Workspace Lighting Standards (EN 12464-1, IS 3646)
The international and Indian standards behind office lighting, what they require, and how to apply them on real projects.
The Two Standards That Matter
EN 12464-1 (Europe) and IS 3646 (India) define what professional office and workspace lighting must achieve. Both reference lux, UGR, uniformity and CRI as the four core metrics.
Core Requirements
| Metric | Open Office | Meeting Room |
|---|---|---|
| Lux (working plane) | 500 | 500 |
| UGR | ≤ 19 | ≤ 19 |
| Uniformity (U0) | ≥ 0.60 | ≥ 0.60 |
| CRI | ≥ 80 | ≥ 80 |
What These Numbers Mean in Practice
- Lux is on the working plane, typically 0.75m
- UGR is calculated from realistic observer positions
- Uniformity = minimum lux ÷ average lux on the working area
- CRI 80 is the floor; CRI 90+ for client-facing zones
Common Mistakes
- Treating lux as the only target
- Skipping UGR because it requires DIALux
- Designing for average lux without checking uniformity
- Ignoring W/m² energy targets
Professional Recommendation
Specify Lux, UGR, Uniformity, CRI and W/m² together on every workspace. They form a complete brief, leaving any one out invites failure on site.
Lighting Intelligence by Alya
At Ashwamedha Design Solutions, this is part of our Lighting Intelligence practice, every recommendation is validated through DIALux simulation, lux calculations and visual comfort analysis before it reaches a construction site. Alya, our lighting intelligence platform, packages this thinking into reusable design tools.
Frequently Asked Questions
Is IS 3646 mandatory in India?+
It is the reference for office lighting and is widely cited in NBC and LEED certification submissions.
Can I exceed 500 lux on a desk?+
Yes, particularly for paper-heavy tasks. But over-lighting raises energy and discomfort, calibrate by task.
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