Health Impact Assessment (HIA) meaning

Health Impact Assessment (HIA) is a structured, evidence-based appraisal used in planning and public decision-making to predict how a proposed policy, plan, programme or project may affect human health—positively and negatively—and to shape alternatives and mitigation before planning permission or other development consent is granted. HIA is a descriptive term rather than a single statutory procedure. However, assessment of “population and human health” is required under Environmental Impact Assessment (EIA) regimes across England and Wales, Scotland, Northern Ireland and Ireland, and under Strategic Environmental Assessment (SEA). An HIA may therefore be produced as a standalone report or integrated within an Environmental Statement or Environmental Report. Typical features include screening and scoping, use of epidemiological and socio‑economic evidence, consultation with public health bodies, identification of vulnerable groups, and recommendations to avoid, minimise or offset adverse health outcomes and to enhance benefits. Decision-makers may require an HIA via planning policy, validation requirements or planning conditions/obligations, and its adequacy can be tested at inquiry or on judicial review alongside EIA/SEA material. Usage is broadly consistent across the UK and Ireland. Wales has specific statutory powers to require HIAs for public decisions; elsewhere practice is driven by EIA/SEA duties, national planning policy and health authority guidance.