Office Lighting: Lux Levels, Glare Control and LED Planning to EN 12464-1

In an office, lighting is judged not in lux but in headaches, concentration and reflections on the screen. EN 12464-1 sets clear values, but good office lighting only happens when illuminance, glare, colour temperature and controls work together. This guide shows the values per room and how to plan an office that is compliant and pleasant.

Lux levels per office area

Area	Illuminance	UGR max.	Ra min.
Writing, reading, screen work	500 lux	19	80
Technical drawing, CAD	500–750 lux	16–19	80
Meeting and conference room	500 lux	19	80
Reception	300 lux	22	80
Archive, filing	200 lux	25	80
Corridors and circulation	100 lux	28	40
Stairwell	100–150 lux	25	40

The values follow EN 12464-1 and are maintained values. The task area is the desk; the immediate surroundings may be one step lower. What the UGR value means exactly is explained in UGR Value Explained.

Glare and screen work

At screen workstations, problems almost always come from glare, not from too little light. Bright luminaires reflect in the monitor, and overly bright surfaces in the field of view tire the eyes. Therefore:

• Use luminaires with UGR<19, meaning a microprismatic diffuser or louvre instead of an opal cover.
• Arrange rows of luminaires parallel to the windows and to the side of the line of sight to the monitor.
• Keep ceilings and walls light so the contrast with the luminaire stays low.

Whether a backlit or edge-lit panel suits better is compared in Backlit vs. Edge-Lit LED Panel.

LED panels for offices

Colour temperature in the office

4000K (neutral white) is the standard: focused but not cold. 3000K suits meeting and reception areas when a homelier atmosphere is wanted. Panels with switchable colour temperature (CCT) let you set each room individually. More in LED Colour Temperature.

Controls: presence and daylight

• Presence detectors: Lights off when nobody is in the room, ideal for meeting rooms, corridors and toilets.
• Daylight control: Luminaires on the window side dim automatically when there is enough daylight.
• DALI: For larger offices with changing layouts and scenes, DALI is the most flexible solution (see Dimming systems compared).

Worked example

An office floor with 100 grid luminaires 4 × 18W fluorescent (approx. 80W with ballast) is replaced by 100 LED panels of 36W, 2,500 hours a year, €0.28/kWh: saving 100 × 44W × 2,500 h = 11,000 kWh, around €3,080 a year. Presence detectors add another 20–30%. See LED Payback Period Calculator.

Frequently asked questions

How many lux does an office workstation need?

500 lux at the task area under EN 12464-1, with UGR no more than 19 and Ra at least 80.

What does UGR<19 mean?

The UGR value describes discomfort glare. Values below 19 are considered suitable for screen and desk work.

Which colour temperature is best for offices?

4000K neutral white for workstations, 3000K for reception and meeting areas if a homelier feel is wanted.

Can I simply replace old grid luminaires with panels?

Yes. 60×60 and 62×62 LED panels fit directly into most grid ceilings, with the driver included.

Are presence detectors worthwhile in offices?

Especially in meeting rooms, corridors and washrooms. In single offices they typically save 20–30%.