Life safety systems
Emergency lighting — what it is, where it goes, and how it is designed
Emergency lighting is the lighting that comes on when the normal supply fails, so people can see well enough to leave the building safely, find the fire equipment and avoid panic. In the UK it is designed to BS 5266-1:2016, lit to the levels in BS EN 1838:2013, tested to BS EN 50172, and wired as a safety service under Chapter 56 of BS 7671:2018+A4:2026.
This page explains the system in plain English, then gives an interactive designer that builds a schematic layout and a downloadable A4 PDF design record.
Why it exists
When the mains lighting fails during a fire, a flood or a fault, an unlit corridor becomes an obstacle course. Emergency lighting keeps enough light on the floor to identify the route, see the steps, read the signs and reach the fire equipment — and stops the panic that darkness causes in an occupied room.
What it is not
It is not standby lighting (which lets work carry on) and it is not a torch in a cupboard. It must operate automatically on failure of the normal supply to the local final circuit — not only on a whole-building failure — and it must be independent of the failed supply.
Who is responsible
The responsible person under the Fire Safety Order — usually the employer, building owner, landlord or managing agent. The duty covers provision, testing, record-keeping and repair, and it is enforced by the local fire and rescue authority.
How to recognise emergency lighting
Most people walk past emergency lighting every day without noticing it. These are the giveaways.
Visual clues
- • A small green or red LED indicator that stays lit even when the light is off — that is the charge indicator.
- • A green running-man sign over a door, either a lit box or a legend lit by a nearby fitting.
- • A little recessed key slot or push-to-test button on the fitting or on a nearby wall plate.
- • A small round bulkhead or downlight with an “M” or “NM” label and a duration mark such as 3h.
- • Twin-spot lights on a rectangular battery box — common in plant rooms, car parks and stairwells.
- • A luminaire that stays on when everything else in the room goes out during a test.
Reading the classification code
BS EN 60598-2-22 requires each luminaire to be marked with a code, for example X M F 180 — a self-contained, maintained, self-testing luminaire with a three-hour duration.
- X
- Type — X = self-contained, Z = centrally supplied
- Mode
- 0 = non-maintained, 1 = maintained, 2 = sustained non-maintained, 3 = sustained maintained
- Facility
- A = includes test device, B = remote test mode, C = inhibiting mode, D = high-risk area luminaire, E = non-replaceable lamp, F = self-test, G = self-test + monitoring
- Duration
- 10, 60, 120 or 180 minutes
The different types and how they look
Non-maintained (mode NM)
Off during normal use, illuminates only when the normal lighting supply to that area fails. The standard choice for offices, workshops, shops, schools and the common parts of flats where the building is lit and occupied only when the mains lighting is on.
Maintained (mode M)
Lit continuously from both the normal supply and the battery. Required where people may be present while the normal lighting is deliberately dimmed or switched off — cinemas, theatres, function rooms, licensed premises and places of assembly. All illuminated exit signs in those premises are maintained.
Sustained / combined
A luminaire with two lamps or two LED sets: one on the normal supply, one on the emergency battery supply. Often used where a fitting must serve as both general lighting and emergency lighting.
Self-contained (single point)
Battery, charger, inverter and lamp all inside the fitting. Simplest to install and to extend, no fire-rated sub-circuit wiring needed, but every battery ages independently and must be tested and replaced individually (typically 4–5 years).
Central battery system (CBS)
One central battery (usually a sealed lead-acid or LiFePO₄ bank) supplies many slave luminaires over fire-rated cable. Longer battery life, one maintenance point, but the wiring must maintain circuit integrity and the battery room needs ventilation and its own protection.
Escape route signs
Internally or externally illuminated signs to BS EN ISO 7010 (running man). Internally illuminated signs may be viewed at 200 × the height of the pictogram; externally illuminated signs at 100 × the pictogram height.
Standby lighting
Not emergency escape lighting. Standby lighting allows normal activities to continue substantially unchanged during a supply failure. It only counts as emergency lighting if it also meets BS EN 1838.
Drawing symbols used on the schematic
Design levels — BS EN 1838:2013
| Area | Minimum illuminance | Uniformity / notes |
|---|---|---|
| Escape route ≤ 2 m wide | 1 lux on the centre line | Max:min ≤ 40:1 along the centre line; 0.5 lux across the central band |
| Open / anti-panic area | 0.5 lux over the core area | Excluding a 0.5 m border; applies above 60 m²; max:min ≤ 40:1 |
| High-risk task area | 10% of normal maintained lux, minimum 15 lux | Max:min ≤ 10:1; full output within 0.5 s |
| External area at a final exit | 1 lux to the place of safety | Do not stop at the threshold |
Response times & duration
50% of the required illuminance within 5 seconds and 100% within 60 seconds (0.5 seconds for high-risk task areas). Rated duration is a minimum of 1 hour where the premises are evacuated immediately and not reoccupied until the batteries are recharged; 3 hours for sleeping accommodation and anywhere that may be reoccupied without a recharge. In practice, most UK designs are specified at 3 hours.
Where luminaires must be sited
BS 5266-1 lists the “points of emphasis”. A luminaire is needed within 2 m horizontally of each of these:
- At each final exit door and each exit door intended for escape.
- Near (within 2 m horizontally of) each flight of stairs, so each tread receives direct light.
- Near any other change of level.
- At every change of direction in an escape route.
- At every corridor intersection.
- Outside and near each final exit, illuminating the route to a place of safety.
- At each fire alarm call point.
- At each item of firefighting equipment — extinguishers, hose reels, dry riser inlets.
- At each first-aid point.
