Buildings consume about 40 percent of total national energy use, are responsible for the same percentage of greenhouse gas emissions, and account for about 70 percent of electricity use. To address energy security issues and environmental concerns there is an urgent need to develop techniques that greatly reduce energy use and peak electric power in buildings while providing or improving service. One of the greatest opportunities to address this need is to accelerate the development and deployment of advanced building energy information and control systems that improve energy efficiency. These information and control systems need to be responsive to demands and dynamic prices from the electricity grid by modifying electric loads during operations, while meeting needs of building occupants. This paper reviews progress in each of these areas and suggests how future integrated control systems should be designed and operated to ensure that buildings are both efficient and demand responsive for optimal low-cost operations.