What is the maximum travel distance in a dwelling?

In a dwelling (house), the maximum travel distance to a final exit or protected stairway is 9 metres in a single direction of escape. This is measured along the actual route of travel, not as a straight line. For houses of three or more storeys, additional provisions may be needed such as a protected stairway.

What fire doors do I need in a 3-storey house?

In a dwelling of 3 or more storeys, FD30 (30-minute) fire doors with self-closing devices are required to all habitable rooms that open onto the escape route (hallway, landing and stairway). This includes bedrooms, living rooms, and kitchens. The stairway should be enclosed as a protected route from top to bottom.

What fire door rating is needed for a flat entrance door?

Flat entrance doors must be FD30S — a 30-minute fire door with smoke seals (the S suffix indicates cold smoke seals). This applies to all flats regardless of the number of storeys. The door must also be fitted with a self-closing device to ensure it shuts automatically.

How wide does an escape corridor need to be?

The minimum corridor width depends on the number of people using it: fewer than 50 people requires 1050 mm minimum, 50-110 people needs 1200 mm, 111-220 people needs 1500 mm, and over 220 people needs 1800 mm. For dwellings, the practical minimum is usually 900 mm but 1050 mm is recommended for escape routes.

What is an HMO and what fire safety rules apply?

An HMO (House in Multiple Occupation) is a property rented to 3 or more people forming 2 or more households who share facilities. HMOs have stricter fire safety requirements including FD30S fire doors to all bedrooms and kitchens, a Grade D LD2 fire alarm system (interlinked smoke and heat alarms), emergency lighting in common areas, and fire safety signs. LACORS Housing Fire Safety guidance provides detailed requirements.

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Fire Escape Route Calculator — Check Compliance with Approved Document B

Check whether your escape route distances, corridor widths, and number of exits comply with UK fire safety regulations. For dwellings, flats and HMOs.

Building Type

Select the type of residential building

Number of Storeys

Total number of floors in the building

Occupants Per Floor

Maximum number of people on each floor

Maximum Travel Distance to Exit

Longest distance from any room to the nearest exit

Corridor Width

Width of the escape corridor / hallway

How We Calculate This

This calculator checks your escape route design against the requirements of Approved Document B (Fire Safety) and BS 9991 for residential buildings. It covers travel distances, corridor widths, number of exits, and fire door requirements.

Maximum Travel Distances

Dwelling: 9 m single direction
Flat (within flat): 9 m to entrance door; 7.5 m dead-end corridor, 30 m with alternatives
HMO: 9 m single direction, 18 m with alternative directions

Corridor Width Requirements

<50 people: 1050 mm
50-110 people: 1200 mm
111-220 people: 1500 mm
220+ people: 1800 mm

References

Approved Document B — Fire Safety (Volume 1: Dwellings, Volume 2: Non-dwellings)
BS 9991:2015 — Fire safety in residential buildings
LACORS Housing — Fire Safety (guidance for HMOs)

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Verify with your supplier.