- In lift cars and in lift lobbies.
- In escalators and moving walkway areas.
- In toilets over 8 m², all accessible/disabled WCs, and any toilet without borrowed light.
- In motor / generator / control / plant rooms.
- In covered car parks, along the pedestrian routes to the exits.
- In refuges and at refuge call points.
- In areas over 60 m², and in any area where people may be trapped in darkness.
Testing regime and record-keeping
BS EN 50172 / BS 5266-8 sets the minimum routine. The duty to make sure it actually happens sits with the building's responsible person, not with the contractor.
Daily (central systems)
Visually check the central system indicators are showing normal operation. No test required for self-contained fittings beyond noticing a failed charge LED.
Monthly
Simulate a supply failure to every luminaire and sign for long enough to check each one lights (BS EN 50172). Restore the supply and confirm every charge indicator returns. Record the result and any failures in the log book.
Annually
Full rated-duration test — normally the complete three hours — at a time when the building can be recharged before reoccupation. This must be completed by a competent person, usually an electrician, although a trained individual with the right knowledge and experience can also carry it out. Record the date, duration, results, remedial work and the person carrying it out.
The client's responsibilities
Under the Regulatory Reform (Fire Safety) Order 2005 the responsible person — the employer, building owner, landlord or managing agent — must keep the emergency lighting in efficient working order and in good repair. Paul can carry out the tests and issue the paperwork, but the legal duty stays with the client.
- Appoint a named competent person to hold the log book and manage the system.
- Make sure the monthly function test and annual full-duration test are actually carried out, either in-house or by an appointed contractor.
- Keep the log book (paper or digital) on site and available to the fire and rescue authority on request, with test dates, results, defects and remedial action.
- Schedule the annual three-hour test when the building can be left unoccupied long enough for the batteries to recharge fully afterwards.
- Report and arrange repair of failed luminaires, failed charge indicators and damaged signs without delay — a failure found and not fixed is the bigger problem.
- Tell the contractor about any change of layout, new partitions, changed exit routes, new plant rooms or changes of use, because the design will need reviewing.
- Keep escape routes, exit signs and luminaires unobstructed and clean, and never remove or isolate a fitting to 'stop the LED flashing'.
- Retain the original design record, commissioning certificate and any subsequent verification certificates for the life of the installation.
- Budget for battery replacement — most self-contained batteries have a design life of around four years and will fail the duration test before they fail the function test.
- Include emergency lighting in the fire risk assessment and review it whenever the assessment is reviewed.
Where testing is delegated to a contractor, put it in writing — the responsible person remains accountable for making sure it is done and the records exist.
Legal documents and standards
Article 14(2)(h) — emergency routes and exits requiring illumination must be provided with emergency lighting of adequate intensity in case of failure of their normal lighting. Article 17 — the responsible person must keep it maintained in efficient working order and in good repair.
Clarify and extend the responsible person's duties in multi-occupied residential buildings, including the common parts where escape lighting normally sits.
Sets where escape lighting is expected in dwellings and in buildings other than dwellings, and refers to BS 5266-1 for the design.
Code of practice for the emergency escape lighting of premises. The UK application standard — durations, siting, system selection, commissioning, log book and certification.
Lighting applications — emergency lighting. The photometric standard: 1 lux escape route centre line, 0.5 lux anti-panic core area, 15 lux or 10% for high-risk tasks, uniformity, glare limits and sign viewing distances.
Emergency escape lighting systems — the testing, servicing and record-keeping standard. Monthly function test, annual full-duration test, log book.
Product standard for luminaires for emergency lighting, including classification codes and the requirement to mark the mode and duration.
Safety services. Sources, segregation, circuit protection, wiring systems with circuit integrity for central systems, and the requirement that emergency lighting circuits are clearly identified at the distribution board.
Automatic test systems for battery-powered emergency escape lighting — the standard behind self-testing and addressable monitored systems.
Registered safety signs — the running-man pictogram set used on all UK escape signage.
British Standards are copyright documents and must be purchased from BSI. The links go to the publisher or to legislation.gov.uk, never to unlicensed copies.
Design tool
Emergency lighting design schematic & PDF
Add each area of the building, set its classification and dimensions, and the tool produces the planning spacing, luminaire grid, schematic plan and a full A4 PDF design record with the standards, points of emphasis and sign-off block. Everything runs in your browser — nothing is uploaded.
Project details
Areas
Points of emphasis in this area
Target illuminance
1.0 lux
Planning spacing
9.6 m
Grid
3 × 1
Total luminaires
6
Points of emphasis in this area
Target illuminance
0.5 lux
Planning spacing
8.1 m
Grid
3 × 2
Total luminaires
7
Points of emphasis in this area
Target illuminance
1.0 lux
Planning spacing
9.6 m
Grid
2 × 1
Total luminaires
7
- • Each flight of stairs needs a direct light on the treads.
3 areas · 171.0 m² · 20 emergency luminaires
Produces an A4 PDF with the project details, luminaire schedule, a schematic plan per area, the standards list and a sign-off block.
Disclaimer — no liability
This tool is an indicative planning aid. Spacings are generic multipliers of mounting height, not a photometric calculation. Every layout must be verified by a competent person against the manufacturer’s photometric spacing tables, the building’s fire strategy and the current editions of BS 5266-1:2016, BS EN 1838:2013, BS EN 50172 and BS 7671:2018+A4:2026.
All Cabling© Limited accepts no liability whatsoever for any loss, damage, injury, cost or non-compliance arising directly or indirectly from use of, or reliance on, this tool or its output. By using it you accept these terms in full.