The Impact of Occupants’ Behaviours on Energy Consumption in Multi-Functional Spaces

Over the last 15 years, the estimation of energy consumption in buildings has become a critical process during various stages of building’s lifecycle due to growing global scientific and political pressure to respond to climate change. It has been widely acknowledged in the literature that there is a distinct performance gap between predicted and actual energy consumption of buildings which has attracted scholars across the world to investigate the sufficiency of software inputs and presumptions regarding how the buildings are actually used. Several studies have confirmed that occupant’s presence, in addition to, their interactions with building systems (such as: opening door and window, changing the thermostat set-point and using appliances), known as passive and active energy consumption behaviours, play significant roles in building’s energy consumption. However, the incorporation of occupants’ behaviours into the building energy performance analysis has been mostly overlooked.

Most of the existing studies on the impacts of occupants on building energy consumption have focused on residential and office buildings. Therefore, there is a lack of knowledge about the impacts of occupants’ behaviours on energy consumption in public buildings such as: galleries, exhibitions, recreational facilities and institutional buildings. In such building occupants have limited access to building systems, and their energy consumption behaviours are limited to their presence and the production of metabolic heat (passive behaviour), in addition to, few activities such as: opening the entrance door.

This research develops a conceptual framework to improve the accuracy of energy consumption assessment in multi-functional spaces at different stages of building’s lifecycle by integrating the impacts of occupants’ behaviours into building energy predictions to reduce the gap between actual and predicted energy consumption. In this quantitative research, a model simulation method is applied on multiple cases at different stages of the building lifecycle including design, construction and post-occupancy. The first two cases are multi-functional spaces of public buildings at the design and construction stages, which were studied to address the missing information and potential gaps in energy modelling and simulation. The study was then taken forward using case studies at the post-occupancy stage to integrate the realistic observed data into the building energy simulation tool. For each of the cases, energy simulation was run twice: first, using default values of the software, and second, using the collected data. The data collection included hourly observation of 38 zones in both cases at the post-occupancy stage for the duration of two weeks, in addition to, using available governmental and real-time statistics.

The analysis of energy simulation results using default software values and collected data highlighted that lack of sufficient information regarding building working hours, space layout and function, occupancy density and schedules, the entrance door opening time and HVAC set-points may result significant performance gaps in energy consumption prediction of multi-functional spaces in institutional buildings and galleries.

This study provides conceptual frameworks for the prospect energy modellers and researchers to obtain more accurate energy consumption predictions for multi-functional spaces of public buildings.