Who provides the public health input to an HIA

The health impact assessment author question has a short answer and a longer one. The short answer is that nobody holds a licence to write one, so there is no statutory competence test. The longer answer is that an assessment written without public health input reads as a policy compliance exercise, and officers who have a director of public health to consult can tell the difference in a paragraph.

What planning expertise brings is the policy framework and the mechanisms for securing mitigation. What public health expertise brings is the ability to appraise evidence: to distinguish an association from an attributable effect, to know when a relative risk means very little in absolute terms, and to read local data without over-claiming.

What the assessment is expected to cover

There is no national requirement for a health impact assessment in England. The requirement comes from local policy. In London, Policy GG3 of the London Plan 2021 expects health to be assessed and several boroughs require a formal assessment for major schemes. Elsewhere it is local plan policy, a supplementary planning document, or the validation checklist that triggers it.

The content tracks the wider determinants of health rather than healthcare alone.

• Housing quality, space, overheating and fuel poverty.
• Air quality, noise and odour exposure for future occupants and existing neighbours.
• Active travel, street design and access to public transport.
• Access to and quality of open space, play space and food growing.
• The food environment, including hot food takeaway concentration near schools.
• Access to healthcare, education and community facilities, and the capacity of each.
• Social cohesion, community safety, employment and training.
• Construction phase effects, which are temporary and often the most acutely felt.

Planning Practice Guidance on health and wellbeing is the national hook, and it points to the same territory without prescribing a method.

Public health expertise against planning expertise

The division is cleaner than it sounds. A planner can identify which policies apply, what the scheme does, and how mitigation might be secured. A public health specialist can say whether the claimed health benefit is plausible at the scale proposed.

Take a worked case. A scheme proposes a pedestrian route to a station and claims a health benefit from increased physical activity. The planning contribution is the route, the desire lines and the policy support. The public health contribution is the honest caveat: route provision alone changes behaviour modestly, the effect depends on severance, lighting and perceived safety, and the assessment should not present a modelled uplift as an outcome.

That kind of restraint is what makes an assessment useful to a decision maker. The alternative, a document that finds every effect positive, gets the weight it deserves.

Health impact assessment is one of the report types where PlanScope labels professional input as recommended rather than legally required. Councils expect a suitably qualified author, and professional review is strongly advised. The meaning of competent person across planning legislation sets out where the legal requirements actually bite.

Screening, scoping and full assessment

Work in three stages, and say which stage you are at.

1. Screening. A short proportionality test: does the scheme have plausible health effects beyond those already covered by the transport, air quality and noise work? For a single infill plot the answer is usually no, and a paragraph in the planning statement is the right response.
2. Scoping. Agree with the authority which determinants are in and which are out, and what evidence each needs. Do this before data collection, and get it in writing.
3. Full assessment. Baseline, effects, mitigation, residual effects, and monitoring where relevant.

Scoping is where cost is controlled and where most disputes are avoided. An authority that has agreed to exclude the food environment for a purely residential scheme cannot reasonably ask for it at committee.

Evidence sources for local health data

Use published, citable sources and name them.

The joint strategic needs assessment prepared by the health and wellbeing board is the single most useful local document, because it states the authority's own view of its population's health priorities. The English indices of deprivation, published on gov.uk, give a ward and lower-layer output area picture. Census and mid-year population data from the Office for National Statistics supply the demographic baseline. Air quality monitoring data comes from the authority's annual status report and the national network.

Two habits separate a credible baseline from a padded one. Report the local figure alongside the national comparator so the reader can see direction and scale. And where the data is old or the geography is a poor fit for the site, say so rather than quietly using it anyway.

The director of public health as consultee

Directors of public health sit in upper-tier and unitary authorities following the Health and Social Care Act 2012. They are not listed as statutory consultees in Schedule 4 to the Development Management Procedure Order 2015, which surprises people.

The practical consequence in a two-tier area is that the district determines the application and the public health team sits in the county, so the consultation is discretionary and depends on a working relationship. Where you expect health to be contested, ask the case officer early whether public health will be consulted and offer to meet them at pre-application stage.

Integrated care boards are the other party worth approaching, because healthcare capacity contributions start with them rather than with the planning authority. A contribution request that arrives late, without an evidenced capacity gap, tends to fail the tests in regulation 122 of the Community Infrastructure Levy Regulations 2010.

Mitigation that can be secured by condition

Health mitigation only counts if it is enforceable. Split it into three categories when you write the assessment.

Conditions must meet the six tests in Planning Practice Guidance, and obligations must be necessary, directly related to the development and fairly and reasonably related in scale and kind. A health impact assessment that recommends a behaviour change programme with no delivery mechanism is recommending nothing.

Overheating is worth singling out, because it crosses from health into Building Regulations Part O and the modelling competence needed there is specific. The competence expected for dynamic overheating modelling is a separate question from health assessment competence.

Proportionate scoping for a smaller scheme

For a scheme of 20 or 30 homes, a rapid assessment is appropriate: a checklist-based review of the determinants, a short baseline drawn from the joint strategic needs assessment, and a table of design responses cross-referenced to the drawings. Ten to fifteen pages.

The failure mode at that scale is padding. A rapid assessment that reproduces national statistics for a district is worse than one that deals with three local issues properly.

Where a full assessment is needed, bring the public health input in at scoping rather than at review. A specialist asked to sign off a finished document will either rewrite it or qualify it, and both cost more than an hour of scoping input would have. PlanScope drafts the structure and the policy framework for the supporting documents, and the report index shows which carry a professional requirement. Reviewers who take on that work can be approached through the professional directory.

This is general guidance, not legal advice. Health assessment requirements vary between authorities, so 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.