question: As a result of COVID-19 and in order to combat the spread of the virus, work-from-home and remote working has become a widely accepted practice in professional settings globally. It is widely known that we are currently experiencing a highly transient period in terms of how we define work. Office work is progressively becoming more collaborative, modern workforce more mobile, and office occupancy more dynamic. As flexible working evolves, it becomes apparent that the role of workspace is also changing. So will the occupancy patterns and operation of office building. Using a mixed-method approach, this paper explores the future of offices, considering flexible working model and investigates the operational energy consumption of UK office buildings in the post-pandemic era. Previous research has shown that office buildings are one of the five largest sectors in the building stock in terms of energy consumption. The results of this study demonstrate that by embracing emerging transitions in hybrid working model and activity-based workspace environments, the energy demand in the office building sector could fall below pre-COVID-19 levels, with significant energy savings reaching up to 50% energy reduction in comparison to the pre-pandemic situation.