Health impact assessment screening and scoping matrices

The screening matrix is the shortest document in a health impact assessment and the one that determines everything after it. It tests the proposal against each determinant of health, records whether an effect is likely, and produces a reasoned decision on whether a rapid or a full assessment follows. Get it right and the scope narrows to the four or five determinants that actually matter on this site. Get it wrong and you commission a full assessment covering eleven topics, nine of which say no significant effect.

Health impact assessment is not a statutory requirement in England. It is required by development plan policy in a growing number of authorities, and that policy sets the threshold.

When a health assessment is required

Check three documents in this order: the adopted local plan, any supplementary planning document on health or on planning obligations, and the authority's local validation list. The requirement is normally expressed as a threshold, and thresholds vary.

In practice the triggers you will encounter are a residential unit count, commonly somewhere between 50 and 150 dwellings, a floorspace figure for commercial schemes, a requirement for all development referable to a strategic authority, or a site specific requirement attached to an allocation. London boroughs apply these most consistently, under the health policies in the London Plan.

Two further triggers appear less often and catch people out. Some policies require an assessment for any development in a defined area of health inequality regardless of size. Others require it where a specific use is proposed, such as a hot food takeaway near a school, or where health facilities are being lost.

Where the plan is silent, a short screening note is still worth producing on a major scheme. It costs a day, it pre-empts a request at consultation stage, and it shows a public health consultee that the question was considered. A Health Impact Assessment is one of the report types councils usually expect a suitably qualified author to prepare, and professional review is strongly advised.

Screening against the determinants of health

The determinants used in UK practice cluster into a familiar set: housing quality and design, access to healthcare services and other social infrastructure, access to open space, play space and nature, air quality, noise, light and neighbourhood amenity, accessibility, connectivity and active travel, community safety and designing out crime, access to healthy food, access to employment, training and local economy effects, social cohesion and inclusive design, use of resources, and climate resilience including overheating and flooding.

For each one the matrix needs five columns, and the fifth is the one most often left blank.

The reason column is what makes the matrix defensible. A grid of ticks and crosses with no reasoning is an assertion. A grid where each cell carries one sentence tied to a source is evidence, and a public health officer can test it.

Uncertain is a legitimate answer at screening. It usually means the determinant is scoped in for closer work, which is exactly what the screening stage is for.

Rapid against full assessment

A rapid assessment is desk based. It uses published data, the scheme's own technical reports and the development plan, and reports determinant by determinant with recommendations. On a scheme of 100 to 200 dwellings with no unusual features, that is normally proportionate.

A full assessment adds primary engagement with affected communities and local health services, a quantified baseline health profile for the catchment, more detailed analysis on the determinants scoped in, and a monitoring framework. It is appropriate for very large schemes, for schemes in areas of acute health inequality, for proposals that close or relocate a health facility, and for development introducing a substantial new source of emissions or noise close to homes.

The decision should be reasoned in the screening document rather than assumed. Where the matrix shows two or three determinants with likely negative effects and the rest neutral, say that a rapid assessment focused on those determinants is proportionate, and say why.

One honest point. Length is not quality here. A rapid assessment of 25 pages that engages with four determinants in depth is more useful to a decision maker than a 90 page document that treats all eleven at the same shallow level, and officers notice the difference.

Evidence sources that carry weight

Use published, citable sources and name them with dates. Four categories do most of the work.

National statistics for population structure, deprivation and health outcomes at small area level. The authority's own joint strategic needs assessment and annual public health reporting, which give the local priorities a consultee will expect to see reflected. The authority's air quality annual status report and any declared Air Quality Management Area. And the scheme's own technical assessments, which is where most of the real evidence sits.

That last point is worth labouring. The air quality, noise, daylight, transport, drainage and open space assessments already prepared for the application contain the quantified material the health assessment needs. The health document's job is to translate them into effects on people, not to repeat them or to generate new numbers.

What does not carry weight: unsourced assertions about wellbeing, generic literature claims with no link to the site, and statistics quoted without a year or a geography. A consultee reading an unattributed percentage will discount the whole document.

Where accessibility and inclusion are among the determinants scoped in, the evidence overlaps with the equalities work, and the approach in access and inclusion in an equalities impact assessment applies. Keep the two documents consistent, or cross refer, rather than producing two accounts of the same provision.

Framing mitigation as health outcomes

This is where most assessments fall short. Recommendations written as design instructions read as a wish list. Recommendations written as outcomes with a mechanism read as mitigation.

Compare two versions of the same point. Provide play space. Against: provide doorstep play provision within 100 metres of every dwelling, equipped for under fives, overlooked by habitable rooms, to support unsupervised outdoor activity for the age group with the lowest activity rates in the ward.

The second version tells the officer what the measure is for, how much of it there is, and how it will be secured. It can then be conditioned or included in an obligation, which is the only way a recommendation survives into the built scheme.

So for each measure, state the health determinant addressed, the quantum or specification, the mechanism, which drawing or document shows it, and whether it is already committed or newly offered. A table with those five columns is what the committee report will lift from.

Avoid recommending things outside the applicant's control. A recommendation that the authority improve a bus service is not mitigation for your development, and including it weakens the document. The exception is where a contribution is being offered to deliver it, in which case say so.

Presenting the matrix so it can be checked

Put the full screening matrix in the body of the report rather than in an appendix, because it is the part a reader needs first. Keep it to one landscape page per determinant group if it will not fit on a single page.

Then add three things. A short statement of methodology naming the framework used and the date of each data source. A statement of who prepared the assessment and their relevant experience. And a residual effects table showing, for each determinant scoped in, the effect before mitigation, the measure, the securing mechanism and the residual effect.

Cross reference to the technical reports by document title and revision, not by subject. A health assessment citing the noise report generally, when three revisions exist, is unverifiable.

For context on how the individual determinants are then worked through in the body of the report, see health determinants inside a health impact assessment, and the full set of document types sits at all 66 report types.

PlanScope drafts a health impact assessment structured to UK planning policy and marks where local health data is still needed. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. 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.