Buildings account for nearly 40% of energy consumption in the United States. To improve energy efficiency and reduce peak demand, intelligent building management systems can be developed to manage the energy consumption of flexible loads such as heating, ventilation, and air conditioning (HVAC) system an electric vehicle (EV) charging, as well as the usage of energy storage systems such as batteries. In the case where a building cluster is managed by the same institution, coordinating the energy consumption behavior across multiple buildings can provide further benefits in energy efficiency. In this paper, we first invest gate an integrated co-scheduling scheme that uses a joint formulation to optimize the control of HVAC systems, EV charging a d battery storage in multiple buildings for reducing the overall energy cost. Then, we further explore a more efficient heuristic scheme where the shared battery storage and EV charging demand are assigned to each building for separate building-level scheduling. Our experiments demonstrate the effectiveness of our co-scheduling scheme and separate-scheduling heuristic in reducing energy cost for building clusters.