actions, QS 181 puts emphasis on the importance of integration across policy areas and the consideration of air quality issues at the earliest stage of the design and planning process. The quality standard provides some guidance for Local Planning Authorities in relation to planning policy, planning applications and best practice. Although improvements in air quality outcomes within the planning regime will be driven by obligations set out in the forthcoming NPF4, it is worth considering the NICE quality standards in the development of air quality policies within NPF4. 

3.46 PHE is the executive agency of the Department of Health and Social Care in England. They undertake evidence-based research and provide expertise and scientific support to the national and local Government in England. Public Health Scotland has been established as part of the public health reform programme in Scotland.

3.47 In 2019, PHE published the report Review of interventions to improve outdoor air quality and public health[27]. It details a hierarchy for the classification and prioritisation of air pollution interventions. Interventions are defined as ‘Prevention’, ‘Mitigation’ or ‘Avoidance’; with prevention measures being the first priority followed by mitigation measures then lastly avoidance measures. A prevention intervention would aim to reduce emissions before they have occurred, a mitigation intervention would aim to reduce concentrations once the emission has occurred, and avoidance interventions aim to reduce exposure to pollutants once in the environment.

3.48 Interventions from all three categories of the hierarchy are implemented throughout Planning Policy. For example, interventions relating to active travel may aim to prevent emissions by encouragement of modal shift and reduction in car travel, and interventions that consider green infrastructure and green networks may aim to mitigate environmental concentrations of pollutants.

3.49 The principles of the hierarchy resonate with the rationale of the NICE QS 181, in that prevention of air quality issues should be prioritised. This prevention would be expected from the early stages of the planning and design, as is stated within QS 181.

European Experience

3.50 This section provides a brief overview of approaches to air quality within planning at a European level. This is not intended to be an in depth and exhaustive review of European approach to air quality and planning which falls outside the remit of this research project. According to the European Union report ‘Spatial planning governance within EU policies and legislation and their relevance to the New Urban Agenda’[28]The competences for spatial planning lie on a national- or even sub-national or local level. The EU itself has no general competence assigned within this field. On the Member State level a wide variety of systems distributing the formal competences in spatial planning exists. These systems are rooted in national planning tradition and custom and differ significantly from each other.’ It is evident that the approaches to spatial planning across Europe vary significantly and therefore a degree of variation in the representation of air quality is expected. It is therefore unlikely that European examples will be directly applicable to the case of Scotland. 

3.51 This section has therefore focused on air quality relevant resources and solutions to assist in planning, identifying a number of integrated approaches in addressing air quality particularly in an urban setting. As the NPF4 remit is that of an overarching planning policy, the European examples appear to be more suited to inform the development of LDPs.

3.52 The EU has a number of relevant policy initiatives and research projects relating to integrated spatial planning. The Urban Agenda for the EU[29] is one such initiative which aims to improve the quality of life in urban areas through a balanced, sustainable and integrated approach. As part of this Urban Agenda, partnerships have been created to develop and implement tangible actions to tackle urban planning challenges. The initiative includes 12 partnerships, including Air Quality, Sustainable Use of Land and Nature-Based Solutions. 

3.53 The air quality partnership developed a number of online resources and training, including a code of practice for designing and implementing air quality plans, guidance on financing air quality plans for cities and local authorities and a training course on air quality and health. Therefore, there are resources to supplement the guidance, provided by the UK government and UK public institutions, that can be used by Local Planning Authorities in improving the air quality outcomes of their policies, including spatial planning in relation to air quality at LDP level. 

3.54 The Sustainable Use of Land and Nature-Based Solutions Partnership[30] focuses on the sustainable use of land and on the use of nature as one potential solution to current societal challenges, namely nature-based solutions (NBS). NBS are innovative solutions inspired by nature which aim to harness the properties and services of natural ecosystems to help build environmental resilience. NBS has the potential to be cost-effective whilst giving rise to a more resource efficient, competitive and greener economy. However, NBS should be integrated and designed-in with other mitigating actions for improving air quality as it is acknowledged that the air quality gains can be marginal[31].

3.55 Green infrastructure is a NBS commonly applied in an attempt to improve air quality, particularly in urban areas. The aim of the green infrastructure in this context would primarily be to reduce air pollutants by capture and deposition. Actions such as planting trees, building green roofs and green walls and maintaining existing green infrastructure also have co-benefits such as: microclimate regulation through shading, water retention and stormwater run-off mitigation, and noise insulation whilst positively contributing to amenity[32].

3.56 Barcelona has a strong commitment to urban green infrastructure as a NBS for managing air quality. With a population density of around 16,000 inhabitants per km2 it is one of Europe’s most dense and compact urban areas. Green space represents 36.8% of the city area in Barcelona. The city has developed several strategies and measures to address these via an integrated approach. In 2013, the ‘Green infrastructure and biodiversity plan to 2020’ was approved. It clearly links green infrastructure to provision of biodiversity and ecosystem services, including air quality. The plan puts forward measures such as: increasing street tree numbers, provision of more soil for street trees and an increase in city green spaces[33]. Barcelona presents a positive example of NBS being taken forward.

3.57 The report ‘Nature-Based Solutions and Re-Naturing Cities’ was produced by the Horizon 2020 Expert Group as part of the EU Research and Innovation policy agenda for NBS and identified several interventions that could contribute to a NBS for regulating air quality. However, the report notes that the suggested interventions have not necessarily been proved effective yet and more evidence is needed. The interventions, which relate to non-climate services, are categorised based on land use type and have been reproduced from the report in Table 3.57a.

Table 3.57a: Air Quality Regulation Interventions

Land Use: Forests
Intervention - Protect and expand forested area to absorb gaseous pollutants and trap particulates.

Land Use: Coastal areas
Intervention - Maintain vegetation in coastal wetlands, especially mangrove systems, to absorb gaseous pollutants and trap particulates.

Land Use: Agricultural land
Intervention - Plant shelter belts to absorb gaseous pollutants, intercept aerosols from pesticides and trap particulates.

Intervention - Use soil conservation measures (such as cover crops, wind breaks and minimum or conservation tillage) to reduce wind erosion and hence airborne particulates.

Land Use: Urban settings
Intervention - Protect urban green spaces, to absorb gaseous pollutants and trap particulates.
Plant trees alongside roads to trap particulates.

3.58 The above table focuses on several land uses and types, which could therefore be of relevance to Scotland. Whilst the above interventions are not tried and tested, they could be used as examples or starting points for NBS in Scotland. The brief examples presented above illustrate that such solutions are best incorporated within LDP rather than NPF4. 

Summary of Stage 2

3.59 As part of Stage 2 the linkages and potential correlations between LDP and LAQM were explored further. Overall, the correlation between the two was found to be weak; and the presence or absence of air quality issues could not be assumed by the presence or absence of LDP policies, and vice versa. The forthcoming NPF4 has the opportunity to sufficiently reference the LAQM framework and associated supporting tools, thus removing the need for individual Local Planning Authorities to develop specific air quality policies within the LDPs and produce SG. NPF4 could therefore potentially strengthen the relationship between LDP and LAQM, as presently the two systems do not necessarily work in synergy.

3.60 Conclusions from Stage 2 include the following:

  • The linkages between LDP and LAQM could be further realised and established by NPF4, for example; mentioning AQMAs could help provide consistency in their management within policy across Scotland; 
  • NICE and PHE publication 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.



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