When the mains power fails in a commercial building, your emergency lighting system becomes the difference between a safe evacuation and a dangerous situation. For architects, lighting designers and electrical engineers working on UK commercial projects, getting emergency lighting design right means navigating British Standards, building regulations and practical installation challenges.
This guide walks you through everything you need to know about designing compliant emergency lighting systems for commercial buildings in the UK. From the latest BS 5266-1:2025, BS EN 1838:2024 and BS EN 50172:2024 requirements to selecting the right luminaires and testing systems, 299 Lighting has drawn on our experience delivering emergency lighting design across thousands of commercial fit-outs to bring you practical, specification-ready guidance.
Emergency lighting activates when the normal mains power supply fails, allowing building occupants to evacuate safely. In commercial buildings, this means illuminating escape routes, exit doors, fire alarm call points and firefighting equipment so people can see hazards, changes in level and directional signage.
Beyond evacuation, emergency lighting serves several additional purposes. It reduces panic in enclosed spaces and high-occupancy areas. It enables occupants to safely shut down dangerous processes before evacuating. It can provide local area lighting for people who are allowed to remain temporarily in part of a building. And it can allow certain activities to continue through standby lighting if evacuation is not required.
The Regulatory Reform (Fire Safety) Order 2005 makes it a legal requirement for non-domestic premises to provide emergency lighting where needed. As the building's Responsible Person, you carry the duty to ensure systems are properly designed, installed and maintained.
Emergency lighting design in the UK sits at the intersection of several key standards and regulations. Understanding how these fit together helps you specify systems that meet compliance requirements while supporting your design intent.
| Standard | What it covers |
|---|---|
| BS 5266-1:2025 | UK code of practice for design, installation, wiring, certification and routine testing |
| BS EN 1838:2024 | Lighting requirements: lux levels, uniformity, response times and duration |
| BS EN 50172:2024 (BS 5266-8:2024) | Installation, commissioning, verification, testing, maintenance and documentation |
| BS EN 60598-2-22 | Construction and performance of emergency luminaires |
| BS EN 62034 | Automatic test systems for battery-powered emergency escape lighting |
BSI published the fully revised BS 5266-1:2025 on 29 October 2025, replacing the 2016 edition. This standard now covers three distinct types of emergency lighting:
The expanded scope reflects modern building use. In many commercial premises, evacuation is not the only consideration. Some occupants may need to remain in place, or essential operations may need to continue safely.
BS EN 1838:2024 replaced the 2013 edition and sets the luminous requirements your design must achieve. Its most significant change for designers is that escape route illuminance is now assessed across the width of the route rather than along the centre line. It also introduces local area lighting as a defined category and adds considerations for prolonged shutdowns and recommissioning.
BS EN 50172:2024, also published as BS 5266-8:2024, replaces the 2004 edition. It has been completely rewritten, with expanded commissioning, testing and recording procedures, new requirements for handover documentation and automatic test systems, and references to newer battery technologies.
The CIBSE Lighting Guide 12 (2022) complements BS 5266-1 by providing detailed design guidance for practitioners. LG12 covers risk assessment methodology, design calculations, equipment selection and the commissioning process.
As the guide notes, emergency lighting is not a complex lighting design problem, but it is a difficult design management problem. Premises must remain compliant throughout their occupied life, requiring careful coordination between designers, installers and building operators.
This order places the legal responsibility for fire safety, including emergency lighting, on the Responsible Person. In most commercial buildings, this is the employer, owner or occupier who has control over the premises.
The Responsible Person must ensure emergency routes and exits requiring illumination are fitted with emergency lighting of adequate intensity. They must also maintain systems in proper working order and arrange for regular testing in accordance with BS 5266-1 and BS EN 50172.
Before specifying any emergency lighting system, you need to carry out a risk assessment. This determines the category of premises, the hazard level, and the degree of occupant familiarity with escape routes.
