A new edition of BS 5266-1 Emergency lighting – Part 1: emergency lighting of premises – code of practice has been published.
NICEIC Technical Team | .
A new edition of BS 5266-1 Emergency lighting – Part 1: emergency lighting of premises – code of practice has been published. This article summarises notable changes between the 2025 edition and the 2016 edition which preceded it.
Introduction
The newly published full revision of BS 5266-1 Emergency lighting – Part 1: emergency lighting of premises – Code of practice came into effect on 31st October 2025, superseding the previous 2016 edition which is now withdrawn.
BS 5266-1 is a standard which is intended to be used in conjunction with BS EN 50172:2024 - Emergency escape lighting systems and BS EN 1838:2024 - Lighting applications – Emergency lighting for buildings, which cover the following:
Significant changes to clauses by section
Use of this document
The term ‘deviation’ has been replaced by ‘variation’ where the recommendations of the standard have intentionally not been followed due to the adoption of another technical solution or practices which provide an equivalent or better outcome to that achieved by following the recommendations of the standard.
A statement has been added clarifying that the recommendations within standard are drafted for use and implementation by appropriately qualified and experienced people (see also definition of competent person).
The copyright on Annex H (Model completion certificate), Annex I (Model certificate for completion of small new installations up to 25 self-contained luminaires), Annex K (Model certificate for verification of an existing installation) and Annex M (periodic inspection and test Model certificates) is owned by BSI. However, users of the standard are permitted to make an unlimited number of copies for their use without infringement of copyright.
It is not necessary to use the models in the annexes in order to meet the recommendations in the standard. NICEIC produce a range of certificates based on the models in BS 5266-1.
Visit www.shop.niceic.com
1 Scope
Borrowed light is now excluded from the scope. The introduction explains that this is because it cannot be relied upon a source of light.
2 Normative references
The list of normative references has been updated, with the inclusion of both BS 4422, Fire – Vocabulary, and BS 9991, Fire safety in the design, management and use of residential buildings – Code of practice.
3 Terms and definitions
The following new definitions have been added:
4 Consultation and records
Clause 4.1 - In respect of occupancy in the event of a supply failure, the term ‘”stay put” strategy’ has been replaced by where ‘occupants are likely to stay in the building’.
Note 4 now refers to a ‘place of ultimate safety’ as defined in BS 4422 (a place in which there is no immediate or future danger from fire and smoke or the effects of fire and smoke) rather than to a ‘place of safety’.
Clause 4.2 – This now states that plans of premises for use at the consultation and system design stages should also include:
Clause 5.2.2 – This now recommends additionally that local area lighting should be provided where the occupants are allowed to remain in the building during periods without normal lighting.
Clause 5.2.5 – In a defined escape route, the minimum horizontal illuminance limit on the floor of 1 lx now applies to the whole escape route floor, apart from a border the width of which is dependent on the width of the escape route, where in the previous edition it was only applicable to the centre line of the corridor.
Clause 5.2.6 – In an open area it has been clarified that, in addition to rooms having a floor area exceeding 60 m², smaller rooms which have been risk-assessed as requiring emergency lighting, must also be provided with a horizontal illuminance of at least 0.5 lx at floor level other than the border 0.5 m around the perimeter. The clause now also states that where an escape route passes through an open area, but is not clearly defined, all of the open area should be treated as an escape route and that where a defined escape route passes through the open area, emergency escape lighting should provide a minimum of 1 lx at the floor level.
Clause 5.2.8.1 g) now refers to a place of ultimate safety in relation to the placing of emergency escape lighting outside of an exit to a building. The clause also calls for emergency escape lighting:
Where, in the previous edition of the standard, this clause referred to ‘refuges’ it now refers to ‘temporary waiting spaces’.
Clause 5.2.8.5 – This now calls for a minimum horizontal illuminance of 5 lx to be provided at the baby changing table in a single occupancy toilet and at the floor in accessible toilets.
Clause 5.2.8.8 – This is a new clause for public indoor swimming pools and states a minimum horizontal illuminance of 5 lx should be provided on the water service, at floor level on circulation routes around the pool and access routes to diving boards or flumes.
