Social Infrastructure Assessment or Health Impact Assessment

Whether you need a social infrastructure or health impact assessment depends on what the council is actually asking you to answer. One counts places: school rolls, GP list sizes, pitch capacity, library floorspace. The other looks at how the scheme affects the things that make people healthy or unhealthy, from active travel and air quality to housing quality and access to green space.

They get confused because both appear in the same policy sections and both end up feeding the section 106 discussion. The distinction is worth holding, because a health impact assessment cannot support a contribution to a primary school and a social infrastructure assessment will not answer a policy asking about health inequalities.

What each assessment establishes

A Social Infrastructure Assessment quantifies the additional demand the development places on community facilities and compares it against existing capacity. Population yield from the housing mix, then pupil yield by phase, then primary care list growth, then demand for open space, sports provision and community meeting space. The output is a table of surpluses and deficits, with a case for what is needed to address them.

A Health Impact Assessment appraises the effect of the scheme on the determinants of health for both future occupants and the existing population. Housing quality and overcrowding, walkability and cycle access, air quality, noise, daylight, access to green space, the food environment, employment and training, and community cohesion.

The first is arithmetic followed by negotiation. The second is appraisal followed by design change. That difference shapes when each should be commissioned.

Facility capacity against health outcomes

The health assessment has a habit of producing recommendations that cost nothing and change a lot: moving a pedestrian route, widening a stair, putting play space where it is overlooked, removing a blank frontage. The infrastructure assessment produces numbers that cost a great deal and change little about the building.

Data sources for each

Social infrastructure work runs on published local data. School place planning reports from the local education authority, pupil yield factors from the council's own planning obligations guidance, GP list sizes and premises capacity held by the integrated care board, playing pitch strategies and open space assessments prepared for the local plan, and the council's infrastructure delivery plan.

Use the council's own yield factors where they exist. An applicant who imports generic yields and produces a lower pupil number than the council's adopted figures has started an argument they will lose, and the officer will simply substitute the adopted rates.

Health impact work draws on a different set: the local joint strategic needs assessment, public health profiles for the area, indices of deprivation, air quality monitoring data, and the scheme's own technical reports. The air quality chapter, the noise chapter and the daylight work are inputs to the health appraisal rather than separate exercises, which is why an assessment written before those reports exist tends to be thin.

Both should name their sources and dates. Vague references to local health data with no citation is the most common weakness in submitted health assessments.

Contributions and how they are justified

Contributions from a social infrastructure assessment have to pass the statutory tests in regulation 122 of the Community Infrastructure Levy Regulations 2010: necessary to make the development acceptable in planning terms, directly related to the development, and fairly and reasonably related in scale and kind.

That test does real work. A contribution towards a school with surplus places in the relevant planning area fails the first limb. A contribution calculated across an authority-wide formula, with no link to the catchment serving the site, is vulnerable on the second. The restriction on pooling more than five obligations towards a single item was lifted in 2019, so pooling itself is no longer the obstacle it once was, but the three tests remain.

Health impact assessments rarely generate contributions directly. Their recommendations land as design changes, as conditions, or occasionally as a travel plan measure or a local employment obligation. Presenting a health assessment as a contribution justification usually fails, because the causal chain between a payment and a health outcome is too long for regulation 122.

Where viability is tight, the infrastructure package becomes the negotiation. Our note on viability at plan making or at application stage sets out which of those two moments the argument belongs in.

Consultee input from service providers

Neither assessment should be written in isolation from the bodies that run the services.

Write to the education authority, the integrated care board and the council's open space team early, state the housing mix and the anticipated completion programme, and ask for their capacity position in writing. What comes back is the evidence base the officer will use anyway, and getting it early means the assessment addresses it rather than contradicting it.

Health assessments gain from contact with the council's public health team, which in unitary and county authorities sits outside planning and is often consulted on major applications. A short conversation at pre-application stage will tell you whether the council expects a rapid screening appraisal or a full assessment, and that distinction is worth several thousand pounds of fee.

Where both are requested

Large residential-led schemes in London and in authorities with health-focused local plan policies regularly attract both. When that happens, sequence them rather than running them in parallel.

The social infrastructure work should come first, because its population yield and demand figures feed straight into the health appraisal's assessment of access to services. Running them together produces two documents with different population assumptions, which an officer will notice.

Keep the open space analysis in one place. Where the scheme needs an Open Space Assessment as well, both the infrastructure and health documents should reference it rather than restating it with slightly different numbers. The same applies to any Equalities Impact Assessment, which overlaps with health on accessibility and on effects falling unevenly across population groups.

Proportionate scope

Scale both to the scheme. A 25-unit scheme does not need a full health impact appraisal with a monitoring framework, and a council asking for one should be asked which policy requires it and at what threshold.

A reasonable rule of thumb, and it is only that: social infrastructure analysis becomes worthwhile at the point where the scheme generates enough population to register against a facility's capacity, which in most authorities means somewhere above 50 dwellings. Health appraisal thresholds are usually set explicitly in local policy, often at major development or at a stated unit count.

Ask for the threshold in writing at pre-application stage, and ask which specific policy it comes from. Requests that cannot name a policy are usually negotiable.

PlanScope can draft either document to the structure councils expect, with the policy basis cited and every figure marked as still to be confirmed until local data is supplied. 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.