AbstractThis article outlines the energy conservation measures in the civilian sector from a few different viewpoint regarding energy conservation in cities. First, the energy consumption trends in the business and residential sectors are discussed, focusing the importance of energy conservation measures in applications such as home heating, water heating and specific power demand. Second, as a measure to reduce energy demand itself, energy conservation by way of applying heat insulating materials to buildings and changing the life style of residents is considered. And from the viewpoint of improving the energy system efficiency, additionally discussed here are the measures to improve the efficiency of each energy equipment such as air‐conditioners and co‐generation equipment, and the characteristics of District heating and cooling systems such as the local energy infrastructures. Lastly, from the knowledge obtained through model analyses by the authors, a scheme is recommended that would be one of the most efficient city‐energy schemes where the energy systems including heat pumps, co‐generators or equipment using solar power are utilized for their best‐suited applications for business and residential customers. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.