IAQM 2024 Dust Threshold Checker
A free quick-reference tool for planning consultants, developers and contractors to check whether your project requires a Dust Impact Assessment under the IAQM 2024 V2.2 guidance.
What This Checker Is For
The Institute of Air Quality Management (IAQM) published an updated V2.2 of the Land-Use Planning & Development Control: Planning for Air Quality guidance in January 2024. The update revised the site size thresholds that determine when a Dust Impact Assessment (DIA) is required to support a planning application.
The headline effect is that many developments which previously triggered a DIA no longer do under V2.2 — and in a few cases, sites that were below the older thresholds may now sit closer to the line. Use this checker as a free first-look reference to confirm whether your project is likely to require an assessment, and what level of detail the LPA will expect.
This is a quick reference, not a substitute for a professional assessment. If your site is close to any of the thresholds, or if sensitive receptors are nearby, get in touch — we'll review your project and give you a clear answer the same working day.
Check Your Project Against the V2.2 Thresholds
The IAQM guidance defines four dust-generating activities. If any one of them exceeds its threshold and sensitive receptors lie within the buffer distance, a DIA is likely required.
1. Demolition
Total volume of building(s) to be demolished, measured as gross internal volume in cubic metres.
Previously the trigger was >50,000 m³, so smaller demolition projects that historically required a detailed DIA may now sit below the line.
2. Earthworks
Total site area subject to earthworks — cut-and-fill, levelling, stripping of topsoil, large excavations.
The V2.2 update raised this dramatically (from >10,000 m²). Low-risk sites under 2,500 m² are screened out entirely.
3. Construction
Total floor area of new buildings to be constructed across all phases of the development.
This is the cumulative floor area trigger for the construction phase. Smaller schemes typically need only a screening note or a Dust Management Plan.
4. Trackout
HGV movements per day to/from the site travelling over unpaved or dust-bearing surfaces.
Or >50 outward HGV movements per day averaged across a 12-month construction period. Trackout is often missed for sites with paved access roads.
The IAQM 2024 Decision Tree
Five steps to determine whether your development needs a DIA, and what level of assessment is appropriate.
Identify the dust-generating activities on your site
Confirm which of the four activities (demolition, earthworks, construction, trackout) will take place — many sites involve more than one.
Check each activity against the V2.2 thresholds
Compare your site quantities to the thresholds above. Any single activity exceeding its trigger means the site is in scope for further screening.
Identify sensitive receptors within the buffer
Map all human receptors within 350 m, and ecological designations within 50 m, of the site boundary. No receptors in the buffer means no significant effect — even if thresholds are exceeded.
Assign a risk category for each activity and phase
Combine the dust emission magnitude (small/medium/large) with receptor sensitivity (low/medium/high) to give a risk category: negligible, low, medium or high.
Scope the assessment and mitigation
Negligible/low risk: a screening note plus standard mitigation usually suffices. Medium/high risk: a detailed DIA with site-specific mitigation, monitoring and a Dust Management Plan.
What Counts as a Sensitive Receptor?
The thresholds only matter if there are sensitive receptors close enough to be affected. The IAQM defines three categories.
Human Receptors (350 m buffer)
- Residential dwellings (houses, flats, HMOs)
- Schools and nurseries
- Hospitals, GP surgeries and care homes
- Hotels and student accommodation
- Public open spaces in regular use
- Allotments and community gardens
Ecological Receptors (50 m buffer)
- Sites of Special Scientific Interest (SSSIs)
- Special Areas of Conservation (SACs)
- Special Protection Areas (SPAs)
- Areas of Outstanding Natural Beauty (AONBs)
- Local Wildlife Sites and Local Nature Reserves
- Ancient woodland
Commercial / Other
- Offices and workplaces (medium sensitivity)
- Retail premises with outdoor display
- Food production / outdoor processing
- Listed buildings & conservation areas
- Existing AQMAs (Air Quality Management Areas)
- Water bodies used for recreation
Common Mistakes With the IAQM Thresholds
These are the errors we most often see in DIAs that have been sent back by planning officers for revision.
