Sick building syndrome was investigated in a newly built office building. Information about health complaints from the employees was obtained by means of a self-administered questionnaire. Measurements of microclimate conditions and air pollution levels confirmed that the employees' complaints were justified. Because of a high percentage of complaints, the questionnaire was evaluated by means of factor analysis. The results showed logical grouping of the complaints and/or symptoms, suggesting credibility of the answer. Factor analysis proved to be an appropriate tool for detecting and evaluating sick building syndrome.