Your assessment should evaluate building layout and escape route complexity, occupancy levels and characteristics, activities carried out in different areas, normal lighting conditions when occupied, whether anyone will remain in the building during a lighting failure, and the potential consequences of lighting failure in each zone.
Buildings where occupants are unfamiliar with the layout, such as hotels, shopping centres and entertainment venues, typically require more extensive emergency lighting than workplaces where staff know the escape routes well.
The risk assessment should produce documentation showing proposed escape routes, escape route signs, locations of fire alarm call points and firefighting equipment, open areas requiring anti-panic lighting, high-risk task areas, areas needing local area lighting, special locations such as toilets and lift cars, and the rated duration required. This documentation supports your emergency lighting design and demonstrates due diligence to fire safety inspectors.
BS EN 1838:2024 and BS 5266-1:2025 set the minimum illumination levels your emergency lighting must achieve. All values are minimums at the end of the rated duration, so your design must allow for worst-case conditions over the life of the installation.
| Application | Minimum illuminance | Notes |
|---|---|---|
| Escape routes | 1 lux at floor level | Across the route width, less the border; uniformity no greater than 40:1 |
| Open areas (anti-panic) | 0.5 lux at floor level | Excluding a 0.5 m perimeter border; uniformity no greater than 40:1 |
| High-risk task areas | 10% of normal illuminance, minimum 15 lux | Full output within 0.5 seconds |
| Points of emphasis | 5 lux vertical | At firefighting equipment, call points, panels, escape and rescue plans and first aid boxes |
| Local area lighting | At least the escape route or open area value | Level set by risk assessment |
Under the previous 2013 edition, escape routes up to 2 metres wide were calculated along the centre line. BS EN 1838:2024 now requires a minimum of 1 lux at floor level across the width of the escape route, with a uniformity ratio no greater than 40:1 to avoid pools of light and dark patches that could obscure hazards.
A border can be excluded from the calculation:
The 2 m width limit has also been removed, so wider routes can now be assessed as a single escape route rather than as open areas. A 4 m route, for example, has a 3 m wide calculation area that must achieve at least 1 lux. In practice, this can mean more luminaires, closer spacing or higher-output fittings than a scheme designed to the 2013 method, so legacy spacing tables and design templates should be checked.
Where an escape route passes through an open area but is not physically defined, the whole open area should be treated as an escape route. Where a defined route passes through it, the route should receive at least 1 lux at floor level, as summarised by NICEIC.
Stairs present an increased hazard during evacuation. An emergency luminaire should be positioned so that each flight of stairs receives direct light, with every tread illuminated, and luminaires should be placed at each change of floor level, including ramps. This helps occupants see steps, handrails and changes of direction clearly.
Open areas that are not part of a designated escape route still need emergency lighting to prevent panic and allow people to reach an escape route. This includes larger open-plan spaces and any smaller areas identified by the risk assessment. The minimum illumination is 0.5 lux at floor level across the area, excluding a 0.5 m border at the perimeter, with a uniformity ratio no greater than 40:1.
Where occupants are involved in potentially dangerous activities, such as in laboratories, commercial kitchens or plant areas, high-risk task area lighting allows safe shutdown procedures before evacuation. It must provide at least 10% of the normal maintained illuminance, and not less than 15 lux, reaching full output within 0.5 seconds. BS 5266 now requires luminaires in high-risk areas to be wired from at least two separate circuits, with no more than 20 luminaires affected by a single circuit fault, according to the ECA.
BS 5266-1:2025 recommends a minimum vertical illuminance of 5 lux at firefighting equipment, call points, panels, escape and rescue plans and first aid boxes. It also adds recommendations for accessible and baby-changing toilets, lift alarm points, corridors from lifts to escape routes and public indoor swimming pools (NICEIC). Escape routes, toilets and changing rooms should be covered by at least two luminaires, one of which may be an internally illuminated safety sign, so a single failure does not leave the space in darkness (The Light Review).
