The luminaires must be mounted at least 2 m above the floor, unless a mounting height of the luminaires of 2 m is not practical for special reasons (e.g. in outdoor areas, at assembly points, in safe places, in stairwells, in historical buildings, etc.). In this case, the lighting fixtures can be installed at a height lower than 2 m above the floor, provided that the safety objective is met.
Source: E DIN EN 1838, 4.1:2022