What is a category 1 hazard under HHSRS?
The Housing Health and Safety Rating System scores 29 hazards. A category 1 hazard is a serious risk to health or safety, and where one exists the council has a legal duty to act — usually with an improvement notice, and in serious cases a prohibition order.
3 min read · Updated 2 August 2026
Overview
The Housing Health and Safety Rating System scores 29 hazards. A category 1 hazard is a serious risk to health or safety, and where one exists the council has a legal duty to act — usually with an improvement notice, and in serious cases a prohibition order.
Practical guidance
- Treat damp and mould, excess cold, fire and fall hazards as the highest-risk headings.
- Respond to a council inspection request quickly and in writing.
- Fix and evidence the remedy before the notice deadline to avoid a civil penalty.
Related content
General information for UK landlords and letting agents, not legal advice. Rules differ across England, Wales, Scotland and Northern Ireland — check your local requirements or take advice before acting.