Get in touch with us
On this page:

    Revit Guides

    Data Management

    ELI5

    BS 5266‑1:2025 - whats changed?

    Status & scope. The new edition was published on 29th and came into effect on 31 October 2025, withdrawing BS 5266-1:2016. It is intended to be read with BS EN 50172:2024 (emergency escape lighting systems) and BS EN 1838:2024 (performance requirements).

    Terminology & concepts. BS 5266‑1:2025 adopts the term “emergency local area lighting” and provides an updated definition; the earlier “emergency safety lighting” term used in 2016 is not used in the 2025 edition.
    Design. The 2025 edition explicitly states that borrowed light is not included in the standard and defines it as light from any source other than the building’s emergency lighting. Do not rely on “borrowed light” to meet emergency lighting requirements. And New central‑system wiring rules (e.g., max 20 luminaires per final‑circuit fault and two separate circuits for high‑risk task areas). 

    5‑year photometric verification (required by BS 5266‑1:2025; aligned with EN 50172:2024),

    Competence. The 2025 definitions clarify that a “competent person” can include organisations.

    Standards at a glance

    • BS 5266‑1:2025 (Code of practice – Emergency lighting of premises) — overarching code.

    • BS EN 1838:2024 (Lighting applications – Emergency lighting for buildings).

    • BS EN 50172:2024 (Emergency escape lighting systems).

    • BS EN IEC 60598‑2‑22:2022 (emergency luminaires).

    • BS EN 50171:2021 (central safety power supply systems).

    • BS EN ISO 7010:2020+A8:2024 and BS 5499‑10:2014+A1:2023 (safety signs, viewing distances).

    • BS 7671:2018+A3:2024 (IET Wiring Regulations).

    • BS EN IEC 62485‑5 (stationary Li‑ion battery safety – if you discuss battery rooms).

    Performance compliance

    BS 5266‑1:2025 refers to BS EN 1838:2024 for lighting performance and states minimum requirements:

    • Escape routes: ≥ 1 lx across the whole route width. For routes > 2 m, exclude 0.5 m borders; for routes ≤ 2 m, exclude border zones equal to one‑quarter of the width. (This is the major shift away from centre‑line only.)

    • Open areas (anti‑panic): ≥ 0.5 lx at floor level (areas ≥ 60 m²).

    • High‑risk task areas: ≥ 10 % of the average normal lighting and not less than 15 lx; response time ≤ 0.5 s.

    • Points of emphasis: provide ≥ 5 lx vertical at call points, first‑aid points, firefighting equipment, and safety controls/signage.

    Informative examples from BS 5266‑1:2016 Annex E: typical values such as treatment rooms 50 lx, first‑aid rooms 15 lx, or reception 15 lx – these have not changed.

    Understanding the Dual-Standard Approach: BS EN 1838:2024 vs BS 5266-1:2025

    UK emergency lighting compliance requires understanding two complementary but distinct standards that work together to ensure building safety. For designers seeking to provide compliant systems, it’s crucial to understand when and how to apply each standard.

    BS EN 1838:2024: The Performance Standard

    Purpose: Specifies the luminous requirements (what lighting levels must be achieved) for emergency escape lighting and standby lighting systems. This is a European performance standard that defines technical lighting targets.[1]

    When to Use: BS EN 1838:2024 is referenced when determining:

    • Required illuminance levels for different areas

    • Measurement procedures and verification of lighting performance

    • Technical specifications for adaptive emergency escape lighting systems (AEELS)[2]

    • Compliance with European harmonised standards

    Key 2024 Updates:

    • Full Width Route Illumination: Escape routes now require illumination across the entire route width, not just the centre line. For routes wider than 2m, exclude 0.5m borders; for routes 2m or narrower, exclude quarter-width borders[3]

    • Enhanced Points of Emphasis: Minimum 5 lx vertical at points of emphasis (maintained in the latest editions and restated in BS 5266‑1:2025).

    • Adaptive Emergency Escape Lighting Systems (AEELS): New requirements for intelligent systems that can modify escape routes based on real-time conditions[5]

    • Local Area Lighting: Specific provisions for occupants remaining in buildings during power outages[6]

    BS 5266-1:2025 The Code of Practice

    Purpose: Provides comprehensive practical guidance for design, installation, commissioning, testing, and maintenance of emergency lighting systems. This is the UK’s complete application standard.

