Although light levels are fundamental for a lighting scheme, many people fail to consider the effects of natural light. Excessively high light levels can cause eye strain and tiredness. Too low and people will struggle to carry out their everyday tasks. This applies regardless of whether the light comes from an artificial or natural source meaning that your client may be working in less than ideal light levels depending on the time of day or season. This is why incorporating lighting controls that give the user flexibility is important. This can either be by giving them control over the overhead lighting close to their working area or providing task lighting such as desk lamps.
Another important factor is the Unified Glare Rating (UGR). This is a relatively new measurement that takes into account the visual comfort of an observer from a specific position (i.e. workstation, desk). Failing to take this into account will result in reduced visibility and comfort in the workplace. We use lighting design software such as Relux or Dialux to carry out these important calculations for you. The lower the rating, the better; typically for an office the recommendation is for a UGR of less than 19.
Visual discomfort can also be reduced by decreasing the contrast between surfaces. The main factor to consider here is ceiling brightness, a dark ceiling will contribute towards visual discomfort. However, a solution to this requires additional lighting elements to illuminate the ceiling which would increase power usage. This creates a compromise between energy efficiency and visual comfort. 
We’re happy to advise on how to get the best results for your budget.
