Using the towns and suburbs of major cities with large populations of over 100,000 people as case studies, this research predicts the scenarios for the feasibility of low-carbon regional community systems. Specifically, using energy conservation plans formulated by government institutions as a foundation, it builds coordinated schemes and makes predictions that consider transformations in resident lifestyles including, changes in resident characteristics that take place alongside shifts in demographics, future trends concerning the specifications for devices in use, and the further permeation of a more energy-conserving lifestyle.