What is a Category 1 hazard?

The most serious rating under the housing health and safety rating system, meaning a risk of serious harm.

Councils assess 29 hazard types including damp and mould, excess cold, fire, falls on stairs, electrical hazards and carbon monoxide. Anything scoring in the top bands is Category 1.

Where a council finds one it has a duty to act, not a discretion. That can mean an improvement notice, a prohibition order, emergency works billed to you, or prosecution.

Excess cold is the one that catches older properties, and it is closely tied to the EPC and to how the heating actually performs rather than what is installed.