Low speech privacy in shared and private offices in one of the early generation of a “green” building resulted in occupants' dissatisfaction. This problem is experienced in Liu institute with a natural-ventilation system. Such a system requires low air-flow resistance which is achieved by large openings which will result in noise transmission between various spaces within the building. The poor acoustical quality in this building resulted in occupants' noise complaints which were further investigated by way of relevant acoustical measurements. CATT-Acoustic software was utilized to modify the acoustical quality of the building without any disturbance to the occupants. The optimized design of the transfer box above the office door was selected based on CATT-Acoustic predictions. The acoustical measurements were conducted after installation of the transfer box above the office door. The measurements' results agreed with the predictions which led to improved speech privacy to an acceptable level between the office and the corridor in Liu Institute. More work should be done to improve the acoustical quality of natural-ventilated building to conform to ANSI standards. 1 The results of this study strongly support including acoustics in “green” building designs with natural ventilation to avoid users' complaints.