- Measuring the buffer from the activity location, not the site boundary The 350 m and 50 m buffers are measured from the red-line site boundary, not from the specific spot where dust is generated. Drawing the buffer from the demolition footprint will under-count receptors.
- Ignoring trackout because the site has a paved access road Trackout doesn't stop at the site gate. Material carried out on tyres deposits dust onto public roads for hundreds of metres, especially in dry weather. Trackout still needs assessing even with a paved access.
- Using GIA where the guidance asks for gross internal volume The demolition threshold is a volume (m³), not a floor area (m²). Multiplying floor area by storey height is the correct approach — tall industrial buildings can exceed the threshold even with a modest footprint.
- Double-counting receptors across multiple activities The same residential block doesn't become four receptors just because the site has demolition, earthworks, construction and trackout. Identify each receptor once, then assess the combined risk to it across all activities.
- Applying the older (pre-V2.2) thresholds out of habit Many DIAs prepared in 2024 still cite the >50,000 m³ demolition and >10,000 m² earthworks thresholds. LPAs are increasingly rejecting these as out of date. Always reference the V2.2 January 2024 guidance.
Frequently Asked Questions
What changed in V2.2 vs older IAQM guidance?
The January 2024 V2.2 update revised the site size thresholds above which a detailed dust impact assessment is recommended. The headline changes are: the demolition threshold rose from >50,000 m³ to >75,000 m³ gross internal volume; the earthworks threshold rose from >10,000 m² to >110,000 m². The construction floor area trigger sits at >100,000 m², and trackout is screened against >100 outward HGV movements per day (or >50 averaged over a 12-month construction period). The buffer distances for sensitive receptors remain 350 m for human receptors and 50 m for ecological receptors, measured from the site boundary.
When does my project NOT need a dust impact assessment?
If your project sits below all four V2.2 thresholds (demolition <75,000 m³, earthworks <110,000 m², construction <100,000 m², trackout <100 HGV movements/day), and there are no human receptors within 350 m or ecological receptors within 50 m of the site boundary, the IAQM guidance indicates a DIA is unlikely to be required. However, planning authorities can still attach a condition requiring a Dust Management Plan, particularly in AQMAs or where complaints history exists. Always confirm with the LPA before omitting an assessment from your planning submission.
What is the difference between a screening and a detailed DIA?
A screening assessment is a proportionate, brief evaluation that applies the V2.2 thresholds, identifies receptors, and concludes whether a detailed assessment is needed. It is suitable for many smaller sites and is often accepted by LPAs as the only assessment required. A detailed DIA is a full quantitative and qualitative assessment of all four dust-generating activities, with risk categorisation (negligible/low/medium/high), receptor sensitivity analysis and specified mitigation measures. Detailed DIAs are required when the site exceeds one or more thresholds and sensitive receptors lie within the buffer distances.
Do residential extensions need a dust impact assessment?
In almost all cases, no. Single-dwelling extensions, loft conversions and minor householder works fall well below the V2.2 thresholds and would not warrant a DIA under the IAQM guidance. The exception is where the works form part of a larger scheme (e.g. multiple plots, demolition of a substantial outbuilding, or significant earthworks for a basement). If the LPA still asks for one, a brief screening note referencing the V2.2 thresholds is usually sufficient to discharge the request.
Do I still need a CEMP if I don't need a DIA?
Possibly yes. A Construction Environmental Management Plan (CEMP) and an embedded Dust Management Plan (DMP) are often imposed by planning condition independently of whether a DIA was required at application stage. Even small sites near sensitive receptors are routinely conditioned for a DMP covering dust suppression, monitoring trigger levels and complaint procedures. This checker addresses DIA triggers only — it does not assess whether a DMP/CEMP will be required. This is a quick reference and does not replace a professional assessment.