7 Power supplies and equipment used as electrical sources for safety services (ESSS)
This section on power supplies now refers specifically to ‘equipment used as sources for safety services (ESSS)’. It now states that the system should be designed so that it can deliver the required power output, including any inrush or starting current, in both watts and VA, taking into account the power factor of the load. If the system is modified during its operational life, these values should be recalculated and the system records updated. This change has been introduced to address the increasing use of LED luminaires, which often have a poor power factor, particularly when modifications are made to an existing system that typically incorporate fluorescent type luminaires.
8.2 Wiring of emergency lighting luminaires supplied from a central safety power supply system
Clause 8.2.5 – The title has been changed from ‘Conduit, trunking and channel’ to ‘Cable management systems providing protection against mechanical damage’. It now recommends that where conduit or trunking is used to protect cables form mechanical damage, as opposed to being used for aesthetic purposes only, it should provide impact protection of at least 5 J.Additionally, content formerly in clause 8.2.11 in the 2016 edition relating to protection against physical damage in arduous conditions has been relocated to clause 8.2.5.
Clause 8.2.7 – The title has been changed for ‘cable sizes’ to ‘cross-sectional area of conductors’. It now states that the cross-sectional area of conductors should be sized in accordance with BS 7671.
Clause 8.2.8 – The title has been changed from ‘overhead lines’ to ‘suspended cables’.
Clause 8.2.9 - This clause relates to damp, corrosive or underground locations. Again, it is now stated that the cross-sectional area of conductors should be sized in accordance with BS 7671.
Clause 8.2.10 – This clause now recommends that cables should not be installed in any location, such as a boiler room, where the combination of ambient temperature and temperature rise due to load currents will result in their rated temperature being exceeded.
Clause 8.2.12 - This clause contains the recommendations for voltage compatibility of a centrally supplied emergency luminaire and a central battery system which were in clause 8.3.5 of the previous edition.
Clause 8.2.13 – This clause has been expanded and now contains the recommendations for electromagnetic compatibility which were in clause 8.4 of the previous edition.
Clause 8.2.14 – This is a new clause giving recommendations for the identification of cables (based on emergency lighting luminaires supplied from a central safety power supply system only)
All cables supplying emergency lighting luminaires should either be identified:
a) by a single, common unique colour in case of multicore cables; or
b) at every connection between conductors and between a conductor and equipment, such that they are distinguished from those of other circuits, by labelling.
Section 10 Emergency lighting design procedure
Clause 10.2 – In this clause (Determine requirements) a new note has been added to indent k) calling for emergency illumination within the main switch room only, that is, unless it is identified by the risk assessment that such emergency lighting is required at the location of sub-distribution boards. Additionally, a new indent m) has been added calling for the position of the emergency lighting of any public indoor swimming pools to be identified.
Clause 10.4 – In this clause (Design of system) a new indent m) has been added recommending that the procedures to protect a system (e.g. battery from deep discharge) in case they are shut down for prolonged periods and the procedure to recommission the system after the shut-down period are checked. A new note 1 has also been added stating that ‘any prolonged period of over discharge can be harmful depending on the battery type.’
11 Certificates and logbook
Clause 11.1 – The following new recommendations have been added:
12 Routine inspection and tests
Section 12 – New text has been added in this clause which covers routine inspections and tests, reiterating that the photometric performance of the system should be verified at intervals not exceeding five years.
Summary
This article has introduced notable changes introduced in the new edition of BS 5266-1 which was published on the 31st October 2025. However, this does not mean that all such changes have been identified here. As a result, readers working with emergency lighting systems covered by BS 5266-1, BS EN 50172:2024 and BS EN 1838:2024 are advised to familiarise themselves with the content of these three standards, which have all been updated in the last two years.
Certsure produces a full range of certificates for emergency lighting systems for use by certified businesses.
Introduction
The newly published full revision of BS 5266-1 Emergency lighting – Part 1: emergency lighting of premises – Code of practice came into effect on 31st October 2025, superseding the previous 2016 edition which is now withdrawn.
