How to light a classroom
A classroom is an office with two working planes: the horizontal desk and the vertical board. Solving only one of them is the most common mistake.
- Maintained illuminance
- 300–500 lx (pizarra 500)
- Glare (UGR)
- ≤ 19
- Colour rendering
- ≥ 80 (recom. > 90)
- Colour temperature
- 4000 K
- Uniformity
- ≥ 0,60 (pizarra 0,70)
EN 12464-1 requires 300 lux on desks in conventional classrooms and 500 lux in adult education, technical training or drawing rooms. The board needs 500 vertical lux with uniformity ≥ 0.70: it is the plane the whole class looks at for hours.
Glare is as critical as in offices (UGR ≤ 19) because students look up and forward far more than office workers, and today almost every classroom has screens or a projector.
4000 K supports alertness and concentration during the school day. In nursery or rest areas, 3000 K is more appropriate for its welcoming character.
With a projector, the key is row-by-row dimming: switching off or dimming only the row nearest the screen keeps the rest of the room lit for note-taking instead of plunging the class into darkness.
- Install a dedicated board luminaire (asymmetric or wall washer): general lighting never covers it properly.
- Run luminaires parallel to the window wall to make the most of daylight.
- Avoid reflected glare on desks: choose matt finishes and shielded optics.
- Provide row dimming: the board row independent from the rest of the classroom.
