Who can prepare an air quality assessment for planning

Who can prepare an air quality assessment is not answered by any statute. There is no licence, no protected title and no legal requirement for membership of anything. What governs competence is the guidance the assessment has to follow, and whether the author can defend the method when the environmental health officer reads it. In practice that means someone who works to the Institute of Air Quality Management's guidance, holds membership of a relevant institute, and has run the kind of assessment your proposal needs.

For a commercial occupier changing use, the distinction that matters most is between a construction dust assessment and operational dispersion modelling. They require different skills and cost very different amounts.

What the professional guidance expects of the assessor

The two documents that set the method for most planning work are the Institute of Air Quality Management's guidance on assessing the impacts of construction dust, and its guidance on land-use planning and development control for air quality, produced with Environmental Protection UK.

Both are written on the assumption of a competent assessor exercising judgement. Neither prescribes qualifications. What they do is set out the steps, the screening criteria and the significance framework, so an assessment that departs from them has to explain why.

That gives a practical competence test. Ask the proposed author which guidance they will follow, which version, and where their professional judgement will be applied rather than a lookup table. An assessor who cannot answer that is not the right appointment.

Air Quality Assessment is a report type where professional input is strongly advised rather than legally required. Councils usually expect a suitably qualified author, and an Air Quality Assessment that will be scrutinised by an environmental health officer should be reviewed by someone with the relevant competence before it is submitted.

Membership and what it signals

Institute of Air Quality Management membership grades indicate assessed experience in air quality practice, and the institute publishes the guidance most assessments follow. Membership of the Institution of Environmental Sciences is common alongside it, and some assessors hold Chartered Environmentalist status awarded through the Society for the Environment.

None of those is a licence. All of them tell you the person is answerable to a code of conduct and participates in continuing professional development, which matters if the assessment is later challenged.

The same reasoning applies across the technical disciplines, and the approach to checking a contaminated land specialist's status transfers directly. Verify the individual rather than the firm, ask for the membership number, and ask who will actually write the report.

Construction dust assessment against operational modelling

These are different exercises and the appointment should say which you are buying.

A construction dust assessment follows the institute's construction dust guidance. It classifies the site by the scale of demolition, earthworks, construction and trackout, identifies receptors within set distances, assigns a risk category, and then specifies mitigation proportionate to that category. The output is a risk rating and a mitigation schedule. It needs no modelling and no monitoring, and for most changes of use inside an existing building it is all that is required.

Operational assessment is another matter. Where the proposal changes traffic flows materially, or introduces a combustion plant such as a biomass boiler or a standby generator, the assessment may need dispersion modelling. That means a modelling package, an emissions inventory, meteorological data, verification against local monitoring, and someone who has done it before.

A Ventilation and Extraction Statement is the document commercial kitchens are usually asked for, and it sits alongside rather than inside the air quality work.

Monitoring data, diffusion tubes and bias adjustment

Where an assessment relies on local monitoring, the handling of that data is the part environmental health officers examine hardest.

Automatic monitoring stations produce continuous data. Diffusion tubes produce monthly averages and are subject to bias, which is why results must be bias-adjusted using a factor from the national bias adjustment work or from a local co-location study. An assessment quoting raw diffusion tube results without adjustment is not finished.

Three further points decide whether the data supports the conclusions.

• Distance correction. A tube on a facade two metres from the kerb does not represent exposure at a receptor fifteen metres back, and correcting for that requires a stated method.
• Annualisation. Short monitoring periods must be annualised against a long-running reference site before comparison with an annual mean objective.
• Verification. Modelled concentrations must be verified against measured data at comparable locations, with the adjustment factor stated and justified.

National monitoring data and the local authority review and assessment reports are public, so a reviewer can check all of this. Assume they will.

Reviewing an assessment when environmental health objects

An objection usually names one of a small number of defects. Work through them in order.

1. Wrong guidance, or an outdated version. Check the publication the assessment cites against the current one.
2. Receptors omitted. Nearby residential windows, school playgrounds, care homes and allotments are all receptors, and a plan showing the receptor set is the quickest way to test completeness.
3. Baseline understated. Where the site is in an air quality management area, the declaration and the relevant pollutant should be stated explicitly.
4. Mitigation asserted rather than specified. "Dust suppression will be employed" is not mitigation. A schedule naming measures, trigger conditions and responsibilities is.
5. Significance conclusion unsupported. The institute's framework requires the magnitude of change to be combined with the sensitivity of the receptor, and the reasoning has to be shown.

Where the objection concerns odour rather than dust or combustion products, the assessment framework is different again and an Odour Assessment is the right document.

Mitigation the assessment has to justify

Mitigation is where assessments become conditions, so the wording you offer matters.

For construction, the output is normally a dust management plan secured by condition, with measures scaled to the risk category: wheel washing, damped cutting, sheeted stockpiles, site hoarding, and monitoring where receptors are close. A dust management plan is prepared by the contractor or the air quality consultant rather than being a PlanScope report type, so budget for it separately.

For operational impacts, mitigation runs from plant selection and stack height through to travel plan measures and electric vehicle provision. Where the authority has an emissions-based policy, expect a requirement tied to a stated standard rather than a general commitment.

Keep the mitigation proportionate to the assessed risk. An assessment that concludes low risk and then proposes extensive mitigation invites the officer to conclude that the risk assessment was wrong.

Scope of appointment for a change of use

For a shop-to-restaurant or a warehouse-to-leisure change, the scope that avoids both under and over-specification looks like this.

Ask for a written scope stating which guidance will be followed and its version, whether modelling is included or excluded, which receptors will be assessed, whether monitoring data will be used and how it will be adjusted, what deliverables are included, and who by name will author and check the report.

Ask also whether the fee includes responding to a consultation objection. That single line saves an argument, because responses to environmental health comments are frequently billed as extras.

One honest uncertainty: authorities differ considerably in whether they require any air quality assessment at all for a change of use inside an existing building with no new plant. Some ask for a short statement, others nothing, and a few apply an emissions policy to any application in an air quality management area. Ask at pre-application rather than commissioning on assumption.

Where a draft needs a named specialist's review before submission, PlanScope's professional directory is the route to a reviewer, and for specialist technical reports qualified professional input may be required.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.