Fire risk assessments for London HMOs, blocks of flats, and commercial premises

The Regulatory Reform (Fire Safety) Order 2005 — universally abbreviated to the RRO 2005 — is the primary fire safety legislation covering England and Wales. It consolidates more than 70 earlier Acts and Regulations into a single, outcomes-based framework that places a clear legal duty on the responsible person to manage fire risk in any premises to which it applies.

The RRO 2005 applies to all non-domestic premises and to the common parts of residential buildings where those parts are not private living areas. This means it covers the hallways, stairwells, communal kitchens, bin stores, roof spaces, and any other area shared between occupants of an HMO or block of flats. It does not apply to private, single-family occupied dwellings, but it applies the moment two or more households share any common area.

The responsible person is defined as the employer, where premises are a workplace; the person in control of the premises, where premises are not a workplace; or the owner, where no person is in control. For an HMO landlord, this is unambiguously the landlord. For a block of flats managed through a managing agent, the freeholder retains ultimate responsibility even where day-to-day management is delegated.

The RRO 2005 does not prescribe a specific method or format for the assessment. It requires that it be "suitable and sufficient" and that it be reviewed when there is reason to believe it is no longer valid. In practice, London borough housing authorities and the London Fire Brigade expect written assessments produced to PAS 79:2020 standard by a competent assessor — and in the context of HMO licensing, that means an NFRAR-registered assessor at Tier 3.

Enforcement of the RRO 2005 in London sits primarily with London Fire Brigade and, for residential premises covered by housing legislation, with the 33 London borough housing authorities. Both bodies have statutory powers to inspect premises, require evidence of a fire risk assessment, and take enforcement action where fire safety precautions are inadequate.

London Fire Brigade can serve Enforcement Notices requiring specific remedial works within a stated period, Prohibition Notices restricting or prohibiting use of all or part of a building, and — in the most serious cases — prosecute the responsible person in the criminal courts. Prosecution under the RRO 2005 carries unlimited fines and, for the most serious failures, imprisonment. There is no upper limit on the fine a Magistrates' Court can impose.

For HMOs, the local authority housing team has overlapping powers under the Housing Act 2004 and its associated licensing regime. An HMO operating without a valid fire risk assessment, or with fire safety defects that have not been addressed following an assessment, can have its licence refused or revoked — rendering continued letting a criminal offence carrying a fine of up to £30,000 per offence.

The Building Safety Act 2022 has further strengthened obligations for higher-risk residential buildings — those above 18 metres or 7 storeys. Responsible persons for these buildings are subject to enhanced duties, mandatory registration with the Building Safety Regulator, and annual safety case reviews. Our assessors are familiar with the Building Safety Act framework and can advise on obligations for taller blocks.

Compartmentation is the passive fire protection strategy that contains fire and smoke within a defined zone of a building for long enough to allow evacuation and fire brigade intervention. In a purpose-built block of flats, each flat is a compartment, constructed with fire-resistant floors, walls, and ceiling to contain any fire that breaks out within the flat for a defined period — typically 60 minutes.

London's HMO stock is dominated by Victorian and Edwardian terrace conversions that were never designed as compartmented buildings. The original floor and wall construction may provide some inherent fire resistance from solid brickwork and timber-floored construction, but the service installations added during conversion — gas pipes, electrical conduit, waste stacks, central heating pipework — routinely breach the floor slab and party walls, creating unprotected pathways for fire and smoke to travel between floors and between flats.

A fire that begins in the ground-floor kitchen of a Victorian terrace conversion can travel to the upper floor via the floor void beneath the first-floor boards in a matter of minutes if service penetrations are unsealed. This is not a theoretical risk — it is the mechanism by which a disproportionate number of fatal HMO fires have killed occupants on upper floors who were unaware a fire had started below them.

A compartmentation inspection as part of a fire risk assessment is not a destructive survey — we do not open up floors or walls. It is a visual and tactile inspection of accessible void edges, ceiling junctions, and service entry points that can be inspected without opening the building fabric.

Where access is possible — through loft hatches, understairs cupboards, service riser doors, or exposed ceiling voids — we inspect for:

• Pipe penetrations through floor slabs without intumescent collars or fire-rated sealant
• Cable and conduit penetrations through fire compartment walls without mineral wool packing and intumescent sealant
• Gaps at the junction of partition walls and the original floor slab where conversions have added stud walls
• Loft hatches without fire-rated linings in converted attic rooms
• Party wall breaches in terraced properties where service installations have been run through shared walls
• Damaged plasterboard ceilings in converted basements that allow direct access to the floor void above

PAS 79:2020 is the publicly available specification published by BSI that defines best practice for the preparation and presentation of fire risk assessments. It does not replace the RRO 2005 legal requirement for a "suitable and sufficient" assessment, but it defines what a professional, defensible assessment should contain: premises details and occupancy data, photographs of significant findings, a systematic record of hazards identified, risk ratings, existing precautions noted, and a prioritised action plan with clearly assigned responsibilities.

All 33 London borough housing authorities have adopted PAS 79 as the expected format for fire risk assessments submitted in support of HMO licence applications. An assessment that does not follow the PAS 79 structure — produced by an unregistered assessor or presented as a simple checklist without risk evaluation — is frequently rejected by housing officers and requires a new assessment before the licence can progress.

Our assessors produce reports that include a photographic schedule of all significant findings, risk ratings on the likelihood × consequence matrix, and recommendations clearly categorised as immediate, one month, three months, or twelve months. The report is signed by the responsible assessor and includes their qualifications and NFRAR registration number.

The National Fire Risk Assessors Register (NFRAR) operates a tiered registration system based on the complexity of premises the assessor is qualified to assess. Tier 3 covers blocks of flats, HMOs, sheltered housing, and residential care premises — the categories most relevant to London landlords. All 33 London boroughs confirm acceptance of NFRAR Tier 3 registered assessors for HMO licensing purposes. Our assessors hold current NFRAR Tier 3 registration.

The RRO 2005 requires review of the assessment whenever circumstances change, but does not specify a fixed review interval. For HMOs, the accepted standard — and the requirement under most London borough HMO licensing conditions — is annual review. In practice, this means either a new site inspection and updated report, or a documented desk review confirming the existing assessment remains valid and that no material changes to the premises or occupancy have occurred.

Higher-risk premises — HMOs with six or more occupants, blocks with more than four storeys, premises with a history of fire-related incidents — should be reviewed more frequently or following any structural alteration, change in use, significant refurbishment, or fire alarm activation.