EVALUATING INDOOR ENVIRONMENTAL QUALITY AND ITS EFFECT ON USERS’ PERFORMANCE

Abstract

It is vital for the building design to address its users’ needs as they spend 90% of time indoors. Indoor environmental quality (IEQ) refers to the conditions inside the building having impact over human performance, health, and wellbeing. Satisfied and comfortable occupants are generally performing in higher levels and more productive. Comparing occupants’ salaries over building’s life cycle with the initial cost reveals that installing efficient indoor environmental quality IEQ strategies from the beginning would be more economic. By investigating how each factor of Indoor environmental quality (IEQ) could affect human performance positively when properly designed or negatively at poor conditions, both building designers and owners would be keen on installing IEQ strategies promoting building users’ satisfaction. As certifying buildings with Leadership in energy and environmental design (LEED) rating system is constantly increasing in Egypt, and IEQ category is frequently obtained in majority of certified buildings, the effect of this certification on the actual situation of IEQ needs to be examined.

This research aims at evaluating the state of indoor environmental quality (IEQ) specially in Leadership in energy and environmental design (LEED) certified office buildings by performing a post occupancy evaluation (POE). The research is carried out in two parts: theoretical and analytical. The theoretical study addressed main aspects of IEQ including thermal comfort, indoor air quality (IAQ), visual comfort, and acoustics. It also investigated the positive and negative impacts of these factors over office occupants’ performance and health in addition to IEQ evaluation methods and criteria. The analytical study is represented in a post occupancy evaluation using self-assessment questionnaire method. Two LEED certified office buildings were chosen to perform study. Both buildings have significant sustainability features and high certification levels varying between gold and platinum. Both buildings are located in greater Cairo and adopting the concept of open-plan layout. Data collected from each building was independently analyzed and compared with standard recommendations with no comparison with the other building as it is not the intent of the research.