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Maintained vs Non-Maintained Emergency Lighting: UK Guide
Updated October 2026 · Meteor Electrical guides · 11 min read
Quick answer: A non-maintained emergency light stays off while the mains supply is healthy and switches on from its battery only when the normal lighting fails. A maintained emergency light is lit all the time and carries on from its battery in a power cut. Non-maintained suits offices, factories and other places where people know the building; maintained suits theatres, cinemas, shops and other public spaces, and illuminated exit signs.
Choosing between maintained and non-maintained emergency lighting is one of the first decisions in any emergency lighting design. This guide explains how each mode works, where it is used, when you need 1 hour or 3 hour duration, and how to test your system under BS 5266-1.
In this guide
- What is emergency lighting?
- What is the difference between maintained and non-maintained emergency lighting?
- Where should you use maintained or non-maintained emergency lights?
- 1 hour or 3 hour emergency lighting: which duration do you need?
- Escape route vs open area lighting: what is the difference?
- How do you test emergency lighting under BS 5266-1?
- What should you check before buying emergency lights?
- FAQs
What is emergency lighting?
Emergency lighting is lighting that comes on automatically when the normal supply fails, so people can find their way out of a building safely and quickly. Each fitting has its own battery or is fed from a central battery system, and it is designed to work for a set duration, usually 1 or 3 hours.
In the UK, emergency lighting is designed, installed and maintained to BS 5266-1, the code of practice, with minimum light levels set by BS EN 1838. In the Republic of Ireland the equivalent standard is I.S. 3217. Most non-domestic premises need it as part of their fire risk assessment, and a "responsible person", usually the employer, owner or managing agent, must keep it working. Gov.uk has a clear summary of workplace fire safety responsibilities.
Emergency lighting falls into two broad groups. Emergency escape lighting helps people leave the building, and standby lighting lets normal activities carry on during a power cut. This guide is about escape lighting, which is what the regulations require.
What is the difference between maintained and non-maintained emergency lighting?
The difference is simply whether the lamp is lit when the mains supply is healthy. Both types charge their batteries from the mains and both light up in a power cut. The mode you choose depends on who uses the building and whether the normal lighting can be switched off or dimmed while people are inside.
Non-maintained emergency lighting
A non-maintained emergency light is dark in normal use. Its battery charges from a permanent, unswitched supply, and when that supply fails the fitting switches over to battery within a fraction of a second. It is wired from the same final circuit as the local normal lighting, so if that lighting circuit fails, the emergency light comes on too.
Non-maintained fittings are the most common choice for offices, warehouses, factories, schools and common areas of flats, where the people inside know the layout and the main lighting stays on while the building is occupied. They draw only a small charging current in normal use. Browse our non-maintained emergency lights for bulkheads, downlights and conversion modules.
Maintained emergency lighting
A maintained emergency light works as a normal light and as an emergency light. It is lit all the time the building is occupied, usually from a switched live, and it keeps running from its battery when the supply fails. Because it is always on, people already know where the lights and exit signs are.
BS 5266-1 calls for maintained lighting in places where the normal lighting can be dimmed or switched off while people are present, such as theatres, cinemas, nightclubs and bars. It is also common in shops, leisure centres and other public buildings where visitors do not know the layout, and for illuminated exit signs that must be visible at all times.
Sustained (combined) emergency lighting
A sustained or combined emergency light contains two or more lamps. One runs from the mains in normal use and the other runs from the battery in an emergency. In practice it behaves like a maintained fitting. Many modern LED fittings are switchable, so the installer can set them to maintained or non-maintained on site.
| Feature | Non-maintained | Maintained | Sustained / combined |
|---|---|---|---|
| Lit in normal use? | No | Yes | Yes (mains lamp) |
| Lit in a power cut? | Yes, from battery | Yes, from battery | Yes (emergency lamp) |
| Typical supply | Permanent live only | Permanent live plus switched live | Permanent live plus switched live |
| Energy use | Charging current only | Lamp power plus charging | Lamp power plus charging |
| Typical locations | Offices, factories, warehouses, schools, corridors | Theatres, cinemas, bars, shops, public buildings, exit signs | Exit signs and public areas |
| Standard | BS 5266-1 and BS EN 1838 | BS 5266-1 and BS EN 1838 | BS 5266-1 and BS EN 1838 |
Pro tip: An exit sign is not automatically non-maintained. In public buildings and anywhere the lighting may be dimmed, exit signs are normally maintained so they stay visible at all times. Signs must use the green running-man pictogram to BS EN ISO 7010.
