Competence for a social infrastructure assessment

There is no licence or protected title for this work, so the question of who writes a social infrastructure assessment is answered by what the document has to survive. It has to survive the authority's own place planning team, the local education authority, the integrated care board and, if the application goes to appeal, an inspector reading regulation 122 of the Community Infrastructure Levy Regulations 2010. That points to a chartered planner leading, with a demographer or place planning specialist doing the yield modelling, and named service providers confirming the capacity position.

On a scheme of 200 units or more, the modelling is the part that gets picked apart. Everything else is correspondence.

What the assessment has to establish

The document answers four questions in sequence. How many people, of what ages, will the development add. Which services will they use and within what catchment. Whether those services have the capacity to absorb them. And what contribution or on-site provision closes the gap.

The last question is the one the authority cares about, and it is the one that fails if the first three are loose. A contribution request that cannot be traced back to a stated yield, a named school or practice and a stated capacity shortfall will not satisfy the tests in regulation 122, which require an obligation to be necessary to make the development acceptable, directly related to the development, and fairly and reasonably related in scale and kind.

Scope matters as much as method. This is not a health impact assessment, which looks at the determinants of health and wellbeing across a wider field. The social infrastructure work is a capacity and provision exercise covering schools, early years, primary and community health, libraries, community halls, sports and youth provision. The two documents overlap at the edges and are often asked for together.

Population and yield modelling, and who can do it

Yield modelling converts a housing schedule into people. The competence it needs is quantitative rather than regulatory: the author has to understand household representative rates, age cohort structures and the difference between a gross and a net population change on a redevelopment site.

The practical test to apply when appointing someone is whether they can explain, without notes, why a scheme of 200 flats generates a different child yield from 200 houses of the same floor area, and where the factor they are about to apply came from. Anyone who reaches straight for a single national average is the wrong appointment.

Sources for the factors themselves are usually local. Many authorities publish pupil and child yield factors in a planning obligations supplementary planning document, and those published factors should be used in preference to anything derived, with the document and its adoption date cited. Where the authority publishes none, the author derives factors from census-based household composition for the area and says so openly, showing the derivation in an appendix. Office for National Statistics subnational population projections provide the baseline trend against which the development increment sits.

Net rather than gross is a recurring error. On a site replacing 40 existing flats with 180, the assessment reports the increment and the existing population it displaces, and it says what happened to the displaced households.

Where the capacity data comes from

The capacity side is a data gathering exercise, and the competence required is knowing which published dataset is authoritative and how out of date it is.

• School places: the local education authority's own place planning or school organisation report, which sets out forecast rolls against net capacity by planning area. This is published annually by most authorities and is the document the education team will quote back at you.
• Early years: the authority's childcare sufficiency assessment, which is a statutory duty and is normally published on the council website.
• Primary health care: the integrated care board or the relevant NHS estates team for list sizes, premises capacity and any practice closed to new registrations.
• Open space, sports and play: the authority's open space and playing pitch assessments, which sit in the local plan evidence base.
• Libraries and community facilities: the authority's own service strategy, where one exists.

Use the published document, name it, and give its date. An assessment that says capacity is constrained without naming the forecast it relies on is an assertion. The same point applies in reverse: where a school has surplus places on the authority's own published forecast, say so, because arguing for a contribution against the authority's own figures is how an assessment loses credibility on every other point.

Engaging the service providers

Written engagement is the part clients try to skip and the part that carries the most weight. A short, dated letter from the education place planning officer confirming the forecast position for named schools, and a comparable response from the integrated care board, converts the whole document from modelling into evidence.

Start that correspondence early. Responses take weeks, and the education team's answer sometimes changes the scheme, for example where a site of a certain size triggers a request for a serviced primary school plot rather than a cash contribution.

Record the questions you asked, not only the answers. Where a provider does not respond, say that the request was made, give the date, and model the position from the published forecast instead. Silence recorded with a date is defensible. Silence presented as agreement is not.

Turning need into an obligation that passes the tests

The translation from shortfall to contribution needs a stated formula and a stated cost base, and the author has to be able to show that both are the authority's own where the authority has published them. Most authorities set out per-pupil or per-place cost multipliers in their obligations supplementary planning document, indexed to a construction cost index.

Set out the arithmetic in the document rather than in a covering email. One table, with the yield, the shortfall, the multiplier, the index date and the resulting figure. Then a short paragraph explaining how each element meets the three regulation 122 tests.

Where the development provides on site, the assessment specifies what is provided, who will maintain it, and the trigger for delivery. An unmaintained community building handed to a parish council without an endowment is a problem deferred rather than solved.

Where the authority does its own analysis

On larger applications the authority will run its own numbers, and the two sets will differ. That is normal and does not mean either is wrong. Differences usually come from one of three places: a different yield factor, a different catchment or planning area, or a different treatment of committed development already in the forecast.

Identify which of the three it is before arguing. Our note on what to do when a council expert disagrees with your consultant sets out the sequence that tends to resolve this without an appeal, and the short version is that the reconciliation happens at the level of the input, never at the level of the conclusion.

Gaps that get assessments sent back

The recurring weaknesses are easy to list and easy to avoid.

An assessment with no named author and no date. One national yield factor applied to every age cohort. Gross population used where net was needed. Catchments drawn as circles rather than from the authority's planning areas. No provider correspondence. A contribution figure with no index date. Education covered and early years forgotten.

Put the author's name, qualifications and the date on the front page. Our guidance on the named author and date on a planning report explains why that single line changes how an officer reads everything after it.

If you are scoping the evidence base for a major application, a Social Infrastructure Assessment draft can set out the structure and the data sources, and a Health Impact Assessment draft where the authority asks for both, with the provider correspondence and the local yield factors added by the person who gathered them. Reviewers who do this work can be found through the professional directory.

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. For specialist technical reports, qualified professional input may be required.