How Long Does a Fire Risk Assessment Take?

One of the most common questions Responsible Persons ask is how long a fire risk assessment takes. The short answer is that there is no fixed time set out in law. The duration depends on the size, complexity, and use of the building, as well as the level of risk present.

UK fire safety legislation focuses on whether a fire risk assessment is suitable and sufficient — not how quickly it is completed. Rushing an assessment to meet an artificial time target can result in missed hazards, non-compliance, and enforcement action.

This guide explains how long a fire risk assessment typically takes, what factors influence the duration, and what to expect from a professional assessment.

In practical terms, a fire risk assessment may take as little as a few hours for a small, low-risk premises, while larger or more complex buildings often require one or more days to assess properly, plus additional time to prepare the written report.

Is There a Legal Time Limit for a Fire Risk Assessment?

No. UK fire safety law does not specify a minimum or maximum time for carrying out a fire risk assessment.

Under the Regulatory Reform (Fire Safety) Order 2005, the legal requirement is that the assessment must be:

• Suitable and sufficient
• Carried out by a competent person
• Kept under review and acted upon

The time taken is therefore determined by what is reasonably required to assess the premises properly, not by a prescribed number of hours.

Typical Fire Risk Assessment Timescales

While there is no legal benchmark, the following timeframes reflect common industry practice for the on-site assessment element.

As a general guide:

• Small, low-risk premises (e.g. small offices, shops): Approximately 2–3 hours
• Standard commercial premises (e.g. offices, retail units, light industrial): Half a day to one full day
• Larger or more complex buildings (e.g. multi-storey buildings, residential blocks, care premises, mixed-use sites): One to several days

These times can vary significantly depending on layout, occupancy, and the complexity of fire safety systems.

These times generally relate to the on-site assessment and do not always include the preparation of the written fire risk assessment report.

What Factors Affect How Long a Fire Risk Assessment Takes?

Several factors influence the duration of a fire risk assessment, including:

Size and Layout of the Building

Larger premises with multiple floors, compartments, or complex layouts naturally take longer to assess than small, simple buildings.

Use and Occupancy

Buildings with higher fire risk or vulnerable occupants — such as care homes, HMOs, or sleeping accommodation — require a more detailed assessment.

Fire Safety Systems

The presence and complexity of systems such as:

• Fire detection and alarm systems
• Emergency lighting
• Fire doors and compartmentation
• Smoke control or suppression systems

can increase assessment time.

Level of Intrusiveness Required

Some assessments are primarily visual, while others require closer inspection of fire doors, service penetrations, or plant areas.

Documentation and Management Arrangements

Reviewing existing fire safety documentation, maintenance records, training arrangements, and emergency plans can also add to the overall time.

Does the Time Include Writing the Fire Risk Assessment Report?

Not always.

The on-site assessment and the written report are often separate stages.

For smaller premises, the report may be completed shortly after the site visit. For larger or more complex buildings, preparing a clear, detailed, and defensible report can take additional days following the inspection.

A professional fire risk assessment report should include:

• Significant findings
• Identified hazards
• Recommended remedial actions
• Priority levels and timescales
• Review information

This documentation is critical for compliance and enforcement purposes and should not be rushed.

If you are unsure how much time your premises requires, a professional assessment can help ensure the correct level of detail without unnecessary delay.

Why the Duration of a Fire Risk Assessment Matters

The time taken to carry out a fire risk assessment is not about convenience — it directly affects quality and compliance.

An assessment that is completed too quickly may:

• Miss critical fire hazards
• Fail to identify people at risk
• Overlook deficiencies in fire doors or escape routes
• Provide inadequate recommendations

Enforcing authorities assess whether fire risks have been properly identified, evaluated, and managed, rather than how quickly the assessment was completed.

Who Decides How Long a Fire Risk Assessment Should Take?

The competent person carrying out the assessment should determine the appropriate level of time and detail required based on:

• The premises
• The level of risk
• Legal expectations
• Recognised best practice

The Responsible Person remains legally responsible for ensuring the assessment is adequate, even if it is carried out by a third party.

Our Fire Risk Assessment Services

At Fire Risk Assessment Network, we carry out professional fire risk assessments that are proportionate, thorough, and legally compliant.

Our approach ensures:

• The assessment takes as long as necessary — not as little as possible
• Risks are properly identified and evaluated
• Recommendations are practical and prioritised
• Reports are clear, defensible, and suitable for enforcement scrutiny

We assess a wide range of premises, from small commercial buildings to large and complex sites.

Conclusion

There is no fixed answer to how long a fire risk assessment takes. The duration depends on the building, its use, and the level of risk involved.

What matters is not speed, but whether the assessment is suitable, sufficient, and carried out competently. Taking the right amount of time helps ensure compliance, protect occupants, and reduce the risk of enforcement action.

If you need advice on fire risk assessment timescales or require a professional assessment, contact Fire Risk Assessment Network today.