BS 5266-1 is a standard which is intended to be used in conjunction with BS EN 50172:2024 - Emergency escape lighting systems and BS EN 1838:2024 - Lighting applications – Emergency lighting for buildings, which cover the following:
- general requirements for emergency escape lighting;
- escape route lighting;
- open area (anti-panic) lighting;
- high-risk task area lighting;
- local area lighting; and
- in BS EN 1838 only, standby lighting.
Significant changes to clauses by section
Use of this document
The term ‘deviation’ has been replaced by ‘variation’ where the recommendations of the standard have intentionally not been followed due to the adoption of another technical solution or practices which provide an equivalent or better outcome to that achieved by following the recommendations of the standard.
A statement has been added clarifying that the recommendations within standard are drafted for use and implementation by appropriately qualified and experienced people (see also definition of competent person).
The copyright on Annex H (Model completion certificate), Annex I (Model certificate for completion of small new installations up to 25 self-contained luminaires), Annex K (Model certificate for verification of an existing installation) and Annex M (periodic inspection and test Model certificates) is owned by BSI. However, users of the standard are permitted to make an unlimited number of copies for their use without infringement of copyright.
It is not necessary to use the models in the annexes in order to meet the recommendations in the standard. NICEIC produce a range of certificates based on the models in BS 5266-1.
Visit www.shop.niceic.com
1 Scope
Borrowed light is now excluded from the scope. The introduction explains that this is because it cannot be relied upon a source of light.
2 Normative references
The list of normative references has been updated, with the inclusion of both BS 4422, Fire – Vocabulary, and BS 9991, Fire safety in the design, management and use of residential buildings – Code of practice.
3 Terms and definitions
The following new definitions have been added:
- activation time (of an emergency lighting system)
- automatic test system
- electrical source for safety services (ESSS)
- emergency local area lighting (this was previously emergency safety lighting)
- fixed seating
- system duration (of an emergency lighting system)
- escape route
- final exit
- material times
- open area lighting
- place of safety
4 Consultation and records
Clause 4.1 - In respect of occupancy in the event of a supply failure, the term ‘”stay put” strategy’ has been replaced by where ‘occupants are likely to stay in the building’.
Note 4 now refers to a ‘place of ultimate safety’ as defined in BS 4422 (a place in which there is no immediate or future danger from fire and smoke or the effects of fire and smoke) rather than to a ‘place of safety’.
Clause 4.2 – This now states that plans of premises for use at the consultation and system design stages should also include:
- escape route signs
- special locations (see clause 5.2.8.1 of BS 5266-1)
Clause 5.2.2 – This now recommends additionally that local area lighting should be provided where the occupants are allowed to remain in the building during periods without normal lighting.
Clause 5.2.5 – In a defined escape route, the minimum horizontal illuminance limit on the floor of 1 lx now applies to the whole escape route floor, apart from a border the width of which is dependent on the width of the escape route, where in the previous edition it was only applicable to the centre line of the corridor.
Clause 5.2.6 – In an open area it has been clarified that, in addition to rooms having a floor area exceeding 60 m², smaller rooms which have been risk-assessed as requiring emergency lighting, must also be provided with a horizontal illuminance of at least 0.5 lx at floor level other than the border 0.5 m around the perimeter. The clause now also states that where an escape route passes through an open area, but is not clearly defined, all of the open area should be treated as an escape route and that where a defined escape route passes through the open area, emergency escape lighting should provide a minimum of 1 lx at the floor level.
Clause 5.2.8.1 g) now refers to a place of ultimate safety in relation to the placing of emergency escape lighting outside of an exit to a building. The clause also calls for emergency escape lighting:
- at the point where an alarm call is received from a passenger lift car and associate lift winding equipment
- Corridors from passenger lift doors to the nearest escape route.
Where, in the previous edition of the standard, this clause referred to ‘refuges’ it now refers to ‘temporary waiting spaces’.
Clause 5.2.8.5 – This now calls for a minimum horizontal illuminance of 5 lx to be provided at the baby changing table in a single occupancy toilet and at the floor in accessible toilets.
Clause 5.2.8.8 – This is a new clause for public indoor swimming pools and states a minimum horizontal illuminance of 5 lx should be provided on the water service, at floor level on circulation routes around the pool and access routes to diving boards or flumes.
