BS 5266 Emergency Lighting: The Complete UK Guide

BS 5266 is the British Standard code of practice for the emergency lighting of premises. The primary document is BS 5266-1:2025 — Emergency lighting. Code of practice for the emergency lighting of premises — which provides guidance on the design, installation, wiring, testing, and maintenance of emergency lighting systems in buildings. The standard was revised in 2025 from the previous 2016 edition; any reference to "BS 5266-1" in specifications or contracts should be understood to mean the current 2025 edition. It works alongside the European standard BS EN 1838, which specifies the minimum illuminance levels and design parameters.

Emergency lighting is the lighting that operates when the normal mains-powered lighting fails. Its purpose is to enable the safe evacuation of a building, to illuminate fire safety equipment (extinguishers, call points, fire exits), and to allow high-risk processes to be safely shut down. Without adequate emergency lighting, a power failure in a building at night or in a windowless space could leave occupants in complete darkness — creating a serious risk of injury from falls, collisions, and panic.

For electricians, emergency lighting is a core competence area. It features in domestic work (HMOs, blocks of flats), commercial work (offices, shops, warehouses), and industrial work (factories, plant rooms). Understanding BS 7671 alone is not enough — you also need to understand BS 5266-1:2025 and BS EN 1838 to design and install emergency lighting systems correctly.

Emergency lighting is a legal requirement in the UK under several overlapping pieces of legislation:

Failure to provide or maintain adequate emergency lighting is an offence under the Fire Safety Order 2005 and can result in enforcement notices, prohibition notices, and prosecution. In the event of a fire in which occupants are injured because of inadequate emergency lighting, the responsible person could face criminal charges including corporate manslaughter in the most serious cases.

Emergency lighting is not just a fire-safety discipline — it is a wiring discipline governed by BS 7671:2018+A4:2026. Three regulations are particularly important for electricians installing or inspecting these systems.

When carrying out an EICR on a premises with emergency lighting, check that the system wiring is correctly segregated and that the circuit is identified on the distribution board schedule. Missing identification or mixed-circuit containment should be recorded as an observation code C2 or C3 depending on the risk presented.

Escape route lighting is the most critical component of an emergency lighting system. Its purpose is to illuminate the escape routes so that occupants can see where they are going during an evacuation. BS EN 1838 sets out the specific illuminance requirements:

Emergency luminaires on escape routes should be positioned at every change of direction, at every change of floor level (stairways), at every intersection of corridors, at each final exit, immediately outside each final exit, near each first aid post, near each fire-fighting equipment point, and near each manual call point.

The positioning of luminaires is critical to achieving the uniformity requirement. Placing luminaires too far apart will create dark zones between them, while placing them too close together wastes equipment and increases maintenance costs. BS 5266-1:2025 provides guidance on luminaire spacing based on the mounting height and the light output of the luminaire.

Open area lighting (also called anti-panic lighting) is required in large open areas such as open-plan offices, shop floors, assembly halls, sports halls, and similar spaces exceeding 60m² in floor area. The purpose is to prevent panic and provide enough illumination for occupants to identify the escape routes and move safely towards them.

Open area lighting is often achieved by converting a proportion of the normal room luminaires to emergency operation (maintained or non-maintained with battery back-up packs). The designer must calculate how many luminaires need emergency conversion to achieve the 0.5 lux minimum across the area. Emergency lighting design software or manufacturer spacing tables are used to verify the design.

High-risk task area lighting is required where a sudden loss of normal lighting would create a direct hazard to the safety of the occupants. This applies to any work activity that involves a significant risk of injury if the lights go out — for example:

The illuminance requirement for high-risk task areas is significantly higher than for escape routes. BS EN 1838 specifies a minimum of 10% of the normal task illuminance or 15 lux, whichever is greater. The uniformity ratio must not exceed 10:1 (much tighter than the 40:1 for escape routes). The light must reach the required level within 0.5 seconds of mains failure — much faster than the 5-second requirement for escape routes.

This high requirement means that high-risk task area emergency lighting often needs higher-output luminaires with fast-response light sources (LEDs are ideal for this as they reach full output virtually instantly).

Standby lighting is not strictly part of the emergency escape lighting system, but it is covered by BS 5266-1:2025. Standby lighting is provided to enable normal activities to continue during a mains power failure. It is used in situations where a complete shutdown is not acceptable — for example:

Standby lighting is typically powered by a generator or central battery system with an automatic changeover switch. The illuminance level for standby lighting is determined by the specific requirements of the activity — it is often the same as the normal lighting level. The standby lighting system must be designed to integrate with the emergency escape lighting so that both systems can operate simultaneously during a mains failure.

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Emergency lighting systems fall into two primary architectures. Understanding the difference is essential for correct design, installation, and certification.

Regular testing of emergency lighting is essential to ensure the system will function when needed. BS 5266-1:2025 defines a clear testing schedule:

Many modern self-contained emergency luminaires include automatic self-test functionality. These luminaires automatically carry out a brief functional test (30 seconds to 1 minute) at regular intervals and a full duration test once a year. The results are indicated by LED status lights on the luminaire. Self-testing luminaires reduce the manual testing burden but do not eliminate it entirely — the results must still be checked and recorded.

All test results must be recorded in an emergency lighting log book, which should be kept on the premises and available for inspection by the fire authority. The log book should record the date, time, type of test, results, and any remedial action taken.

Proper documentation is essential for emergency lighting systems. Clients need test certificates to demonstrate compliance with the Fire Safety Order, and the fire authority can request evidence of regular testing at any time. Elec-Mate provides everything you need to manage emergency lighting work efficiently:

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