Field measurements of perceived air quality were conducted in four refurbished offices at the Czech Technical University in Prague. The offices were refurbished as part of the research project Clear-up to serve as a field test facility. The present paper describes measurements conducted to investigate the perceived air quality, sensory pollution load and concentration of Volatile Organic Compounds (VOCs) in the offices. As the refurbishment comprised also installation of demand controlled ventilation (DCV), its influence on the perceived air quality was also tested. Measurements comprised the assessments of perceived air quality and objective measurements of operative temperature, relative humidity, CO2 and VOCs concentrations. Results showed that the mean sensory pollution load in unoccupied offices was 0.09 ± 0.01 olf/m2 (mean ± SEM). This falls into the category of a low-polluting building according to CEN Report CR 1752. The acceptability of the air quality was worst in unoccupied offices ventilated with minimum air change rate (0.4 h-1). Application of DCV decreased the CO2 concentration, but did not result in statistically significant improvement of perceived air quality.