Office Lighting Compliance: The Definitive Guide
Ensuring your workspace meets UK regulations is about more than just avoiding fines. It’s about visual comfort, productivity, and safety. Here is everything you need to know about Lux levels, UGR, and LG7.
Why Compliance Matters
In the UK, office lighting is governed primarily by the Health and Safety at Work Act 1974 and specifically detailed in BS EN 12464-1:2021 (Light and lighting – Lighting of work places).
Poor lighting is a leading cause of eye strain, migraines, and lethargy (Sick Building Syndrome). Compliance isn’t just a tick-box exercise; it is a fundamental requirement for employee wellbeing. A compliant lighting scheme balances three key factors:
- Visual Comfort: Reducing glare and flicker to prevent eye strain.
- Visual Performance: Providing enough light (Lux) to perform tasks accurately.
- Safety: Ensuring safe movement and emergency evacuation.
Required Lux Levels (BS EN 12464-1)
The amount of light hitting a surface is measured in Lux (lm/m²). The standard specifies maintained illuminance (Ēm), which means the light level must never fall below this value, even as bulbs age or get dusty.
| Area / Task | Lux (Ēm) | UGR limit (Glare) | Uniformity (U₀) | Ra (CRI) |
|---|---|---|---|---|
| Standard Desk Work Writing, typing, reading, data processing |
500 lux | 19 | 0.60 | 80 |
| Technical Drawing Precision work |
750 lux | 16 | 0.70 | 80 |
| Meeting / Conference Rooms | 500 lux | 19 | 0.60 | 80 |
| Reception Desks | 300 lux | 22 | 0.60 | 80 |
| Filing / Copying Areas | 300 lux | 19 | 0.40 | 80 |
| Corridors / Circulation | 100 lux | 28 | 0.40 | 40 |
| Stairs / Escalators | 150 lux | 25 | 0.40 | 40 |
Understanding Glare (UGR 19)
UGR (Unified Glare Rating) measures the psychological glare of a lighting installation. For offices, the limit is strictly UGR 19.
This is crucial for computer use. If lighting is too harsh or positioned incorrectly, it reflects off screens (veiling reflections), causing the user to squint. Over time, this causes headaches and neck pain.
LG7 Compliance: Often referred to as “LG7 Lighting”, this SLL guide emphasises that light shouldn’t just be directed down. It must also illuminate walls and ceilings (approx 30-50% of task illuminance) to create a balanced, cavern-free environment.
The Monitor Rule
Screens are self-illuminated. High background glare competes with the screen, forcing the eye to constantly adapt.
Emergency Lighting Compliance
Under the Regulatory Reform (Fire Safety) Order 2005, offices must have adequate emergency lighting to allow safe evacuation during a power cut.
Key Requirements (BS 5266-1):
- Escape Routes Must be illuminated to a minimum of 1 Lux along the centre line.
- Open Areas Anti-panic areas (>60m²) require 0.5 Lux minimum.
- High Risk Areas with dangerous machinery require 10% of normal illuminance (min 15 Lux).
- Points of Emphasis Lights must be placed near changes in level, stairs, firefighting equipment, and First Aid points.
*Emergency lights must undergo a short functional test monthly and a full duration test (usually 3 hours) annually.
Energy Efficiency & Part L
Building Regulations Part L mandates energy efficiency. Simply swapping to LED isn’t enough; controls are essential.
Occupancy Sensors
Lights should auto-dim or turn off when meeting rooms or toilets are vacant (Absence/Presence detection).
Daylight Harvesting
Sensors near windows should dim the artificial lights when natural sunlight achieves the 500 lux target.
Frequently Asked Questions
What are the standard lux levels for UK offices?
According to BS EN 12464-1:2021, standard desk work requires a maintained illuminance of 500 lux. Circulation areas typically require 100 lux, while precision technical drawing requires 750 lux. It is important to remember these are maintained levels, meaning the light level must stay above this point at all times.
What is UGR 19?
UGR (Unified Glare Rating) measures the glare produced by lighting. UGR 19 is the specific limit for office environments. It is designed to prevent eye strain and headaches associated with using computer screens (DSE work) by limiting harsh, direct light that could reflect off monitors.
What does LG7 lighting compliance mean?
LG7 compliance refers to guidance from the Society of Light and Lighting. It emphasizes that lighting should not just be directed downwards (onto desks) but must also illuminate walls and ceilings. Specifically, walls should have an illuminance of 50-75% of the ceiling, and ceilings should have 30-50% of the task illuminance. This reduces the “cave effect” and improves visual comfort.