Costing a health impact assessment where policy requires one

The cost of a health impact assessment is decided before anyone is appointed, by the scope the authority's public health team asks for. A rapid assessment is a desktop exercise working through a determinants checklist against the submitted drawings and the existing evidence base. A full assessment with primary data collection and stakeholder workshops is a different undertaking entirely, and the gap between the two is an order of magnitude. Agreeing which one applies, in writing, at pre-application stage is the only reliable way to control the budget.

There is no national statutory requirement for a health impact assessment with a planning application. The requirement comes from local policy, and in London from the London Plan's expectation that proposals assess their effects on health and health inequalities.

Which policies trigger an assessment

Start with the development plan rather than with national guidance, because this is a local requirement.

• A development plan policy requiring assessment above a stated threshold, commonly expressed in dwellings or floorspace.
• A supplementary planning document setting out the authority's preferred template and determinants.
• The local validation checklist, which may list the assessment as a submission requirement for major applications.
• In London, the London Plan's healthy city objectives, with the Mayor's guidance on how assessment should be carried out for referable schemes.
• Planning Practice Guidance on health and wellbeing, which frames health as a material consideration rather than imposing a document requirement.

Where none of those applies, a Health Impact Assessment may still be worth producing on a scheme where health objections are likely, because it puts the applicant's analysis in front of the public health consultee before the objection is written.

Rapid, intermediate and full scopes

The three scopes differ in evidence, not in topic coverage.

The cost drivers inside each scope are predictable. Whether baseline data has to be bought or is available publicly. Whether engagement is required and in what form. How many determinants the authority's matrix contains. Whether construction phase effects are assessed as well as operational ones. And whether the assessment has to be updated as the scheme changes, which on a long determination can double the fee on its own.

Determinants and the evidence behind each

A matrix based assessment works through a fixed list, and the useful discipline is to identify where the evidence already exists in the application rather than generating it again.

1. Housing quality, space standards, tenure mix and overcrowding, evidenced from the accommodation schedule.
2. Access to healthcare and other services, which overlaps directly with a Social Infrastructure Assessment.
3. Air quality, taken from the scheme's Air Quality Assessment rather than restated.
4. Noise and vibration, taken from the acoustic assessment.
5. Active travel, walking and cycling provision, taken from the transport evidence.
6. Open space, play provision and access to nature.
7. The food environment, including hot food takeaway proximity policies where they apply.
8. Employment, training and local economic opportunity.
9. Community safety and designing out crime.
10. Social cohesion, community facilities and inclusive design.
11. Climate resilience, overheating and flood risk.

Roughly two thirds of that list is already answered by documents the application contains. An assessment that cross refers to them, with a short conclusion on the health consequence, costs less and reads as more credible than one that paraphrases each technical report at length.

Stakeholder engagement and what it costs

Engagement is the main swing factor between an intermediate and a full assessment. A single scoping meeting with the public health team costs little and is almost always worth having. A programme of workshops with residents, service providers and voluntary sector organisations, properly facilitated and written up, is a substantial piece of work.

Where engagement is required, the economy is to combine it with the consultation that will happen anyway for a statement of community involvement. One set of events, designed to collect health relevant responses alongside general feedback, produces evidence for both documents.

An illustrative example

This example is illustrative. A 180 dwelling scheme on a cleared industrial site in a borough with an adopted health policy for schemes above 100 units. The validation checklist requires a health impact assessment and the public health team uses its own 12 determinant matrix.

The applicant scopes a rapid assessment at pre-application and the public health team agrees it, subject to two determinants being addressed in more depth: air quality, because the site fronts a busy road, and access to primary care, because the nearest practice list is reported to be under pressure.

The rapid assessment runs on existing evidence. The two deeper determinants need a short extension: the air quality consultant provides a residential exposure analysis for the frontage units, and the integrated care board supplies practice capacity data. The result costs a fraction of a full assessment and answers the two questions the authority actually had.

What made that work was asking which determinants mattered rather than accepting a generic template.

Mitigation and how it is secured

Recommendations that cannot be delivered are worse than no recommendations, because they give an objector a list of things the scheme does not do. Each recommendation should be matched to a mechanism.

Design changes go into the drawings and are secured by the approved plans condition. Operational commitments, such as a travel plan or an employment and training programme, are secured by condition or by a section 106 obligation. Contributions towards off site health infrastructure are obligations and have to meet the tests for planning obligations, which means a specific project and a demonstrable link to the development.

Anything that cannot be secured by one of those routes should be described as a recommendation to the applicant rather than as mitigation relied on in the assessment.

Scoping with the public health team

Four questions, asked once, will fix the cost of the document.

Which template or determinant list does the authority use, and is it published. Which scope does it expect for a scheme of this size. Which determinants does it regard as the material ones for this site. And which baseline data sources does it accept, so the assessment is not challenged on its evidence.

Put the answers in writing and attach the exchange to the assessment. An assessment that opens by stating the agreed scope and quoting the authority's own response is difficult to criticise for being too narrow.

PlanScope drafts a Health Impact Assessment with the determinant structure and policy references in place and inserts "TO BE CONFIRMED" flags wherever local baseline data has to be dropped in, which keeps the consultant time on the two or three determinants that matter. Councils expect a suitably qualified author for assessments of this kind, and professional review is strongly advised. See PlanScope pricing for the free report, the per report price and the Professional tier.

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.