What lux level is required for emergency lighting?

BS 5266-1 specifies different lux levels for different areas. Escape routes require minimum 1 lux measured along the centre line of the route, excluding a 0.5m border strip. Open areas over 60 square metres need 0.5 lux horizontal at floor level for anti-panic lighting. High risk task areas need 10 percent of normal maintained illuminance or 15 lux minimum. These are minimum levels measured at floor level and apply when normal lighting has failed.

How long must emergency lighting batteries last?

BS 5266-1 requires a minimum battery duration of 1 hour for premises that can be evacuated immediately and are not used for sleeping. Sleeping premises (hotels, care homes, residential), entertainment venues, and complex buildings require 3 hours minimum battery duration. Most commercial installations default to 3 hours to provide a safety margin and cover the range of building uses. Self-contained LED emergency luminaires typically achieve 3 hours with a NiMH or LiFePO4 battery pack.

Where must emergency luminaires be positioned?

BS 5266-1 requires emergency luminaires at specific locations: near each exit door, at changes of direction in escape routes, at corridor intersections, outside each final exit, near stairs so each flight receives direct light, near fire alarm call points, within 2 metres of fire safety equipment (extinguishers, first aid points, fire alarm panel), in toilets and changing rooms over 8 square metres, in lift cars, and near safety signs. Exit signs must be illuminated at all exit points.

How often must emergency lights be tested?

BS 5266-1 Section 12 requires routine testing: monthly functional tests (brief flick test to verify operation), six-monthly tests (one-quarter of rated duration), and annual full-duration discharge tests (1 or 3 hours depending on the system). All test results must be recorded in an emergency lighting log book. Automatic test systems using DALI or self-test luminaires can reduce the manual testing burden, but annual verification inspections are still required.

What is the difference between maintained and non-maintained emergency lighting?

Maintained emergency luminaires are on all the time (acting as normal lighting and switching to battery power on mains failure). Non-maintained luminaires only switch on when the mains supply fails. Maintained mode is required in entertainment venues, theatres, cinemas and areas where normal lighting may be dimmed. Non-maintained is suitable for most offices, shops and escape routes where normal lighting is always on during occupation. BS 5266-1 clauses 5.1 and 5.2 provide guidance on the appropriate mode.

Emergency Lighting Calculator — BS 5266 Luminaire Layout

Calculate emergency light placement, spacing and quantities per BS 5266-1 for escape routes, open areas and high-risk zones.

Room / Route Length

Longest dimension or total escape route length

Room / Route Width

Width of room or escape route

Area TypeDetermines lux requirement and spacing

Mounting Height

Height of emergency luminaires above floor

Luminaire TypeType of emergency luminaire

Number of Exits

Exit signs required for each exit

Battery DurationBS 5266-1: 3 hours for sleeping/complex premises

How We Calculate This

This calculator determines emergency lighting requirements based on BS 5266-1 (the code of practice for emergency lighting). It considers the area type, room dimensions, mounting height and escape route requirements to calculate luminaire quantities and spacing.

How it works

Room type: Different areas have different minimum lux requirements and spacing rules. Escape routes need 1 lux; open areas need 0.5 lux; high-risk areas need 10% of normal lighting.
Spacing: Maximum spacing between luminaires is calculated based on mounting height and the luminaire output. Typically 3-4 times the mounting height for standard LED emergency luminaires.
Additional positions: Luminaires are added at safety equipment locations (fire alarm panel, extinguishers, first aid points).
Exit signs: One illuminated exit sign per exit point, visible from the escape route approach.

Key standards

BS 5266-1: Emergency lighting — Code of practice for the emergency lighting of premises
BS EN 1838: Lighting applications — Emergency lighting
BS EN 60598-2-22: Luminaires for emergency lighting