international catalogue

North America catalog

unified glare rating

Good office lighting is an important factor influencing employees’ performance and general working conditions. A light source that is installed and adjusted incorrectly can cause glare, fatigue and visual difficulties. It goes without saying that these factors can affect productivity and concentration.  

The Unified Glare Rating can help you ensure that your office is optimised. We will explain briefly what this means and how this rating is measured.

what is UGR?

Unified Glare Rating, UGR for short, is an indication of the extent to which a light source causes glare and light pollution. The higher the value, the more light pollution there is. Given the fact that the right lighting ehas a major impact on people’s productivity and performance, this rating is very important when allocating light fittings within a lighting plan.

Glare can occur in two ways:directly and indirectly. In the case of direct glare, the light source shines directly into the eyes or face. Indirect glare, on the other hand, refers to the reflection of the light source on a reflective surface.

how is the unified glare rating measured?

When measuring the UGR, we must consider a number of important factors:

  • The size and shape of the space in which the light source is present
  • The distribution of light fittings across the space
  • The surface brightness or luminance of the walls, ceiling, floor and other large surfaces (white walls, for example, reflect lots of light)
  • The type of light fitting and barrier
  • The position of the observer

Foto 03.11.15-2-532949-edited

various quality levels and the official standard

There are 5 different quality levels in the Unified Glare Rating: 16, 19, 22, 25 and 28. These indicate the optimum UGR rating for specific rooms. The average UGR rating lies between 15 and 30, however, some places require good lighting without pollution in order to best serve their particular purpose.

Some such examples are:

  • A corridor: <2
  • Stairwell, lifts and archive areas: <25
  • Office space: <19
  • Drawing/design offices: <16

If the UGR rating is below 10, there is considered to be no glare. In this case we refer to ‘zero glare’. The particular quality level to be applied to a specific space is officially determined in a European EN standard, namely the NEN-EN 12464-1 standard.

It is also important to mention that the UGR rating is not a characteristic of a light fitting. It is the combination of the brightness of the light fitting, the brightness of the environment and the interaction between our position and the corner. The brightness of a light fitting can be adjusted, but this is not the case for the other two factors. This also means that the UGR rating is variable, despite what is often thought.

the right experience with kreon lighting

kreon offers timeless lighting, which is designed to be fully integrated into the architecture or to form a dialogue with the room structure. Our collection features a series of light fittings that are harmoniously blended into ceilings, floors and walls. In this way we create instinctive lighting and prevent unpleasant light pollution.

Would you like to know more about our lamp collection? Please contact our specialists. They would be delighted to give you the relevant advice.

Tools of light CTA

Back to blog overview