Travel Distance In Fire Risk Assessments

In fire safety, travel distance is one of the key measurements recorded on a fire risk assessment — and it’s often misunderstood or misapplied. This guide explains what travel distance is, typical UK guidance figures, how to measure it correctly, and how it fits into wider fire safety thinking.

Whether you’re a fire safety professional, a responsible person, or a business owner seeking better clarity, this article will help you interpret travel distance data accurately and apply it in a compliant way.

What Is Travel Distance in Fire Safety?

Travel distance refers to the actual horizontal distance a person would walk from any point within a building to reach a safe exit or protected escape route. It’s measured along the defined escape route — not the straight-line “as the crow flies” distance — and takes account of walls, partitions, furniture, and other obstructions.

The measurement is important because longer routes increase exposure to smoke and heat in a fire and can delay evacuation. Travel distance assessments underpin decisions on escape route layout and need to be considered alongside detection, alarms, fire resistance, and management controls.

Travel distance figures are benchmark guidance, not standalone legal limits. The most commonly used benchmark distances are published in sector fire risk assessment guidance (for example, the GOV.UK guides), and are widely referenced by practitioners. They align with the travel distance approach used in Approved Document B for means of escape design, but are not a direct verbatim table from ADB.

Travel Distance Benchmarks (UK Guidance)

The table below summarises commonly referenced suggested travel distances used in UK fire risk assessment practice.

Note that published examples sometimes vary by premises type and risk profile. For example, guidance for offices and shops commonly references 18 m (single direction) and 45 m (more than one direction) in normal risk layouts, but your fire risk assessment should always apply the benchmark appropriate to the actual risk, occupancy and escape route configuration.

Key points about these figures:

• They aren’t “laws” but practical, widely used guidance from authoritative sources.
• In a fire risk assessment, if distances exceed these, you should justify why and consider control measures or layout changes.
• Risk categorisation (higher/normal/lower fire risk) is determined by building use, occupancy, detection systems, and other control measures in place.

Single vs Multiple Escape Routes

Single Escape Route

When a part of the building has only one available direction of travel to safety, such as a corridor ending in a single exit, the applicable travel distance is shorter (e.g., 12–18–25 m). This recognises the increased hazard if that one route becomes compromised.

Multiple Escape Routes

If occupants can choose between two or more directions to reach safety, the acceptable distances are longer (e.g., 25–45–60 m). Multiple routes reduce the likelihood that a fire will block all means of escape.

How to Measure Travel Distance Correctly

Accurate measurement involves more than a simple tape measure:

1. Identify all points people might be (e.g., workstations, corners, seating areas).
2. Follow the actual walking route someone would take, accounting for fixed walls, partitions, shelving or fixed furniture.
3. Measure to the nearest place of reasonable safety. In practice, this is usually a protected stair enclosure or other protected route, and then onward to a final exit where required by the building layout. This could include:
   • a protected stair enclosure (storey exit),
   • a fire compartment from which there is a final exit, or
   • a final exit itself.
4. In dead-end layouts, the initial portion of travel must comply with single-route travel distance limits, even if two alternative exit choices occur later; total travel must then be measured to the nearest storey exit or final exit.

This approach ensures you’re measuring the distance people genuinely must walk to reach safety.

Why Travel Distance Matters in an FRA

Under Article 14 of the Regulatory Reform (Fire Safety) Order 2005 (FSO), responsible persons must ensure that escape routes are maintained and lead as directly as possible to safety — including keeping them clear and safe to use.

Travel distance is one part of the means of escape evaluation in a fire risk assessment. Longer travel routes:

• increase exposure to fire, smoke, and heat,
• slow evacuation times,
• can introduce pinch points or congestion,
• and might interact with other hazards (storage, obstruction, poor lighting).

In practice, a risk assessor uses travel distance thresholds as a trigger for deeper assessment — not as a pass/fail checklist alone.

