Air quality statement or air quality assessment — which one does your planning application actually need? The two terms are often used interchangeably, but they are different documents: a statement is a short, largely qualitative screening report for low-risk schemes, while a full assessment is a detailed technical study that models how a development will affect local pollution. Submitting the wrong one is a common cause of validation delays and environmental health objections.
This guide explains what each document is, when councils ask for which, and how the screening criteria in national guidance decide the question for you.
What is an air quality statement?
An air quality statement (sometimes called a screening or qualitative air quality assessment) is a concise report for minor, low-risk development. It typically:
- describes the site, the proposal and the local air quality context — background pollutant concentrations, nearby monitoring, and whether the site sits in or near an Air Quality Management Area (AQMA) or smoke control area;
- screens the development against recognised criteria to show its traffic and emissions are too small to need detailed modelling;
- commits to sensible mitigation — for example electric vehicle charging, low-NOx heating and dust management during construction.
No dispersion modelling is involved, which keeps the document short and the cost low. For many householder and minor applications, this is all the council wants to see.
What is a full air quality assessment?
A full air quality assessment is a detailed, quantitative study. It predicts the development's impact on local concentrations of NO₂, PM10 and PM2.5 — the pollutants planners care about — during both construction and operation, and judges the significance of those impacts against the descriptors in EPUK/IAQM guidance. It usually includes:
- baseline monitoring or Defra background data for the site;
- traffic-based dispersion modelling of the completed development;
- a construction dust risk assessment following IAQM dust guidance;
- an assessment of whether new residents would be exposed to poor air quality (relevant where homes are proposed near busy roads);
- a mitigation package proportionate to the effects found.
Which one does your planning application need?
The decision usually follows the screening criteria in the EPUK/IAQM Planning for Air Quality guidance, which most environmental health officers apply. As a rule of thumb:
- A statement is normally enough for minor development outside an AQMA with little traffic generation — small residential schemes, modest extensions and changes of use with limited parking.
- A full assessment is normally required where the development is major, sits in or near an AQMA, generates significant traffic, introduces new residents close to busy roads, or includes combustion plant such as biomass or CHP.
Indicative triggers in the guidance include material increases in traffic flows on congested roads (with lower thresholds inside or near an AQMA), large car parks, new exposure close to heavily trafficked routes, and substantial demolition or earthworks. Councils translate these into their own validation checklists, so the same scheme can face different requirements in different districts — some authorities publish air quality supplementary planning documents that set explicit thresholds. Our guide on when an air quality assessment is required covers the triggers in more depth.
Does being in an AQMA change the answer?
Usually, yes. Inside or adjacent to an AQMA, councils apply stricter screening: schemes that would comfortably pass elsewhere often need at least a robust statement, and residential development frequently needs a full assessment demonstrating that future occupants will not be exposed to concentrations above the air quality objectives. If you are unsure of your site's status, our free AQMA checker will tell you in seconds. In London, Policy SI 1 adds the further requirement to be at least air quality neutral.
What does each report cost, and how long does it take?
Because a statement involves no modelling, it is significantly cheaper and faster than a full assessment — statements are typically a few hundred pounds from consultancies, while modelled assessments commonly run into the low thousands and take several weeks, with fees rising with scheme size and complexity. These figures are indicative; our breakdown of air quality assessment costs in the UK explains what drives the price. Getting the screening decision right first time is the cheapest step of all: a statement that should have been an assessment costs you a second commission and weeks of delay.
Key takeaways
- An air quality statement is a short screening report for minor, low-risk development; a full air quality assessment is a modelled technical study for larger or higher-risk schemes.
- The EPUK/IAQM screening criteria — applied through council validation lists — decide which you need.
- Sites in or near an AQMA face stricter screening and more often need the full assessment.
- Check your council's validation requirements before commissioning anything: submitting the wrong document is a leading cause of delay.
How Fortress Associates can help
Fortress Associates' automated air quality assessment service produces a free, site-specific report in minutes for any UK local authority, using live official data — Defra background concentration maps, national AQMA boundaries, monitoring network data and DfT traffic counts — and following EPUK/IAQM land-use planning criteria, IAQM dust guidance (v2.2, 2024) and Defra LAQM.TG(22). It screens your scheme the way an environmental health officer would, so you submit the right level of report first time. Contact us to discuss a complex site.
Sources & further reading
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