Workplace Lux Levels to EN 12464-1: How to Get It Right?
How much light does a workstation really need? This guide explains the maintained illuminance values per task under EN 12464-1, the limits for UGR glare and colour rendering, and the practical sizing of luminaires.
View workplace luminairesWhat does EN 12464-1 require at the workplace?
EN 12464‑1 governs the lighting of indoor workplaces. The decisive figure is always the maintained illuminance Ēm in lux: the value the installation must not fall below over its whole service life, that is after ageing and soiling of the luminaires.
The standard does not judge the lux figure alone. For every task it defines a bundle of illuminance, glare limitation (UGR), uniformity (Uo) and colour rendering (Ra). Only when all four quantities are met is the workplace lit to standard.
- Ēm - maintained illuminance in lux for each task.
- UGR - unified glare rating, the lower the better.
- Uo - uniformity, ratio of minimum to average illuminance.
- Ra (CRI) - colour rendering index, 100 = ideal colour fidelity.
Which lux values apply per task?
The required illuminance rises with the visual task: the finer and lower in contrast the work, the more lux you need. Coarse storage and traffic areas manage with 100 to 200 lx, fine assembly and inspection call for 500 to 1000 lx, precision and colour control even more.
How do you size luminaires for the target value?
For a first estimate the lumen method applies: from the required lux value, the area, the maintenance factor and the room utilisation factor you get the necessary luminous flux in lumens and from that the number of luminaires.
- Set the lux target and area: required luminous flux = lux x area in m².
- Divide by the maintenance factor (for example 0.80) and by the room utilisation factor to offset losses.
- Choose luminaires with suitable efficacy (lm/W) and light distribution, LED saves 40‑60 % energy.
- Check the luminaire UGR and pick low-glare optics or louvres for screen workplaces.
- Match colour temperature to use: 3000‑4000 K neutral white for workshop and office.
Frequently asked questions
What does maintained illuminance mean?
The maintained value Ēm is the lux level the installation must not fall below over its whole service life. The new system is oversized via the maintenance factor so it still reaches the target after ageing and soiling.
How much lux does an office workstation need?
For writing, reading and data processing EN 12464‑1 requires a maintained value of 500 lx at UGR of 19 or less and Ra of at least 80. Finer visual tasks sit higher.
What does the UGR value tell you?
UGR is the unified glare rating. Lower values mean less direct glare. Office and screen workplaces require UGR of 19 or less, very fine inspection work UGR 16.
Why is the lux figure alone not enough?
Besides illuminance the standard demands glare limitation (UGR), uniformity (Uo at least 0.60) and colour rendering (Ra). Only their interplay makes a compliant workplace.
Light your workplace to standard?
We supply LED task and system luminaires with tested UGR and Ra values - matching the lux requirements of EN 12464-1.
Standard tested
Luminaires with documented UGR and Ra values to EN 12464-1.
Energy efficient
LED technology with high efficacy cuts running costs.
Measurably right
Lux values are plannable and checkable with a lux meter.
Expert advice
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