4 Types of Fire Risk Assessment Explained

A fire risk assessment for a block of flats is not always limited to corridors, stairwells and shared entrances. The 4 types of fire risk assessment describe how far an assessment needs to extend, including whether it considers the inside of individual flats and whether invasive inspection is required. Selecting the right type helps responsible persons protect residents, identify hidden weaknesses and demonstrate that fire safety duties are being managed properly.

These categories are particularly relevant to purpose-built blocks of flats, converted houses and other residential buildings with common parts. They are not a substitute for a careful, building-specific assessment. The right scope depends on the construction, age, alteration history and known fire safety concerns within the premises.

Why the assessment type matters

A fire risk assessment should identify fire hazards, people at risk and the measures needed to prevent fire and support safe escape. In residential blocks, that often includes assessing ignition risks in communal areas, emergency lighting, fire alarm arrangements, fire doors, escape routes and the building’s compartmentation.

However, a visual inspection of common parts cannot always confirm whether fire separation between flats, service risers and escape routes is effective. Poorly sealed service penetrations, unrecorded building works or defective flat entrance doors may only become apparent through a more detailed inspection. This is where the four assessment types provide a useful framework.

The types move from a non-destructive inspection of common areas to more intrusive work covering both common parts and individual flats. More intrusive work can reveal more, but it also causes greater disruption and may require access arrangements, opening-up works and subsequent repairs. A proportionate approach is essential.

The 4 types of fire risk assessment

Type 1: Common parts, non-destructive

A Type 1 assessment is the most common starting point for a purpose-built block of flats. It is a non-destructive inspection of the common parts of the building, such as entrance halls, corridors, staircases, shared plant rooms and external escape routes.

The assessor reviews visible fire safety measures and considers whether the building’s fire strategy appears suitable. They may inspect the condition of communal fire doors, emergency lighting, signage, refuse storage, electrical cupboards and visible compartmentation. They will also look for obvious defects, including unprotected openings around pipes or cables passing through walls and floors.

No walls, ceilings or floors are opened during a Type 1 assessment. Nor does it normally involve entering residents’ flats, except where access is agreed and clearly relevant to a visible concern.

This type is often appropriate where there is no reason to suspect significant hidden defects and the building has a straightforward history. It does not prove that every concealed element of compartmentation is sound. Where warning signs exist, a more detailed survey may be necessary.

Type 2: Common parts, destructive

A Type 2 assessment covers the same common parts as Type 1 but includes destructive or intrusive inspection where needed. This may involve lifting ceiling tiles, opening access panels, inspecting boxed-in services or carefully opening limited areas of construction to check fire stopping and compartmentation.

This approach is useful when a Type 1 inspection has identified concerns that cannot be resolved visually. For example, visible gaps around service risers, evidence of poorly controlled refurbishment work or uncertainty about the construction of walls protecting an escape route may justify targeted opening-up.

A Type 2 assessment should be planned carefully. The scope must be proportionate, with agreement on who will undertake opening-up and making-good works. It may also be sensible to coordinate the work with a fire compartmentation survey, particularly in older buildings or properties that have undergone repeated alteration.

While the inconvenience is greater than with Type 1, a targeted intrusive inspection can prevent serious issues from remaining concealed. It can provide the evidence needed to prioritise repairs with confidence.

Type 3: Common parts and flats, non-destructive

A Type 3 assessment extends beyond the common parts and considers individual flats on a non-destructive basis. It examines how risks within flats could affect residents, neighbours or the building’s escape routes.

This may include checking flat entrance doors, considering the likelihood of fire starting within a dwelling and reviewing whether the separation between flats appears adequate. The assessor may also consider escape windows, internal layouts and visible fire hazards where access is available.

Type 3 is more appropriate where there are concerns that cannot be understood by assessing common areas alone. Converted properties can be a particular example, especially where the standard of conversion, changes to layouts or the condition of separating construction is uncertain. It may also be relevant where residents are particularly vulnerable or where a building’s evacuation arrangements require closer scrutiny.

Access to flats needs sensitive planning and clear communication. Residents should understand why the inspection is taking place and what areas will be considered. The assessment remains non-destructive, so it cannot confirm concealed defects inside walls, floors or ceilings.

Type 4: Common parts and flats, destructive

A Type 4 assessment is the most extensive of the four types. It includes both common parts and individual flats, with intrusive inspection where required to investigate hidden aspects of construction and fire separation.

It is generally reserved for buildings where there are substantial concerns about compartmentation or fire safety arrangements. These might include major refurbishment, a history of uncontrolled alterations, evidence of structural or fire-stopping defects, or serious uncertainty about how the building was constructed.

The process can involve opening selected sections of walls, ceilings, floors, service enclosures or other construction elements. It should therefore be carefully scoped, managed and documented. Residents, owners and contractors need to understand the access requirements, possible disturbance and responsibility for reinstatement.

A Type 4 assessment is not automatically the best or safest choice simply because it is the most detailed. Unnecessary destructive work can be costly and disruptive. Equally, relying on a Type 1 inspection when evidence points to concealed defects can leave a serious risk unresolved. The decision should be based on professional judgement and the evidence available.

Which fire risk assessment type does your building need?

For many well-managed blocks of flats, a Type 1 assessment will be suitable as the initial assessment and for routine review. It provides a practical view of the shared areas and highlights visible defects that need attention.

A more extensive type may be justified where the building is older, has been converted, has undergone significant refurbishment, or presents visible signs of defective compartmentation. Repeated breaches through fire-resisting walls, uncertainty around service risers, damaged flat entrance doors and unclear construction records all deserve closer attention.

The assessment type should also reflect the building’s fire strategy. A stay-put policy depends heavily on effective compartmentation between flats and protected common areas. If there is reason to question those measures, a basic visual inspection may not provide sufficient reassurance. Buildings with simultaneous evacuation arrangements may have different priorities, including alarm coverage, management procedures and escape capacity.

What responsible persons should do next

The responsible person should ensure that the assessment is suitable and sufficient for the premises, recorded where required, and kept under review. Fire risk assessments are not static paperwork. They should be revisited after significant building alterations, changes in occupancy, a fire incident, enforcement action or the discovery of material defects.

Clear actions matter as much as a thorough inspection. Recommendations should explain the issue, its priority and the practical remedial work needed. This may include repairing or replacing fire doors, improving emergency lighting, removing ignition sources from escape routes, installing appropriate signage or commissioning a specialist compartmentation survey.

For property owners and managers across Kent, East Sussex and West Sussex, Kent and Sussex FRA provides comprehensive assessments and practical guidance to help turn findings into achievable safety actions. A professionally scoped assessment can provide a defensible starting point, whether your building needs a routine Type 1 review or further investigation.

The right assessment is the one that gives you a clear, evidence-based view of your building’s risks and a realistic plan to protect the people who rely on it every day.