Escape lighting must reach 50% of the required illuminance within 5 seconds and full illuminance within 60 seconds. For most commercial premises, the rated duration is 3 hours. A 3-hour duration is needed for sleeping accommodation, entertainment venues, premises with phased evacuation and any building that may be reoccupied before the batteries have fully recharged. One hour may be acceptable in some premises where evacuation is immediate and the building is not reoccupied straight away, but this must be justified by the risk assessment.
Choosing between maintained and non-maintained fittings is one of the most important decisions in emergency lighting design. The right choice depends on building type, occupancy patterns and normal lighting conditions.
Maintained fittings operate continuously as part of normal room lighting. They run on mains power during normal operation but switch to battery backup when power fails, continuing to provide illumination at a reduced output level.
Maintained lighting is required in premises where normal lighting is routinely dimmed or switched off while occupied. This includes cinemas, theatres, nightclubs and bars. It is also commonly used in public assembly buildings like shopping centres and leisure facilities where occupants may be unfamiliar with escape routes.
Non-maintained fittings remain off during normal operation. They only illuminate when the mains power fails, powered by batteries that are kept charged from the mains supply. These fittings are typically used in workplaces like offices, factories and schools where occupants are familiar with the building and escape routes are clearly visible under normal lighting.
Non-maintained systems have lower energy consumption since they only operate during emergencies. This makes them a practical choice where maintained lighting is not specifically required.
Sustained fittings include two separate light sources: one operating on mains supply for normal lighting, and another that activates from battery supply during power failure. Combined or switchable fittings can operate in either maintained or non-maintained mode, offering flexibility for buildings with mixed requirements.
Effective emergency lighting design places luminaires where they provide maximum safety benefit. The positioning requirements are specified in BS 5266-1 and BS EN 1838, and should be verified through spacing tables or lighting calculations.
Emergency luminaires must be positioned at or near each exit door, at changes of direction along escape routes, at changes of floor level including stairs and ramps, at intersections of corridors, outside and near each final exit, and near first aid posts and firefighting equipment.
Additionally, luminaires should be placed near fire alarm call points and safety signs to ensure these can be seen and operated during power failure.
Emergency escape lighting design must be based on worst-case conditions over the life of the installation. This means minimum light output, maximum glare, an appropriate maintenance factor, and direct light only, with no allowance for reflections from walls or ceilings. Borrowed light from sources outside the building's emergency lighting system cannot be relied on and is excluded from BS 5266-1. Calculations should use the emergency light output declared under BS EN 60598-2-22, so the quality of manufacturer photometric data is critical.
Manufacturers publish spacing tables for their emergency luminaires based on mounting height and room geometry. These tables show the maximum distance between fittings while maintaining minimum illumination levels. Check that any spacing tables you use reflect the full-width escape route method in BS EN 1838:2024, as tables based on the older centre-line method can overstate the spacing achievable. For irregular spaces or where spacing tables cannot be applied directly, computer-based lighting calculations are needed.
At 299 Lighting, we support all our emergency lighting products with photometric data, spacing information and LDT files for software calculations. Our team can prepare full emergency lighting calculations for your project, ensuring compliant coverage across all escape routes and open areas.
For central battery systems, BS 5266-1:2025 asks designers to size the supply for the actual load in both watts and VA, including inrush current and power factor. This reflects the growing number of LED luminaires being added to older systems. If the system is modified, these figures should be recalculated and the records updated (NICEIC).
BS EN 1838:2024 adds considerations for lockdowns and long periods without power. Your design and O&M information should include procedures to protect batteries from deep discharge during prolonged shutdowns, and to safely recommission the system afterwards.
The emergency lighting market offers a range of product types suited to different applications. Understanding the options helps you specify fittings that meet both compliance requirements and aesthetic considerations.
Bulkhead luminaires are robust, surface-mounted fittings commonly used in back-of-house areas, plant rooms, car parks and external escape routes. They provide good light output and are available in IP65-rated versions for damp or dusty environments.
Emergency spotlights are compact, discreet fittings with high-efficiency optics designed specifically for escape routes and open areas. Their wide spacing makes them well suited to meeting the full-width escape route requirement with fewer fittings.