Approved Document B, Building Regulations & Risk Assessments

Approved Document B (ADB) is the main statutory guidance supporting the Building Regulations in England. It provides approaches to achieving acceptable fire safety solutions, including means of escape design. It contains the concept of travel distance as a way to ensure safe evacuation.

However:

• ADB is guidance on how to comply with Building Regulations — not itself a law.
• Fire risk assessments under the Regulatory Reform (Fire Safety) Order 2005 consider whether current measures (including travel distances) ensure safety “so far as reasonably practicable”.
• Travel distance benchmarks are therefore used as a practical reference point in FRAs but must be interpreted in the context of overall risk and controls.

This distinction is important: you may accept longer distances where compensating features (like detection or compartmentation) provide equivalent safety, but you must justify this in the assessment.

(Note: Building Regulations guidance differs across the UK; Approved Document B applies to England, with separate guidance in Wales, Scotland and Northern Ireland.)

Practical Tips for Assessors and Responsible Persons

• Consider layout changes: Blocked corridors, storage encroachment, and furniture can inadvertently increase travel distance.
• Evaluate in context: A layout that meets a travel benchmark in isolation might still be unsafe if visibility, signage, or lighting is inadequate.
• Document reasoning: If distances exceed suggested values, record why and what controls are in place to mitigate risk.
• Integrate with other safety measures: Detection systems, protected routes, and staff training all interact with travel distance effectiveness.

Conclusion

Travel distance is a fundamental metric in fire risk assessments, helping assessors and responsible persons judge whether occupants can evacuate safely. While there are widely recognised benchmark distances for different escape route configurations and risk levels, these figures are guidance rather than strict legal limits. Understanding what they mean, how to measure them properly, and how they link with other fire safety measures is key to producing accurate, defensible assessments.

If you need help reviewing your travel distances or wider escape route strategy as part of your fire risk assessment, consider engaging a competent fire safety professional.

Frequently Asked Questions

What is considered good practice when assessing travel distance?

Good practice involves:

• Measuring the actual walking route, not a straight-line distance
• Assessing travel distance from the furthest likely occupied point
• Checking for dead-end conditions before routes split
• Reviewing whether furniture, storage or partitions reduce usable width
• Considering vulnerable occupants or unfamiliar visitors
• Recording your reasoning if distances approach or exceed guidance benchmarks

Travel distance should always be assessed alongside fire detection, compartmentation, lighting, signage and management arrangements.

Are travel distance limits a legal requirement?

There is no single fixed “maximum legal distance” written in fire safety law.

Instead, UK fire safety legislation requires that escape routes are suitable, sufficient and lead as directly as possible to a place of safety.. The commonly used 12m / 18m / 25m and 25m / 45m / 60m figures are guidance benchmarks derived from statutory guidance such as Approved Document B.

If distances exceed these values, a fire risk assessment must justify why occupants can still escape safely.

How often should travel distances be reviewed?

Travel distances should be reviewed:

• When layouts change
• When new partitions or racking are installed
• When occupancy levels increase
• When building use changes
• During periodic fire risk assessment reviews

Even minor fit-out changes can create unintended dead-ends or increase walking distances.

Can detection or sprinklers allow longer travel distances?

In some circumstances, enhanced fire detection, sprinkler protection or engineered solutions (such as those designed under BS 9999) may justify extended travel distances.

These adjustments are not automatic allowances. Any increase in travel distance should be assessed by a competent person (and, where relevant, a fire engineer) using an appropriate risk-based approach (for example, BS 9999 principles), and clearly documented in the fire risk assessment.

What are the most common travel distance problems found in FRAs?

Common issues include:

• Long dead-end corridors
• Storage encroaching into escape routes
• “Alternative exits” that are too close together
• Final exits that are obstructed or locked
• Inner rooms without suitable detection

These issues often arise after building alterations rather than in the original design.

Does travel distance apply to small premises?

Yes. Even in small shops, offices or commercial units, travel distance must be considered. Smaller buildings may meet guidance naturally due to scale, but layout and risk level still matter.