In a Nordic cooperation project the acoustical conditions in open-plan offices was investigated. Measurements have been carried out in five open plan offices accompanied with an inquiry gathering the subjective judgments by the staff. A program for the acoustical measurements was designed specifying how to perform the measurements and which type of parameters to measure. The acoustical parameters included in the measurements are Reverberation time T20, Early Decay Time (EDT), Clarity (C50), Speech transmission index (STI), Speech intelligibility index (SII), Privacy Index (PI), Rate of spatial decay of sound pressure levels per distance doubling (DL2 ), Excess of sound pressure level with respect to a reference curve (DLf), background noise levels in occupied and unoccupied offices. In two of the offices a refurbishment program was carried out. Measurements as well as questionnaire were accomplished after refurbishment. The effect on room acoustic parameters DL2 and DLf and on subjective judgments by the staff will be presented in this paper.