Towards sustainable workplaces : effects of indoor environmental quality on occupant comfort and work performance

Abstract

Greener buildings have been produced to reduce environmental impacts and improve the quality of life for their occupants. Accordingly, indoor environmental quality (IEQ) has received attention since it is believed that IEQ affects occupant comfort, health and productivity. Green buildings particularly have not only direct benefits from saving operating costs, but also indirect benefits from improving worker productivity through better IEQ. Despite substantial research on this topic there is little emphasis on building occupants, the end-users who are most experienced in the building with the ability to adjust to their environment. Although the biggest effort to produce high performance green buildings has been made with a focus on green design and technologies there seems lack of post-occupancy evaluation (POE) studies in the context of the fastest growing and high density Asian cities. The primary aim of this study is to examine the causal relationships between the indoor environment and occupant response including comfort and work performance in office buildings, within the context of building sustainability. A comparative POE study was conducted in Seoul, South Korea. Two sources of data were accessed using a physical environment checklist and an occupant questionnaire from nine, ‘Green’ and ‘Conventional (non-green)’ office buildings. Four stages of data analysis have been conducted to test the hypotheses involving physical conditions, comparisons of the occupant perceptions between ‘Green’ and ‘Conventional’ buildings, occupant evaluations of aggregate data, and comparisons between objective and subjective evaluations. The physical conditions of the buildings do not seem to be significantly different between ‘Green’ and ‘Conventional’ buildings in terms of the indoor environment although the green buildings demonstrate more green features than the conventional buildings. Similarities and differences have been identified between ‘Green’ and ‘Conventional’ buildings. It has been verified that thermal comfort and indoor air quality are the most influential factors among the IEQ components, contributing to overall environmental comfort. The last part of the data analysis validated that the occupant subjective evaluations of the environment did not always seem to be correlated to the objective measurements of building conditions. Most interesting result of this study is that job satisfaction is more strongly associated with productivity than work performance. An interpretation is that job satisfaction supports organisational productivity rather than the individual work performance itself does.