Lighting quality surveys in office premises

The lighting quality in an indoor space affects the productivity, comfort, well-being a nd health of the occupants. In this article a lighting quality index called the CSP index is briefly reviewed and two office lighting quality surveys are described. Data from a large scale lighting quality survey show a very poor correlation between the CSP index and the occupants' subjective assessment of the lighting quality. Surveys before and after a lighting retrofit project that consisted of two stages are also reported. Results show that the occupants preferred the higher light levels after the retrofit. However, the data also show that a higher percentage of occupants reported that they suffered from headache or eyestrain after the retrofit. Therefore, it is not clear whether the lighting quality overall was improved by the retrofit. Copyright (C) 2001 S. Kargei AG, Basel.