Where should you use maintained or non-maintained emergency lights?
Your fire risk assessment and emergency lighting design decide the mode, duration and layout. As a general guide:
| Premises | Usual mode | Usual duration |
|---|---|---|
| Offices and workplaces | Non-maintained, with maintained exit signs where needed | 1 hour or 3 hours |
| Factories and warehouses | Non-maintained | 1 hour or 3 hours |
| Shops and shopping centres | Maintained in public areas | 3 hours |
| Theatres, cinemas, bars and nightclubs | Maintained | 3 hours |
| Hotels, care homes and other sleeping risks | Non-maintained escape lighting, maintained signs | 3 hours |
| Common areas of flats and HMOs | Non-maintained | 3 hours |
| Homes | Not normally required | Optional |
Emergency lighting is not usually required in a private house, but a non-maintained fitting on the stairs or a plug-in torch can still be useful in a power cut.
Self-contained, central battery and conversion modules
- Self-contained: each fitting has its own battery and charger. This is the usual choice for small and medium buildings.
- Central battery: one battery system feeds many fittings through fire-resistant cable. It is used on larger sites where batteries are easier to manage in one place.
- Emergency conversion modules: a battery and module added to a standard LED fitting, so a panel, batten or high bay can double as an emergency light.
- Satellite fittings: extra fittings powered from a nearby self-contained unit.
Our range includes Kosnic emergency lighting, with bulkheads, downlights, exit boxes and emergency modules for high bays and LED panels.
1 hour or 3 hour emergency lighting: which duration do you need?
The duration is how long the fitting must keep giving its rated light output from the battery. BS EN 1838 sets a minimum of 1 hour for escape route lighting, but BS 5266-1 recommends 3 hours for most premises.
- 1 hour is only acceptable where the building is evacuated straight away when the supply fails and is not reoccupied until the normal supply returns and the batteries have recharged.
- 3 hours is recommended for premises with sleeping accommodation, such as hotels, care homes and HMOs, for places of entertainment, and for any building where people may stay or come back in before the power is restored.
Because 3 hour fittings cover both cases and cost little more, they are the default choice for most new installations. If you are unsure, check the fire risk assessment or ask your designer.
Escape route vs open area lighting: what is the difference?
BS EN 1838 and BS 5266-1 split escape lighting into types, each with a minimum light level:
| Type | What it does | Minimum level |
|---|---|---|
| Escape route lighting | Lights the defined route to the exits, including corridors and stairs | 1 lux along the centre line of the route |
| Open area (anti-panic) lighting | Lights larger rooms so people can reach an escape route, typically areas over 60 m² | 0.5 lux across the floor area |
| High-risk task area lighting | Lets people make a dangerous process safe before leaving | 10% of normal lighting, and at least 15 lux |
Fittings must also be placed at "points of emphasis": near each exit door, at every change of direction, near stairs and changes of floor level, at fire alarm call points, firefighting equipment and first aid points, and outside each final exit.
How do you test emergency lighting under BS 5266-1?
BS 5266-1 requires regular testing, with every result recorded in an emergency lighting logbook. There are two routine tests.
Monthly function test
- Simulate a supply failure using the test key switch, which cuts the charging supply to the emergency fittings while the normal lighting stays on.
- Walk the building and check that every emergency light and sign comes on from its battery.
- Restore the supply and check that the charging indicators come back on.
- Record the date, the result and any faults in the logbook, and arrange repairs.
Keep the test brief, just long enough to check every fitting. An emergency light test switch lets you do this without switching off the lighting circuit.
Annual full-duration test
- Choose a quiet time, as the batteries will be flat afterwards and can take up to 24 hours to recharge.
- Simulate a supply failure and leave it for the full rated duration of the fittings, either 1 or 3 hours.
- Check that every fitting is still lit at the end of the test.
- Replace any battery or fitting that fails, then record the results in the logbook.
Credit: Optimal Fire & Security Ltd.
