The single most influential document behind UK air quality assessments for planning is being rewritten. Environmental Protection UK and the Institute of Air Quality Management (EPUK/IAQM) have confirmed that their land-use planning guidance — the framework consultants use to decide whether a development needs an assessment and how to judge its impact — is under a substantive 2026 update. If you are planning a scheme this year, it pays to understand where the guidance is heading.
This post explains what the current guidance does, why it is changing, and how to keep your air quality evidence robust while the new version is finalised.
Why the EPUK/IAQM guidance matters
When a planning authority asks whether a scheme needs an air quality assessment, the answer almost always traces back to the EPUK/IAQM document Land-Use Planning & Development Control: Planning for Air Quality. It provides the screening criteria that decide whether an assessment is required, the impact descriptors (negligible, slight, moderate, substantial) that translate modelled concentrations into planning language, and the approach to mitigation and “air quality neutral” design. Our explainer on the EPUK/IAQM planning guidance walks through how it is applied today.
The problem is age. The core planning-for-air-quality document dates from 2010 and predates a decade of change: tighter Environment Act 2021 targets for fine particulate matter (PM2.5), the shift to electric vehicles, updated Defra LAQM technical guidance, and a much stronger policy focus on health and exposure. A refresh is overdue.
What is changing in 2026
The IAQM has signalled a co-ordinated programme of updates during 2026, developed with EPUK and industry partners. Member consultation on an exposure draft of the revised planning guidance is anticipated in the second half of 2026, alongside parallel updates to the construction dust and odour guidance. While the final text is not yet published, the direction of travel is clear from the drivers behind it:
- Sharper focus on PM2.5. Expect closer alignment with the Environment Act interim and long-term PM2.5 targets, and more emphasis on reducing population exposure rather than only avoiding limit breaches. See our post on PM2.5 and the Environment Act targets.
- A changing traffic baseline. As the vehicle fleet electrifies, roadside nitrogen dioxide is falling, but non-exhaust particulates (brake, tyre and road wear) and combustion sources remain. Assessment methods are likely to reflect this shift.
- Clearer mitigation and air quality positive thinking. Building on London Plan Policy SI 1, expect firmer expectations on demonstrating benefit, not just avoiding harm — our air quality neutral guide covers the current position.
- Updated construction dust methods. A refresh of the dust assessment approach, following the 2024 revision, is also in train.
What applicants should do now
Guidance in transition creates uncertainty, but a few principles keep your evidence durable. First, engage early: a screening assessment at the design stage tells you whether a full assessment is likely and lets you build in mitigation cheaply. Second, use the current published guidance and the latest Defra background maps — assessments are judged against the framework in force when submitted, not a draft. Third, design for lower exposure from the outset: set habitable rooms and ventilation intakes away from busy roads, avoid basement bedrooms next to traffic, and specify low-emission heating. These measures satisfy today’s tests and will almost certainly satisfy tomorrow’s.
It also helps to know the fundamentals that will not change: the pollutants planners care about (NO₂, PM10, PM2.5 and NOx), and what an Air Quality Management Area means for your site. Our overview of what an air quality assessment is is a good starting point.
Screening: when a full assessment is not needed
One of the most useful functions of the EPUK/IAQM guidance is telling you when you do not need a detailed study. The screening criteria consider the scale of development, whether it introduces new sensitive receptors (homes, schools, care settings) into an area of poor air quality, and whether it materially increases traffic or introduces combustion plant. A modest extension well away from an Air Quality Management Area will often screen out with a brief air quality statement, while a new-build near a busy junction or inside an AQMA is likely to need full dispersion modelling. The forthcoming 2026 revision is expected to keep this tiered approach but sharpen the exposure-based triggers, so understanding your site’s baseline early — using Defra background maps and local monitoring — remains the smartest first move regardless of which version of the guidance is in force when you submit.
How Fortress Associates can help
Fortress Associates produces automated air quality assessments for UK planning applications, free of charge and ready in minutes, using live official datasets at the moment of creation — Defra background concentration maps, national AQMA boundaries, monitoring data and DfT traffic counts. Our reports follow EPUK/IAQM criteria, IAQM dust guidance (v2.2, 2024), Defra LAQM.TG(22) and the NPPF, covering every UK local authority. We track guidance changes so your assessment reflects current best practice. Get in touch or browse our planning services to see how we can support your application.
Sources & further reading
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