Which standards apply to school lighting
School lighting in England is shaped by four documents, and it helps to know which one you are being judged against:
- Workplace (Health, Safety and Welfare) Regulations 1992, regulation 8: the legal duty to provide suitable and sufficient lighting. Schools are workplaces for staff, and the same duty of care extends to pupils.
- BS EN 12464-1:2021: the indoor workplace lighting standard, which has a dedicated schedule for educational buildings. See our BS EN 12464-1:2021 guide.
- DfE guidance: Building Bulletin 90 Lighting design for schools (1999) set the original DfE approach. For DfE-funded new builds and major refurbishments it has largely been superseded by the School Output Specification, Technical Annex 2E: Daylight and Electric Lighting.
- SLL Lighting Guide 5 (LG5), Lighting for education: the CIBSE/SLL design guide for schools, colleges and universities. See the CIBSE guides index.
Classroom lux levels: 300 or 500?
This is the question we are asked most often, and the honest answer is that it depends which document you use.
DfE Output Specification: 300 lx
Technical Annex 2E sets a maintained illuminance of 300 lx for primary basic teaching areas and secondary general teaching spaces, with uniformity of 0.6 and a glare limit of UGR 19. BB90 also used 300 lx as its baseline for general teaching, with higher levels for more demanding work such as workshops and art rooms, often by adding task lighting.
BS EN 12464-1:2021: 500 lx, dimmable
The 2011 edition of BS EN 12464-1:2021 distinguished between general classrooms at 300 lx and classrooms used for evening classes and adult education at 500 lx. The 2021 edition lists classrooms at 500 lx with a requirement that lighting be controllable, so it can be dimmed for younger children and for activities that do not need full output.
What we recommend reporting against
For an existing maintained school, a classroom that achieves 300 lx with good uniformity, low glare and controllable lighting is generally defensible under the DfE criteria. For secondary schools, sixth forms, adult education and any school specifying a new installation, designing to 500 lx with dimming is the current best practice. Our reports show both benchmarks so governors and estates teams can see where they stand.
School lighting levels by space
| Space or task | Typical maintained illuminance | Notes |
|---|---|---|
| General classroom (DfE Annex 2E) | 300 lx | Uo 0.6, UGR 19 |
| Classroom (BS EN 12464-1:2021) | 500 lx | Controllable, dimmable |
| Whiteboard or chalkboard | 500 lx vertical | Uo 0.70 on the board; avoid specular reflections |
| Science labs and practical rooms | 500 lx | Higher where fine detail is involved |
| Art rooms | 500 lx | Higher, with Ra 90, in specialist art schools |
| Technical drawing | 750 lx | Local task lighting often used |
| Library reading areas | 500 lx | Bookshelves lower |
| Sports halls and gyms | 300 lx | Competition use may need more |
| Corridors and circulation | 100 lx | Stairs typically higher |
Values in the table are typical figures from BS EN 12464-1:2021 and DfE guidance. For a formal assessment we report each room against the current edition of the relevant document.
Beyond lux: what makes classroom lighting good
Uniformity
Pupils sit across the whole room, not at a few fixed desks, so the whole teaching area is effectively task area. Uniformity of at least 0.6 avoids dark corners, which are common in older classrooms where failed tubes have been left or furniture has been moved.
Glare and screens
Interactive panels, projectors and laptops make glare control critical. UGR 19 is the usual limit, and luminaires should not reflect in the board or in screens from pupils' viewing positions. Where ICT suites are used for long periods, the same principles as office DSE lighting apply.
Board lighting
Dedicated board lighting at 500 lx vertical helps pupils at the back of the room, but it must be aimed so it does not dazzle the teacher or reflect off a glossy surface.
Daylight and controls
The DfE Output Specification places heavy emphasis on daylight. Good controls, such as daylight dimming near windows and separate switching for the board and the front of the room, let teachers balance daylight, projection and electric lighting without leaving parts of the room under-lit.
SEN and visual impairment
Pupils with visual impairments, autism or sensory processing differences may be affected by flicker, glare and harsh contrast. Specialist provision often needs higher-quality, flicker-free lighting with fine dimming control.
When schools should test
- after an LED upgrade, to confirm uniformity and glare as well as lux;
- after change of use, such as converting a classroom into an ICT suite or science room;
- following complaints of headaches, eye strain or difficulty seeing the board;
- as part of a condition survey or academy transfer;
- periodically, as luminaires age; see how often testing should be carried out.
We usually survey schools in the holidays or after the school day, which also gives us the darkness needed for accurate readings of the electric lighting.
Book a school lighting survey
We carry out classroom and whole-school lux surveys for maintained schools, academies, independent schools and nurseries across London and the South East. School and nursery surveys start from £260, with the price confirmed before booking. See school lux surveys or book a survey.
Frequently asked questions
How many lux should a classroom have?
The DfE Output Specification sets 300 lx maintained for general teaching spaces, while BS EN 12464-1:2021 lists 500 lx with controllable, dimmable lighting. New installations are increasingly designed to 500 lx with dimming.
Is Building Bulletin 90 still current?
BB90 is still referenced, but for DfE-funded projects it has largely been superseded by the School Output Specification Technical Annex 2E on daylight and electric lighting.
What lux level is needed on a whiteboard?
BS EN 12464-1:2021 recommends 500 lx vertical illuminance on the board with uniformity of 0.70, and the lighting must be positioned to avoid reflections.
What is SLL LG5?
LG5 is the Society of Light and Lighting's guide to lighting for education, covering schools, colleges and universities.
How much does a school lux survey cost?
School and nursery surveys start from £260, with the final price confirmed before booking.