Regulating indoor air environment is one of the core functions of building energy management system. Heating, ventilation, and air-conditioning (HVAC) control systems play an important role in adjusting the room temperature to provide occupants a desired level of comfort. Occupant comfort has a direct effect on the energy consumption and providing an optimal balance between comfort and energy consumption is a challenging problem. This paper presents a framework for control of building HVAC systems using a methodology based on power-shaping paradigm that exploits the passivity property of a system. The system dynamics are expressed in the Brayton-Moser (BM) form which exhibits a gradient structure with the mixed-potential function, which has the units of power. The power-shaping technique is used to synthesize the controller by assigning a desired power function to the closed-loop dynamics so as to make the equilibrium point asymptotically stable. The proposed methodology is demonstrated on HVAC subsystems: RC network building zone model and a heat exchanger system. © 2017 by ASME.