An evaluation of occupant perception and satisfaction of indoor environment in Leed-certified buildings in Nairobi, Kenya.

Abstract

The primary purpose of this study was to evaluate the occupant perception and satisfaction in indoor environment of LEED-Certified buildings in Nairobi, Kenya. LEED is an acronym for ‘Leadership in Energy and Environmental Design’. Developed by the United States Green Building Council (USGBC), the tool is used to rate the design and construction practices for green buildings. The principal objective of this study was toexamine the extent of perceived occupants’ satisfaction with various elements of IEQ and to determine their relationship with the perceived productivity of the users of LEED-Certified buildings in Nairobi County. The items in IEQ comprised of furniture and workspace layout, thermal comfort and air quality, lighting quality, acoustic quality, cleanliness, and maintenance quality. An occupants' satisfaction survey was used to collect the data required for the assessment of perceived occupants’ well-being as well as their interactions with their indoor environment, in selected LEED-Certified buildings in Nairobi. Interviews ,with key informants, were alsoconducted to supplement the data collected through administration of the questionnaire. The study’s population comprised of occupants (users) of LEED-Certified buildings and key informants (members of design and construction teams and facility managers).The primary data came from questionnaires issued to occupants of the case buildings and interviews with key informants. Secondary data was from books, journals, websites and facility managers' records. The primary data was analysed using frequencies, descriptive statistics (mean, mode, median, and others), measures of variability (standard deviation and variance) and the Pearson Product-Moment correlation. The correlation analysis was performed in order to determine the nature of the relationship between the variables. The study revealed that the users were very satisfied with the furniture and workspace layout. This was attributed to the ergonomic considerations in the design and layout configurations of computer-based workstations in case buildings. The study further established that the users were satisfied with acoustic quality, thermal 2 comfort and IAQ, lighting quality, cleanliness and maintenance quality of their workspaces. The results of correlational analysis established that the thermal comfort, lighting quality, acoustic quality, and cleanliness and maintenance quality had significant correlation while furniture and workspace layout had significant correlation with only acoustic quality and not the other variables. The study concluded that the assessment of the performance of indoor environment in LEED-Certified buildings was critically important if the management of organisations within those buildings were keen on improving the productivity of their workforce. The role of building occupants was also found to be critical in the appraisal of indoor environment as they were seen to provide valuable feedback essential for their successful management and enhancement of operational practices of LEED-Certified buildings. The objectives of the study were therefore fulfilled and the study recommended that conventional buildings in Nairobi be subjected to similar investigations while facility managers and designers of green buildings should find ways of improving the compliance with LEED standards and guidelines with a view of minimising the percentage of dissatisfied users. The social dimension, possibly accounting for much of occupants’ productivity, as well as the direct effect of LEED-Certification on property values in Nairobi were recommended as further areas of study.