Impact of indoor environment quality parameters on occupant satisfaction and energy efficiency: building professionals' perspectives

Sustainable retrofit can increase a building's performance and extend its lifetime. Common sustainable retrofit guides usually ignore the building’s indoor environmental quality (IEQ) and occupant satisfaction while only focusing on energy efficiency. During the retrofit, prioritizing improvements to IEQ parameters that are critical for increasing occupant satisfaction but do not considerably increase energy consumption is crucial given the budgetary constraints. This project aims to identify different building experts’ perspectives on the impact of IEQ factors that contribute to occupant satisfaction and energy efficiency in office buildings. The study surveys the views of 30 carefully selected building experts (ten architects, ten building engineers, and ten building assessors) in Australia using multiple criteria decision-making method. Results showed that the building engineers and assessors regarded thermal comfort as the most critical factor influencing occupant satisfaction, 54.2% and 57.6%, respectively. They believed that temperature control and relative humidity were the parameters with the highest importance in office occupants' overall satisfaction. Alternatively, the architects regarded visual comfort as the most important (38.8%), particularly parameters of daylight availability and outside view. The opinions were more similar regarding the energy consumption required for supplying suitable IEQ in office buildings. All expert groups believed that thermal comfort needed the highest energy demand, followed by indoor air quality. They all agreed that temperature control, vertical temperature variation and mechanical ventilation were the IEQ parameters with the most energy implications.