Purpose-built blocks of flats

Types 1, 2, 3 and 4 fire risk assessments

Types 1–4 describe how far an assessment of a purpose-built block of flats extends into construction and individual flats. They are not universal grades for every property.

Reviewed: 22 July 2026Guidance: EnglandReading time: approximately 8 minutes

Start here

Types 1–4 are residential assessment scopes—not quality levels

The terminology comes from government-endorsed guidance for purpose-built blocks of flats. It describes the extent of inspection: common parts or flats, and non-destructive or destructive. It does not mean Type 4 is automatically “better” or that a shop, office or care home needs one of these four labels.

The correct type must be proportionate to the building and evidence. A competent assessor should explain why a more intrusive or extensive scope is justified.

Common parts · non-destructive

Type 1 fire risk assessment

Type 1 is the basic assessment used to satisfy the Fire Safety Order for most purpose-built blocks. It examines common parts, escape arrangements and relevant fire precautions without opening up construction.

It should include examination of at least a sample of flat entrance doors and consider, so far as reasonably practicable, construction separating flats from common parts. Readily accessible risers or demountable ceiling tiles may be opened without this becoming destructive inspection.

  • Common parts and relevant building elements
  • Non-destructive visual inspection
  • Sample of flat entrance doors
  • No entry beyond the flat entrance-door area as part of normal scope
  • Can recommend targeted investigation where evidence creates genuine doubt

Common parts · destructive

Type 2 fire risk assessment

Type 2 has broadly the same objectives as Type 1 but adds destructive inspection on a sampling basis to examine hidden construction and compartmentation. A contractor is normally needed to open up and make good.

It is usually a one-off investigation where there is good reason to suspect serious structural fire-protection deficiencies. Age alone is not normally sufficient justification. Sampling may sometimes include construction within vacant flats where needed to understand separation.

  • Common-parts assessment plus sampled opening-up
  • Targets suspected hidden structural or fire-stopping deficiencies
  • Requires an opening-up and reinstatement plan
  • May require asbestos information and other safety controls
  • Should be evidence-led rather than routinely specified

Common parts and flats · non-destructive

Type 3 fire risk assessment

Type 3 includes Type 1 work and extends non-destructive inspection into at least a sample of flats. It considers means of escape within flats, smoke alarms and the fire resistance of internal doors.

This scope goes beyond the Fire Safety Order’s normal reach inside domestic premises, though housing legislation may be relevant. It can be appropriate where there is reason to suspect serious risk within flats, particularly in rented stock where lawful access can be arranged.

  • Type 1 common-parts scope
  • Non-destructive inspection within sampled flats
  • Internal escape, detection and relevant internal doors
  • Access rights, resident communication and representative sampling
  • Not automatically feasible in long-leasehold flats

Common parts and flats · destructive

Type 4 fire risk assessment

Type 4 has the broad scope of Type 3 and adds destructive sampling in both common parts and flats. It is the most extensive of the four types and normally requires contractors, resident coordination, reinstatement and careful health-and-safety planning.

Official guidance reserves it for limited circumstances, such as unknown work history combined with reason to suspect serious risks to residents from fire within their own or neighbouring flats. Destructive work in flats is often practicable only when they are vacant.

  • Type 3 scope plus sampled opening-up
  • Intrusive inspection in common parts and selected flats
  • Evidence-based locations and methodology
  • Asbestos-register and other pre-construction checks
  • Access, decanting, security, making-good and evidence records

Commissioning decision

How should the assessment type be chosen?

Start with building information, previous assessments, alterations, incidents and known defects. The assessor should identify the question the inspection needs to answer and explain why the selected type and sample can answer it.

Do not confuse Types 1–4 with external-wall appraisal, a fire-door inspection, a compartmentation survey or a fire strategy. These may interact with the FRA but have different scopes and competencies.

01

Use Type 1

The routine starting point for most purpose-built blocks where there is no specific evidence of serious hidden deficiency.

02

Escalate investigation

When evidence, alterations, incidents or uncertainty create a reasoned concern that visual assessment cannot resolve.

03

Add flat sampling

When internal escape or detection needs assessment and lawful, representative access can be arranged.

04

Define specialist work

Commission external-wall, door, compartmentation or engineering work expressly rather than assuming a type number includes it.

Before appointment

Questions to put in the quotation request

The brief should name the intended assessment type and describe access, sampling, destructive work and reinstatement. Ask the provider to challenge the proposed type if their review of the evidence suggests a different scope.

Check competence for residential buildings and the proposed intrusive work. Consider BAFE SP205 for organisation-level FRA certification and NFRAR for individual assessor registration, together with direct experience of comparable blocks.

  • Why is this assessment type necessary?
  • Which common areas, flats and building elements are included?
  • How many flats or locations will be sampled and why?
  • Who arranges resident access, opening-up and making good?
  • What asbestos and safe-working information is required?
  • Which specialist surveys are included or excluded?
  • Who will assess, validate and answer post-report questions?

Apply the guidance

Connect the requirement to your premises

Use a property-specific guide for the risks and management questions relevant to your building, or explore the local London and Surrey assessment pages.

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Frequently asked questions

Types 1, 2, 3 and 4 fire risk assessments FAQs

Is a Type 4 FRA always better than Type 1?

No. The type describes scope, not quality. Type 4 is more intrusive and extensive but is justified only in limited circumstances. Type 1 normally suffices for most purpose-built blocks.

Which FRA type is needed for a block of flats?

Type 1 is the normal starting point for most purpose-built blocks. Building evidence, suspected defects, access and the purpose of assessment may justify another type. A competent assessor should explain the decision.

Does a Type 1 FRA inspect flat entrance doors?

Yes. Official guidance says at least a sample of flat entrance doors should be examined, although normal Type 1 scope does not extend inside flats beyond the entrance-door area.

Are Types 2 and 4 destructive?

Yes. Both involve destructive inspection on a sampling basis. Type 2 is principally common-parts scope; Type 4 also extends into sampled flats.

Do Types 1–4 apply to HMOs, offices or shops?

The classification was developed for purpose-built blocks of flats. Other premises need a suitable and sufficient scope based on their own law, use and risks, rather than automatically applying these type numbers.

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Sources and limitations

Guidance reviewed 22 July 2026

This page provides general information for England. It is not legal advice or a building-specific assessment. Fire Safety Services is independent and is not affiliated with the Government, enforcing authorities, BAFE, NFRAR or IFSM.

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