In this paper, demand side resources and economics are analyzed based on 100 domestic building’s power usage data in 2011. In order to participate in demand side management or response program, there is a barrier of a large amount of capacity reduction. The demand side resources in domestic are focused on industrial area but there is a need to find a variety of demand side resources from buildings. To find demand side resources, power usage and existing power equipment are investigated and analyzed for actual office buildings. The result says that an emergency generator operated at no load condition for maintenance during 12.9 hours per month. Considering demand side resource, it is identified that participating demand response program and economic evaluation are secured at the same time.