For design-led spaces where visible emergency fittings would compromise aesthetics, emergency conversion modules can be integrated into standard downlights. These conversions allow your general lighting to double as emergency lighting, maintaining design intent while meeting compliance. 299 Lighting supplies integrated emergency options across our downlight range, with UK-made conversion kits and four-year warranties.
Modern linear lighting systems can incorporate emergency modules that maintain illumination along the luminaire length during power failure. This approach works well in offices and commercial spaces where linear lighting forms the primary lighting scheme.
Illuminated exit signs are required at every designated exit. These may be maintained (always lit) or non-maintained (lit only during emergency), depending on normal lighting conditions. Signs must comply with safety sign regulations and be positioned to be visible from the relevant escape route. Escape route signs should now be shown on the plans used at consultation and design stage.
Emergency lighting must be tested regularly to confirm it will function when needed. BS EN 50172:2024 sets out the testing, verification and recording requirements, and modern systems offer automated options to reduce the maintenance burden.
| Frequency | What is checked |
|---|---|
| Daily | Visual check of central battery system indicators (central systems only) |
| Monthly | Short functional test to confirm every luminaire and sign operates |
| Annually | Full rated duration test, typically three hours |
| Every 5 years (maximum) | Photometric verification of illuminance levels against the design |
Results must be recorded in a logbook for inspection. Full-duration tests should be carried out at times of low risk, or on alternate luminaires, as the building has reduced protection while batteries recharge.
Photometric performance must now be verified at handover and then at intervals not exceeding five years, to confirm that light levels still match the design (NICEIC). Refits, partition changes, ceiling alterations and ageing equipment can all reduce performance over time, so this should be built into the building's maintenance schedule from day one.
Self-test luminaires incorporate microprocessor controls that automatically perform functional and duration tests at programmed intervals. LEDs or other indicators show pass or fail status, reducing the need for manual intervention. Self-test fittings still require periodic inspection to check indicators, log results and act on faults.
Larger installations often benefit from central test systems that monitor and test all connected luminaires from a single controller. These systems can schedule tests automatically, compile reports and flag faults for maintenance. DALI-2 addressable systems enable sophisticated monitoring and integration with building management systems. Automatic test systems should comply with BS EN 62034, and BS EN 50172:2024 now includes specific requirements for them.
299 Lighting offers emergency fittings with self-test functionality and DALI-2 reporting options, giving you flexibility to match the testing approach to your project requirements and client preferences.
Proper documentation demonstrates compliance and supports the Responsible Person in meeting their legal duties. The design and installation process should produce several key documents.
Your design package should include the emergency lighting risk assessment, escape route drawings with luminaire and sign positions, lighting calculations showing compliance with the BS EN 1838:2024 illumination requirements, product datasheets and photometric data, and a schedule of emergency luminaires with specifications. For central battery systems, include load calculations in both watts and VA.
The installation process produces test certificates confirming electrical safety, commissioning records showing each luminaire functions correctly, an emergency lighting completion certificate, initial photometric verification results and as-installed drawings reflecting any site changes. The results of the commissioning inspections and tests defined in BS EN 50172:2024 should be included in the handover documents, and any intentional variations from BS 5266-1 must be clearly identified and recorded.
Once the system is handed over, the building operator needs an operation and maintenance manual, a test logbook for recording daily, monthly and annual tests, a maintenance schedule with battery replacement intervals and the five-year photometric verification date, and procedures for prolonged shutdowns and recommissioning.
We have been supplying emergency lighting systems and design support since the start of our business. Working alongside architects, consultants and contractors on large-scale CAT A fit-outs and commercial refurbishments, we understand the practical challenges of delivering compliant emergency lighting that integrates with your overall lighting scheme.
Our range includes standalone emergency bulkheads and spotlights, integrated emergency options for linear, suspended and downlight luminaires, self-test modules and DALI-2 reporting systems, and exit signage compliant with British Standards. All products are supported with photometric data, spacing tables and technical specifications.