    When to Use: BS 5266-1:2025 is essential for:

    • System design and layout planning

    • Installation procedures and wiring requirements

    • Commissioning checklists and handover procedures

    • Testing protocols and maintenance schedules

    • Risk assessment guidance

    • Record keeping and documentation

    Scope: Covers the complete project lifecycle from initial consultation through ongoing maintenance, with specific guidance for diverse UK building types.

    Which standard do I use when?

    Design StageUse BS EN 1838:2024 ForUse BS 5266-1:2025 For
    Performance SpecificationLight levels, illuminance targets, measurement criteria, points of emphasis.System classification, duration requirements, design procedures
    Layout DesignFull-width route illumination requirements, points of emphasisLuminaire spacing, positioning, coverage areas
    System SelectionAEELS requirements, technical performancePower supply selection, wiring methods, system types
    InstallationMeasurement verification proceduresInstallation methods, cable requirements, commissioning
    Compliance VerificationIlluminance testing and measurementTesting schedules, documentation, certification

    Refresh your terminology

    “Emergency safety lighting” ➜ “Emergency local area lighting” keep the 1 lx minimum for movement areas (unchanged in practice).

    “part of emergency lighting that provides illumination for people allowed to remain temporarily in a premises during a mains supply failure if it is risk assessed for the activities that are allowed to be performed.” BS 5266-1:2025, 3 Terms and definitions – 3.9

    Adaptive Emergency Escape Lighting Systems (AEELS)

    Adaptive emergency escape lighting (AEEL/AEELS): EN 1838:2024 recognises adaptive systems, and CEN/TS 17951:2024 provides detailed application guidance. Adoption is risk- and project-specific, not universal; where deployed, systems must still achieve EN 1838 performance and revert to a safe fallback if controls fail. [BS EN 1838:2024 – TC]

    Design & wiring (what changed and what stays the same)

    Central battery systems: 

    “Design so that a single final‑circuit fault affects no more than 20 emergency luminaires; supply high‑risk task areas from at least two separate circuits; route emergency circuits through areas of low fire risk; support wiring to prevent premature collapse in accordance with BS 7671.”

    Self‑contained luminaires (non‑central):
    BS 5266‑1:2025 confirms that self‑contained luminaires do not require fire‑protected supply cables; wire them to the same standard as normal lighting circuits and in accordance with BS EN 50172:2024 and BS 7671.

    Centrally supplied systems (central battery / static inverter / generator):
    Clause 8.2 makes explicit several rules that designers often apply by practice:

    • Circuit survival & routing: Use cable/cable systems that resist fire and mechanical damage and retain circuit integrity; route through areas of low fire risk wherever practicable; protective measures against foreseeable mechanical damage are required.

    • Limit single‑fault impact: No more than 20 emergency luminaires are to be affected by a single fault on a final circuit.

    • High‑risk areas: Wire alternately or from at least two separate circuits so some illuminance is maintained if one circuit fails.

    • Product standards: Luminaires to BS EN IEC 60598‑2‑22:2022; central power supplies to BS EN 50171:2021; downstream protective device selection and use per BS EN 50172:2024.

    Cable survival times (central systems).
    BS 5266‑1:2025 keeps the risk‑based approach and refers to cable/application standards.

    In practice, designers select survival times by scenario using BS 8519 categories: Category 2 = 60 min, Category 3 = 120 min.

    BS 8519 Table 1 lists “Emergency lighting – central battery and distribution” with minimum Category 2, with higher categories where the fire strategy demands it.

    Practical rule‑of‑thumb (evidence‑based):

    • Standard centrally‑supplied escape lighting: Category 2 (~60 min).

    • Enhanced survival (e.g., phased evacuation in unsprinklered buildings or unsprinklered buildings > 30 m): Category 3 (~120 min). BS 5266‑1:2016 carried explicit examples for high‑rise unsprinklered contexts; the 2025 edition embeds the risk‑based selection and the 60/120‑minute landscape via cross‑references.

    BS 7671 interface (safety services).
    Keep wiring independent of other circuits (Section 560), provide appropriate fault/short‑circuit protection, and ensure supports/prevention of premature collapse in line with BS 7671 (including Amendment 3:2024 updates).

