This paper uses a case study-based approach to empirically explore the relationship between indoor environment and workplace productivity in two naturally and mechanically ventilated office environments. Environmental parameters were continuously monitored over 19 months. Longitudinal surveys (online) recorded occupants’ perception of their working environment and self-reported productivity, while performance tasks (numerical tests, proof reading) measured cognitive capability.
Indoor temperature and CO2 concentrations were found to be higher and more variable in the naturally ventilated (NV) office. Occupant perception of their indoor environment strongly correlated with their perceived productivity in both case studies. Task performance was affected by indoor environmental conditions such as indoor temperature and CO2 concentration. Interestingly in the NV office the median scores were up to 12% lower for tests conducted at CO₂ levels >1400 ppm compared to those conducted below 1400 ppm, whereas in the MV office this threshold was 1000 ppm
