Building energy flexibility is being considered an emerging strategy allowing the demand side actively support the operation and control of variable resources-based energy supply. This study presents the development of a framework to formulate and aggregate energy flexibility indicators (EFIs) to evaluate building energy flexibility. EFIs were developed/selected using the important characteristics of building energy flexible sources, performance factors linked with flexibility services and penalty factors posed by the grid. A multicriteria decision analysis method was then used to develop an A...