    UK Building Regulations Compliance Framework

    Legal Requirements:

      • Regulatory Reform (Fire Safety) Order 2005 (Article 14(h)) – emergency routes/exits requiring illumination must have emergency lighting of adequate intensity when normal lighting fails. [Legislation.gov.uk]

      • Approved Document B (Vols 1 & 2) – statutory guidance signposting emergency lighting provisions and definitions. [GOV.UK]

      • Safety Signs and Signals Regs 1996 – powered signs must have a guaranteed emergency supply if hazards persist. [Legislation.gov.uk] 

    Standards Hierarchy:

    1. BS EN 1838:2024: Technical performance requirements (European harmonised)

    2. BS 5266-1:2025: UK code of practice and application guidance

    3. BS EN 50172:2024: Testing and maintenance procedures[18]

    4. BS EN 60598-2-22:2022: Luminaire safety and performance standards[18]

    For UK Compliance: Projects must satisfy both the technical performance targets of BS EN 1838:2024 and the practical application requirements of BS 5266-1:2025.

    Luminaire Performance Requirements under BS EN 60598-2-22:2020/2021

    The standard BS EN 60598-2-22 has undergone significant updates, with the latest version being IEC 60598-2-22:2021 (adopted as BS EN 60598-2-22:2022) [19][20][21]. The key performance changes include:

    Updated Requirements [22]:

    • Rest mode and inhibiting mode requirements have been updated and clarified

    • High-temperature operation tests have been clarified with more specific testing procedures

    • New requirements for lithium batteries have been introduced to address modern battery technologies

    • Electric double layer capacitors (EDLCs) now have specific requirements

    • Resistance to heat, fire and tracking requirements have been clarified

    • Test facilities for self-contained luminaires have been clarified

    • Contrast measurements for exit signs test methods have been improved

    The luminaires must comply with these performance standards to ensure reliable operation during emergency conditions[23][24]. See EN IEC 60598‑2‑22:2022 change list (rest/inhibit, lithium, EDLC, high‑temperature tests, sign contrast).” [ANSI Webstore]

    Changes to Emergency Lighting Maintenance and Testing

    Recent updates to maintenance and testing requirements have introduced more stringent procedures:

    BS EN 50172:2024 inspection/testing overview: The standard retains daily (visual indicators – central systems), monthly (functional), annual (full duration) and adds a five‑year verification step; also strengthens handover, logbook and maintenance guidance. [ANSI]

    BS 5266-1:2025 Updates :

    • Photometric verification: initially and then at intervals not exceeding 5 years (BS 5266‑1:2025, as per EN 50172:2024).

    • Routine tests (unchanged cadence, clarified wording): monthly functional; annual full‑duration, with the cautions about reduced protection while batteries recharge and “test at low‑risk times or alternate luminaires.” Reference your logbook to capture results.

    • Handover & records: include EN 50172:2024 commissioning test results in the handover pack, and update logbook contents (e.g., responsible persons, maintenance arrangements).

    Testing Frequencies [28][29][30]:

    • Daily tests: Only required for central battery systems

    • Monthly functional tests: Brief 30-second to 1-minute tests to verify operation [28][29]

    • Annual duration tests: Full 3-hour discharge tests to verify battery capacity [28][29]

    • Bi-annual inspections: New requirement to check for damage, dirt, dust, and material degradation

    Fire-Resisting Cable and Circuit Routing Requirements

    Emergency lighting cables must meet enhanced fire protection requirements [30][31]:

    Cable Performance Standards:

    • PH60/PH120 does not apply to all emergency lighting wiring. BS 5266‑1 makes a clear distinction: self‑contained emergency luminaires do not require fire‑protected supply cables (so PH‑class cable is not required for the supply to the fitting).
    • Centrally supplied systems (central battery/static inverter) and generators used for emergency escape/local‑area lighting do require fire-resistant cabling with defined survival times.
    • For centrally supplied systems, select cables to achieve at least PH60 (typical – baseline) or PH120 (enhanced) survival when tested to BS EN 50200/BS 8434‑2, as appropriate to the design.
    • PH120 (enhanced) is recommended where the risk justifies longer circuit survival, such as phased evacuation in unsprinklered buildings, unsprinklered buildings > 30 m, or where a fire remote from the cables could still compromise occupied areas.
    • Provide segregation and fire‑resistant supports; fixings must prevent premature collapse in line with BS 7671.

