Energy management in buildings is the control of energy use and cost while maintaining indoor environmental conditions to provide comfort and to fully meet functional needs. This chapter provides guidance on establishing an effective, ongoing energy management program, as well as information on planning and implementing energy management projects. The energy manager should understand how energy is used in the building, to manage it effectively. There are opportunities for savings by reducing the unit price of purchased energy, and by improving the efficiency and reducing the use of energy-consuming systems. Water/sewer costs and use may be included in the energy management activity. This could be called “utility management,” but “energy management” is used in this chapter. Energy and Water Management Communications Energy and Water Accounting Systems Analyzing Energy and Water Data Surveys and Audits Improving Discretionary Operations Energy- and Water-Efficiency Measures Implementing Energy-Efficiency Measures Monitoring Results Evaluating Success and Establishing New Goals Building Emergency Energy Use Reduction