CIBSE, the SLL and why their guides matter
The Society of Light and Lighting (SLL) is the lighting arm of the Chartered Institution of Building Services Engineers (CIBSE). It publishes the main UK design guidance for lighting: the SLL Code for Lighting, the SLL Lighting Handbook and a numbered series of Lighting Guides (LG) for specific building types and topics. None of these is law, but they are what consulting engineers design to, what specifications cite, and what an expert witness will refer to when lighting is disputed.
The guides work alongside BS EN 12464-1:2021, not instead of it. The standard sets the headline task values; the Lighting Guides explain how to apply them in a particular kind of building, add UK-specific advice, and fill gaps the standard does not cover in detail, such as night lighting on hospital wards or lighting for stairs.
The SLL Code for Lighting
The SLL Code for Lighting (current edition 2022) is the core reference. It sets out lighting criteria and recommendations for a wide range of indoor and outdoor applications, generally aligned with the BS EN 12464 series, and covers illuminance, uniformity, glare, colour, daylight, controls and maintenance. If a building type does not have its own Lighting Guide, the Code is the starting point. The SLL Lighting Handbook (2018) is the companion volume, explaining the theory and design methods behind the recommendations.
Index of SLL Lighting Guides
The table below lists the current Lighting Guides and when each is the relevant reference. Some guides have been revised several times; always check you are using the latest edition from CIBSE.
| Guide | Title | When it applies |
|---|---|---|
| LG0 | Introduction to light and lighting | Primer for non-specialists and facilities teams |
| LG1 | The industrial environment | Factories, production, processing and distribution areas (not offices within them) |
| LG2 | Lighting for healthcare premises | Hospitals, clinics, GP surgeries and other healthcare buildings |
| LG4 | Sports lighting | Sports halls, pitches, courts and leisure centres |
| LG5 | Lighting for education | Schools, colleges and universities |
| LG6 | The exterior environment | External areas, building surrounds, car parks and obtrusive light |
| LG7 | Offices | Offices, including screen-based work, meeting rooms and home offices |
| LG8 | Lighting for museums and art galleries | Display lighting and conservation of sensitive objects |
| LG9 | Lighting for communal residential buildings | Flats, HMOs, student accommodation, sheltered housing and care homes |
| LG10 | Daylighting: a guide for designers | Daylight design in any building type |
| LG11 | Surface reflectance and colour | Choosing finishes and their effect on lighting |
| LG12 | Emergency lighting | Escape route, open area and high-risk task emergency lighting design |
| LG13 | Lighting for places of worship | Churches, mosques, temples and similar buildings |
| LG14 | Control of electric lighting | Presence detection, daylight dimming and networked controls |
| LG15 | Transport buildings | Stations, airports and interchanges |
| LG16 | Lighting for stairs | Stairs and level changes in any building |
| LG17 | Retail premises | Shops, supermarkets and shopping centres |
| LG18 | Licensed premises | Pubs, bars, restaurants and venues |
| LG19 | Extreme conditions | Hazardous, wet, hot, cold or dirty environments |
| LG20 | Facilities management | Operating, maintaining and upgrading lighting in use |
| LG21 | Protecting the night-time environment | Limiting obtrusive light and sky glow |
| LG22 | Lighting for control rooms | Control rooms and operations centres |
There is currently no LG3. The old guide to lighting for display screen use was withdrawn, and screen-based work is now dealt with in LG7.
The guides you are most likely to need
LG7: offices
LG7 (2023) aligns its recommendations with BS EN 12464-1:2021, including 500 lx for general office tasks and the use of context modifiers to raise or lower levels. It shifts the focus from a single working plane to the task area, and adds guidance on hybrid working, home offices, embodied carbon and reuse of luminaires. See office lighting standards.
LG5: education
LG5 covers classrooms, practical rooms, sports halls and lecture theatres. For DfE-funded schools it is read alongside the DfE Output Specification, which sets its own lighting criteria. See school and classroom lighting.
LG1: industrial
LG1 covers production, treatment, manufacture and distribution of products, including warehouses and storage. It gives guidance industry by industry and on issues such as high-bay lighting and stroboscopic effects. See warehouse lighting standards.
LG2: healthcare
LG2 (2019) covers lighting for clinical and non-clinical areas, including multiple lighting scenes in bedded areas for general care, examination, reading, watch and night lighting. See healthcare lighting requirements.
LG9 and LG12: residential and emergency
LG9 is the reference for common parts of flats, HMOs and care homes, where landlords have duties for stairs and corridors. LG12 complements BS 5266-1:2025 and BS EN 1838:2024 for emergency lighting design.
How the guides are used in a lux survey
A lux survey measures what is actually installed. The guides tell us what the results should be compared with and how to interpret them. For a mixed-use building we pick the relevant guide for each area, for example LG7 for office floors, LG16 for stairs, LG1 for the warehouse and LG6 for the yard, and report each against the corresponding BS EN 12464 values. Where a guide recommends something the standard does not, such as night lighting levels in healthcare, we report against the guide and say so.
This matters when results are borderline. A corridor that meets the minimum in HSG38 may still fall short of the guide's recommendation, and the report should make that distinction clear so you can decide what to prioritise.
Book a survey reported against the right guide
We carry out lux surveys across London and the South East and report each space against the appropriate SLL guide and BS EN 12464 values, so you are not left interpreting raw numbers. Book a survey.
Frequently asked questions
Are CIBSE lighting guides a legal requirement?
No. They are industry design guidance published by the Society of Light and Lighting. They are widely cited in specifications and are used as evidence of good practice when lighting is disputed.
What is the SLL Code for Lighting?
It is the Society of Light and Lighting's core reference document setting out lighting criteria for a wide range of applications. The current edition is 2022 and it is generally aligned with the BS EN 12464 series.
Which CIBSE guide covers offices?
LG7, Offices. The 2023 edition aligns with BS EN 12464-1:2021 and adds guidance on hybrid working, home offices and the energy and carbon impact of lighting.
What happened to LG3?
LG3 covered lighting for display screen use and has been withdrawn. Lighting for screen-based work is now covered within LG7.