7 Power supplies and equipment used as electrical sources for safety services (ESSS)
This section on power supplies now refers specifically to ‘equipment used as sources for safety services (ESSS)’. It now states that the system should be designed so that it can deliver the required power output, including any inrush or starting current, in both watts and VA, taking into account the power factor of the load. If the system is modified during its operational life, these values should be recalculated and the system records updated. This change has been introduced to address the increasing use of LED luminaires, which often have a poor power factor, particularly when modifications are made to an existing system that typically incorporate fluorescent type luminaires.
8.2 Wiring of emergency lighting luminaires supplied from a central safety power supply system
Clause 8.2.5 – The title has been changed from ‘Conduit, trunking and channel’ to ‘Cable management systems providing protection against mechanical damage’. It now recommends that where conduit or trunking is used to protect cables form mechanical damage, as opposed to being used for aesthetic purposes only, it should provide impact protection of at least 5 J.Additionally, content formerly in clause 8.2.11 in the 2016 edition relating to protection against physical damage in arduous conditions has been relocated to clause 8.2.5.
Clause 8.2.7 – The title has been changed for ‘cable sizes’ to ‘cross-sectional area of conductors’. It now states that the cross-sectional area of conductors should be sized in accordance with BS 7671.
Clause 8.2.8 – The title has been changed from ‘overhead lines’ to ‘suspended cables’.
Clause 8.2.9 - This clause relates to damp, corrosive or underground locations. Again, it is now stated that the cross-sectional area of conductors should be sized in accordance with BS 7671.
Clause 8.2.10 – This clause now recommends that cables should not be installed in any location, such as a boiler room, where the combination of ambient temperature and temperature rise due to load currents will result in their rated temperature being exceeded.
Clause 8.2.12 - This clause contains the recommendations for voltage compatibility of a centrally supplied emergency luminaire and a central battery system which were in clause 8.3.5 of the previous edition.
Clause 8.2.13 – This clause has been expanded and now contains the recommendations for electromagnetic compatibility which were in clause 8.4 of the previous edition.
Clause 8.2.14 – This is a new clause giving recommendations for the identification of cables (based on emergency lighting luminaires supplied from a central safety power supply system only)
All cables supplying emergency lighting luminaires should either be identified:
a) by a single, common unique colour in case of multicore cables; or
b) at every connection between conductors and between a conductor and equipment, such that they are distinguished from those of other circuits, by labelling.
Section 10 Emergency lighting design procedure
Clause 10.2 – In this clause (Determine requirements) a new note has been added to indent k) calling for emergency illumination within the main switch room only, that is, unless it is identified by the risk assessment that such emergency lighting is required at the location of sub-distribution boards. Additionally, a new indent m) has been added calling for the position of the emergency lighting of any public indoor swimming pools to be identified.
Clause 10.4 – In this clause (Design of system) a new indent m) has been added recommending that the procedures to protect a system (e.g. battery from deep discharge) in case they are shut down for prolonged periods and the procedure to recommission the system after the shut-down period are checked. A new note 1 has also been added stating that ‘any prolonged period of over discharge can be harmful depending on the battery type.’
11 Certificates and logbook
Clause 11.1 – The following new recommendations have been added:
- the results of the commissioning inspections and tests defined in BS EN 50172:2024 should be included in the handover documents described in clause 10.7.1.
- Any variations from BS 5266-1 within a specification or design proposal should be so identified that they are obvious to any interested party that is responsible for its approval and should be documented in the handover documentation.
12 Routine inspection and tests
Section 12 – New text has been added in this clause which covers routine inspections and tests, reiterating that the photometric performance of the system should be verified at intervals not exceeding five years.
Summary
This article has introduced notable changes introduced in the new edition of BS 5266-1 which was published on the 31st October 2025. However, this does not mean that all such changes have been identified here. As a result, readers working with emergency lighting systems covered by BS 5266-1, BS EN 50172:2024 and BS EN 1838:2024 are advised to familiarise themselves with the content of these three standards, which have all been updated in the last two years.
Certsure produces a full range of certificates for emergency lighting systems for use by certified businesses.
