A Type 1 fire risk assessment is non-destructive and covers the common parts of a building only. A Type 4 assessment is destructive and covers both the common parts and a sample of the individual flats, opening up construction to inspect compartmentation. Type 1 is the usual baseline; Type 4 is commissioned when there is real doubt about the structure.
The four types at a glance
The commonly used typology comes from LGA and industry guidance sitting alongside PAS 79. It varies along two axes: whether the assessment covers only common parts or also the dwellings, and whether the inspection is non-destructive or destructive.
- Type 1: common parts only, non-destructive. The standard baseline assessment.
- Type 2: common parts only, destructive. Used where compartmentation in common areas is in doubt.
- Type 3: common parts and flats, non-destructive. Considers risk to occupants inside dwellings.
- Type 4: common parts and flats, destructive. The most thorough and the most disruptive.
When Type 1 is the right call
For most purpose-built blocks and converted properties with documented construction and no history of unexplained fire spread or alteration, a Type 1 assessment satisfies the duty under the Regulatory Reform (Fire Safety) Order 2005 to assess the risk in the common parts. It examines escape routes, fire doors, signage, emergency lighting, alarm provision, housekeeping and management arrangements without opening up the fabric of the building.
It is quicker, cheaper and non-disruptive, and it is the assessment type most landlords and managing agents should be renewing on a regular cycle.
When Type 4 becomes necessary
A Type 4 is justified when the Type 1 raises questions the assessor cannot answer from the surface: undocumented conversions, suspected missing compartmentation between flats, unknown work by previous owners, or a building where a fire has already spread further than the design should have allowed. Because it involves opening up construction and inspecting inside a sample of dwellings, it needs tenant access, making good afterwards, and a clear scope agreed in advance.
It is not a routine renewal. Commissioning a Type 4 where a Type 1 would do adds cost and disruption without improving safety.
How often should an assessment be reviewed?
The Fire Safety Order requires the assessment to be kept up to date rather than repeated on a fixed calendar, but the practical convention is an annual review with a full reassessment every one to three years depending on risk, and immediately after any material change: a conversion, a change of use, a new tenant group, alterations to escape routes or a fire.
Frequently asked questions
- Is a fire risk assessment a legal requirement?
- Yes. The Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to carry out and keep up to date a fire risk assessment for non-domestic premises and the common parts of residential buildings, and to record the significant findings.
- Does a Type 1 assessment cover inside the flats?
- No. A Type 1 assessment is limited to the common parts. If risk inside the individual dwellings needs to be considered, a Type 3 or Type 4 assessment is required.
- Who can carry out a fire risk assessment?
- A competent person with sufficient training, experience and knowledge of the building type. For simple premises the responsible person may do it themselves; for HMOs, blocks of flats and commercial premises an experienced assessor working to PAS 79 is the practical standard.