Self-test emergency lights
Self-test fittings run their own function and duration tests automatically and show the result on an indicator LED, which cuts the time spent walking the building with a test key. Some, such as the Kosnic Belum self-test LED exit box, are a simple swap for a manual fitting. Larger sites can use DALI or addressable systems that report back to a central panel.
Self-test fittings still need someone to check the indicators regularly, keep the logbook and act on any faults.
What should you check before buying emergency lights?
- Mode: maintained, non-maintained or switchable, to suit the area.
- Duration: 3 hours for most premises, unless the design allows 1 hour.
- Light output: enough emergency lumens for the spacing in your design. LED fittings give good output from small batteries.
- Testing: manual test, self-test or DALI, depending on the size of the site.
- IP rating: IP65 bulkheads for outdoor exits, car parks and damp areas.
- Signage: exit signs with the correct ISO 7010 pictogram and viewing distance.
Safety: Emergency lighting is life-safety equipment. The design, installation and certification should be carried out by a competent electrician to BS 5266-1 and BS 7671 (or I.S. 3217 and I.S. 10101 in Ireland), and the responsible person must keep it tested and recorded.
Key takeaways
- Non-maintained emergency lights stay off until the mains supply fails. Maintained emergency lights are lit all the time and carry on from battery.
- Use maintained lighting where normal lighting can be dimmed or switched off, and in public buildings. Non-maintained suits most workplaces.
- BS 5266-1 recommends 3 hour duration for most premises. 1 hour is acceptable only where the building is evacuated immediately and not reoccupied.
- Test monthly with a short function test and annually with a full-duration test, and record everything in a logbook.
- Escape routes need at least 1 lux on the centre line, open areas 0.5 lux.
Choosing the right non-maintained or maintained emergency light
For most offices, factories and common areas, non-maintained emergency lights with 3 hour duration are the practical choice, with maintained exit signs where they need to stay visible. Public buildings and anywhere the lighting can be dimmed need maintained fittings. Whichever you choose, plan the layout to BS 5266-1 and keep up the monthly and annual tests. For more on commercial schemes, see our guide to choosing emergency lighting for commercial buildings.
Shop emergency lighting
Maintained, non-maintained and self-test emergency lights, exit signs and conversion modules. Trade prices, next working day delivery across NI & ROI on in-stock orders before 5pm.
Shop emergency lighting Shop KosnicNeed help choosing? Call our team on 028 8675 1515 (048 from ROI), Monday to Friday, 8am–5pm.
FAQs
What is a non-maintained emergency light?
A non-maintained emergency light stays off while the mains supply is working and switches on automatically from its built-in battery when the normal lighting fails. It is the most common type in offices, factories and warehouses, where people know the building and the main lights stay on while it is occupied.
What is the difference between maintained and non-maintained emergency lighting?
Maintained emergency lights are lit all the time and keep running from their battery in a power cut. Non-maintained lights only come on when the supply fails. Maintained lighting is used where normal lighting can be dimmed and in public buildings, while non-maintained suits most workplaces.
Do emergency lights need to be 3 hour?
BS 5266-1 recommends 3 hour emergency lighting for most premises, including anywhere with sleeping accommodation or places of entertainment. 1 hour is only acceptable where the building is evacuated immediately on supply failure and not reoccupied until the power returns and the batteries have recharged.
How often should emergency lighting be tested?
Under BS 5266-1, emergency lighting should have a short function test every month, using a test key to simulate a power cut, and a full rated duration test once a year. Every test, fault and repair should be recorded in the emergency lighting logbook kept by the responsible person.
Are exit signs maintained or non-maintained?
Exit signs can be either, but in public buildings, places of entertainment and anywhere the lighting may be dimmed they are normally maintained so they are always visible. Many modern LED exit signs are switchable, so the installer can set the mode on site to suit the area.
What is a self-test emergency light?
A self-test emergency light carries out its own monthly function test and annual duration test automatically, then shows the result on an indicator LED. It saves time on larger sites, but someone still needs to check the indicators regularly, record the results in the logbook and fix any faults.
Do I need emergency lighting in my house?
Emergency lighting is not normally required in a single private house. It is usually needed in the common areas of flats, houses in multiple occupation and all non-domestic premises. Homeowners may still fit a non-maintained light on the stairs for safety during power cuts.