    Installation Requirements [32] [33]:

    • Fire-resisting supports are required for wiring systems in escape routes under BS 7671 Regulation 521.11.201 [32]

    • Segregation requirements when emergency lighting cables share containment with other services [31]

    • Non-combustible support methods are required – plastic clips, ties, or trunking cannot be the primary means of support [31]

    • Cables must be exclusive to the emergency lighting installation and separate from other circuits [31]

    Circuit Protection [34] [35]:

    • Emergency system wiring must be entirely independent of all other wiring, with limited exceptions [34] [35]

    • Two-hour fire protection is required for specific installations in assembly occupancies or buildings above > 30 m (example in BS 5266‑1) – recommendations arising from risk and evacuation strategy (e.g., phased evacuation, unsprinklered/complex buildings).

    • Listed fire-rated assemblies or electrical circuit protective systems may be required

    Updates from BSI and Emergency Signage

    BS 9991:2024 Updates [36] [37] [38]:
    The revised BS 9991:2024 (Fire safety in residential buildings) was published on November 27, 2024, introducing:

    • Expanded scope to include residential care homes

    • Enhanced guidelines for evacuation lifts

    • Revised height limits for sprinkler installation and single-stair buildings

    • European classifications for fire doors

    • Smoke control enhancements

    BS EN 1838:2024 Updates [39] [40]:
    The new emergency lighting standard, published December 31, 2024, includes:

    • Revised escape route lighting requirements to cover the entire route width

    • Adaptive Emergency Escape Lighting Systems (AEELS) recommendations for all building types

    • Enhanced specifications for points of emphasis and hazardous areas

    • 5 lux minimum vertically at fire alarm call points and firefighting equipment

    PLS (Photoluminescent Safety) Location Criteria

    Photoluminescent safety systems are governed by the following standards [31] [32] [33]:

    Key Standards:

    • BS 5266‑1/EN 1838 for sign illumination/visibility.
    • BS EN ISO 7010:2020+A8:2024: International standard for safety symbols 

    • UL 924: Standard for Emergency Lighting and Power Equipment [35] [33]

    Installation Requirements [32] [33]:

    • Minimum 5 foot-candles of ambient illumination on photoluminescent signs [36]

    • Continuous illumination required while buildings are occupied [33]

      • Charging illumination must be from reliable light sources as determined by authorities [33]

    CIBSE Updates

    The CIBSE LG12 Emergency Lighting (2022) edition [37] [38] provides updated guidance emphasising:

    • Risk assessment-based approaches to emergency lighting design

    • Standardised terminology from BSI definitions

    • Enhanced design management procedures

    • Compliance documentation requirements for safety legislation

    • Updated equipment and system guidance

    This guide reflects the evolution from prescriptive rules to risk-based design approaches, ensuring emergency lighting systems are optimised for specific building circumstances while maintaining full compliance with safety legislation [37] [39].

    Designer's Compliance Checklist

    Pre-Design Phase:

    • Confirm scope & risks. Identify escape routes, open areas, points of emphasis, and any high‑risk tasks.

    • Set performance to EN 1838 targets; apply the full‑width 1 lx rule on routes and 0.5 lx open‑area minima.

    • Choose system type. Self‑contained vs centrally supplied; if central, select cable survival (e.g., Category 2 ≈ 60 min as a baseline; Category 3 ≈ 120 min where your fire strategy justifies enhanced integrity).

    Design Phase:

    • Lay out circuits to limit any single‑fault to ≤ 20 luminaires and split high‑risk areas across ≥ 2 circuits.

    • Install to BS 7671 and maintain independence of safety services circuits; avoid premature collapse of wiring/supports.

    Installation Phase:

      • Use BS 5266-1:2025 installation guidance
      • Use fire-resistant cabling per requirements

     

    Handover Phase:

    • Verify illuminance levels per BS EN 1838:2024
    • Commission & hand over the logbook, declarations, drawings, and initial verification results; plan ≤ 5‑year photometric verification.

    Two-Hour Fire Protection Requirement

    The requirement for two-hour fire protection in emergency lighting and associated circuits is a key safety measure in high-risk environments. This is primarily applied to:

    • Assembly occupancies (buildings used for gathering people, such as theatres, halls, large restaurants)

    • Buildings > 30 m (example in BS 5266‑1)”

    Recommendations arising from risk and evacuation strategy (e.g., phased evacuation, unsprinklered/complex buildings).

    Why Two-Hour Fire Protection?

