The European standard EN 12464-1 sets the global benchmark for office lighting: 500 lux on the desk, UGR ≤ 19 (low glare), Ra ≥ 80 (decent colour), uniformity ≥ 0.6 (even spread), and 200 lux on surrounding walls. KSA's labour-comfort regulations align with these values. Get them wrong and productivity drops 20%.
Four ideas to carry into the next specification conversation you have.
Measured at 0.75 m height, on the desk, average across the area. Reception 300 lux. CAD drafting 750 lux. Accounts 500 lux.
Calculated in DIALux or Relux per CIE 117. Need diffused fixtures, lower luminance, and good aiming. Mandatory in EN 12464-1.
Standard offices Ra 80. Meeting rooms with frequent video calls or design studios use Ra 90+ for accurate skin and product colours.
DALI-2 or KNX sensors near windows dim luminaires when daylight is sufficient. Mostadam and LEED reward it.
Working-plane lux, UGR, CRI, and uniformity by office function.
| Space | Lux / UGR / Ra | Note |
|---|---|---|
| Reception | 300 / 22 / 80 | Welcoming, less critical |
| Open-plan desk | 500 / 19 / 80 | Standard task |
| Conference room | 500 / 19 / 80 | + video calls Ra 90 |
| Drawing / CAD | 750 / 16 / 80 | Highest UGR demand |
| Archive / filing | 200 / 25 / 80 | Storage transient |
| Server room | 200 / 25 / 80 | Maintenance only |
| Cafeteria | 200 / 22 / 80 | Social space |
| Corridor | 100 / 28 / 60 | Walkway |
Five build-quality decisions that move an office from compliant to excellent.
EN 12464-1:2021 introduced 150 lux on walls for offices. Why? Because vertical lux drives circadian (EP59), perception of brightness, and facial visibility. Designers must hit walls too.
Modern reports show UGR at every observer position, not just average. Worst-case observer at the back of the room dictates the design. NLC DIALux deliverables include this table.
6500K morning alertness + 4000K mid-day + 3000K evening reduces afternoon slump, improves sleep, and lowers staff turnover. ROI in 2-3 years from productivity alone.
Sensors must be placed where the actual daylight is, not where the BIM model said. Always commission with a real desk and a real day, sensor placement is field-tuned.
The 2021 revision added wall lux, ceiling lux, modelling, and SDCM ≤ 5. Mostadam Silver/Gold projects require compliance. Don't quote the old 2011 standard.
Our office panel and linear systems ship with UGR ≤ 19, Ra ≥ 80, SDCM ≤ 3, and DALI-2 ready. Mostadam-compliant out of the box.
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