What are space UGR values?

For standard rooms (rectangular, no furniture, only one type of luminaire), the four standard UGR values for the left and lower walls for the direction of view transverse and longitudinal to the luminaire are given on the single-sheet output or on the summary. This eliminates the need for manual calculation using the standard table.


1. A UGR table is created for the luminaire.

2. Then it is determined which combination of reflectance (wall /useful plane /ceiling) in the UGR table comes closest to the real room, as well as which room geometry comes closest to the specified values in the UGR table. The arrangement of the luminaires in the real room is irrelevant here.

3. The 4 UGR values are then read from the table on the basis of the combination of reflectance and room geometry determined in this way.


The room UGR values are only displayed if the following conditions are fulfilled:

  • The room is rectangular.
  • Only one type of luminaire is available.
  • The luminaire is rotationally symmetrical or C0-C180- and C90-C270-symmetrical.
  • No furniture available.
  • 2.0 <= room width/luminaire height <= 12
  • Room width/luminaire height >= 12 or room length/luminaire height <=12
  • Room width/luminaire height unequal to 12 or room length/luminaire height <= 8