Purpose The purpose of this paper is to determine the effects of environmental factors in open-plan offices with the same characteristics but with different workstation partition heights (1.10, 1.40 and 1.65 m) on perceptual evaluations of office employees. Design/methodology/approach In this research, the effects of environmental factors on employees’ perceptual evaluations in open-plan offices at the Gölbaşı Region of Ankara were measured with a detailed questionnaire. The research data were obtained from 81 employees who agreed to fill out the questionnaire and who use open-plan offices. Findings It was found that the office environments with 1.65 m workstation partition heights were more favorably assessed for each of the items of planning and of privacy that form the dependent variables compared to the office environments with 1.10  and 1.40 m partition heights. On the other hand, the office environments with the 1.10 and 1.40 m partition heights were more favorable for lighting items than the 1.65 m partition height office environments. In addition, young employees had a more positive tendency toward the perceptions of environmental factors, including different workstation partition heights in open-plan offices, compared to older employees. Research limitations/implications Results of this research provide a fundamental contribution for the impact of various partition heights that have substantial implications on the perceptions of open-plan office environments. At this point, as open-plan offices have important effects on the quality of employees’ work experiences, the influence of various partition heights on the performance of employees should be emphasized in future studies. The diversity of performance (reading comprehension, calculation, design, drawing, etc.) will be an important decision. Originality/value The significant contribution of this research is that it provides valid data and makes a valuable contribution to the body of knowledge in open-plan office design.