We offer full emergency lighting design services, including risk assessment support, luminaire spacing calculations to the full-width escape route method, and compliance documentation. Our LIA-accredited Light Engineers can review your scheme, recommend products and prepare the technical submissions needed for building control approval.
Want to know more about what 299 Lighting can do for your project? Our team can take you through all your options to suit your timeline and budget in an initial consultation.
an initial consultation.
Specifications, templates and spacing tables that still reference BS 5266-1:2016, BS EN 1838:2013 or BS EN 50172:2004 can lead to schemes that no longer comply. The most common example is calculating escape routes along the centre line rather than across the full width. Always check that your design basis reflects the current editions.
Relying on general assumptions rather than proper spacing calculations often results in insufficient coverage. Always verify your layout with manufacturer spacing data or calculated lux levels, using worst-case output and direct light only.
Emergency lighting should complement your general lighting design, not conflict with it. Consider how emergency fittings will look alongside your primary luminaires, and explore integrated options where appropriate.
Fittings installed in difficult-to-reach locations make testing, photometric verification and battery replacement problematic. Specify accessible positions or ensure automated testing is specified from the outset.
Failing to produce proper design documentation and handover records leaves the Responsible Person without the evidence needed to demonstrate compliance. Build documentation requirements, including commissioning results and recorded variations, into your project workflow.
Emergency lighting design requires balancing regulatory compliance with practical installation considerations and design intent. The revised BS 5266-1:2025, BS EN 1838:2024 and BS EN 50172:2024 reflect the evolving needs of modern buildings, expanding coverage to include local area and standby lighting, raising the bar on escape route coverage and introducing ongoing photometric verification.
For architects, lighting designers and electrical engineers, getting emergency lighting right means starting with a thorough risk assessment, selecting appropriate luminaires for each application, and producing documentation that supports ongoing compliance. Working with a lighting supplier who understands both the technical requirements and the commercial realities of fit-out projects makes this process more manageable.
At 299 Lighting, we partner with project teams to deliver emergency lighting solutions that meet British Standards while maintaining design quality. From initial consultation through to product supply and technical support, we are here to help you achieve compliant, aesthetically appropriate emergency lighting for your commercial project. You Imagine It. We Make It Happen.
Emergency escape routes require a minimum of 1 lux at floor level across the width of the route, with a uniformity ratio no greater than 40:1. Under BS EN 1838:2024, a 0.5 m border is excluded on routes wider than 2 m, and a quarter of the width on each side on routes of 2 m or narrower. This replaces the previous centre-line method.
Maintained lighting is required where normal lighting is dimmed or off while occupied, such as cinemas and theatres. Non-maintained fittings suit workplaces like offices where occupants know the building and normal lighting illuminates escape routes. Your fire risk assessment should determine the appropriate type.
Under BS EN 50172:2024, central battery indicators should be checked daily, all systems need a monthly functional test and an annual full-duration test, typically three hours. Photometric performance must also be verified at handover and at intervals not exceeding five years. Results must be recorded in a logbook.
The 2025 revision expanded scope to cover local area lighting and standby lighting alongside emergency escape lighting. It aligns with BS EN 1838:2024 and BS EN 50172:2024, introducing full-width escape route lighting, five-year photometric verification, new recommendations for points of emphasis, toilets and lift areas, two-circuit wiring in high-risk areas, and central battery load calculations in watts and VA.
299 Lighting offers full emergency lighting design support, including spacing calculations, photometric data and compliance documentation. Our LIA-accredited engineers can review your scheme and prepare technical submissions to demonstrate compliance with British Standards.
For spaces where aesthetics matter, 299 Lighting supplies integrated emergency options for downlights, linear luminaires and suspended fittings. These allow emergency lighting to blend with your general lighting scheme rather than requiring separate, visible emergency fittings.
Our team supports architects, M&E consultants and contractors with emergency lighting design, specification and supply.
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