    • Purpose: To ensure emergency systems—especially escape lighting, alarms, and evacuation controls—remain operational long enough for safe evacuation, even under severe fire conditions.

    • Evacuation Complexity: High-rise buildings and assembly spaces may require staged or delayed evacuations, necessitating longer circuit integrity.

    • Regulatory Basis: This minimum is reflected in British Standards such as BS 5266-1 (emergency lighting) and referenced in wiring regulations and circuit design practice for life safety systems [51] [52] [53].

    Where Two-Hour Fire-Rated Circuits Are Required

    • Emergency lighting circuits in large assembly spaces and buildings over 23 metres

    • Fire alarm cabling and control circuits for critical fire safety systems

    • Evacuation lift supplies, smoke control, and firefighting equipment circuits in high-rise or assembly buildings

    Fire resistance must be ensured either by:

    • Cables with at least 120 minutes (PH120) fire resistance (tested typically at 830°C, complying with BS EN 50200/BS8434-2 or BS 8519 for control circuits)

    • Or installation within a fire-resisting enclosure, fire-protected shaft, or concrete encasement giving minimum two-hour protection [52] [53] [54] [55]

     

    Methods of Achieving Two-Hour Protection

    Solution TypeExamples & Notes
    Fire-resistant cableEnhanced fire-resistant cables (PH120) such as those complying with BS 7629-1, BS 8491, or BS 8434-2
    Mineral-insulated (MI)MI cables listed as fire-resistive, typically with 2-hour rating
    Protected containmentInstallation in fire-protected shafts, ductwork, or concrete encasement with 2-hour fire rating
    Listed assembliesSpecially tested assemblies or trays with documented 2-hour circuit integrity

    Regulatory Guidance

    • As per BS 5266 and related commentary, the application of two-hour-rated cable or protection is required in:

      • Assembly occupancies where evacuation is complex, phased, or where large numbers delay escape

      • High-rise (typically above 23m/75 ft) buildings, to allow for delayed or progressive evacuation

    • Enhanced fire resistance (two hours) is also recommended where evacuation cannot be immediate or is undertaken in stages [52] [53] [54].

    Summary Table: Circuit Fire Protection for Emergency Systems

    Installation ScenarioMinimum Circuit Fire Rating
    Standard buildings (normal risk)1 hour (PH60) inside escape routes
    Assembly occupancy/high-rise (>23m)2 hours (PH120) throughout circuit
    Unsprinklered, complex evacuation2 hours (PH120), enhanced specification

    Practical Application Examples

    Example 1: Office Building Corridor (3m wide)

    • BS EN 1838:2024: Requires 1 lux across full 2m central band (excluding 0.5m borders)

    • BS 5266-1:2025: Provides luminaire spacing and mounting guidance for achieving this requirement

    Example 2: High-Risk Manufacturing Area

    • BS EN 1838:2024: Specifies minimum illuminance levels for safe shutdown procedures

    • BS 5266-1:2025: Details installation methods for harsh industrial environments

    Example 3: Large Assembly Hall with AEELS

    • BS EN 1838:2024: Defines AEELS performance requirements and fallback provisions

    • BS 5266-1:2025: Provides system design methodology and integration guidance

    Summary for UK Designers

    Key Takeaways:

    1. Both standards are required for UK compliance – they are complementary, not alternatives

    2. BS EN 1838:2024 defines “what” (performance targets) while BS 5266-1:2025 defines “how” (practical implementation)

    3. Full-width route illumination is now mandatory – update existing design practices

    4. AEELS consideration is required for all new projects

    5. Enhanced documentation requirements under updated testing standards

    For Immediate Implementation:

    • Update design templates to reflect full-width illumination requirements

    • Include AEELS assessment in project specifications

    • Ensure measurement verification procedures align with BS EN 1838:2024

    • Apply BS 5266‑1:2025 design and installation practices (2016 withdrawn).

    Related Standards:

    • BS 5266-1:2016: Emergency Lighting Code of Practice

    • BS EN 1838:2024: Lighting Applications – Emergency Lighting

    • BS EN 50172:2024: Testing and Maintenance

    • BS 8519: Fire-resistant Cable Systems

    • BS EN 50200, BS 8434-2: Fire Testing of Cables

    • UK Building Regulations, Section B for Fire Safety

    On This page

      Leave a Reply

      Your email address will not be published. Required fields are marked *

      share this page