Residential energy consumptions for space heating depends on climate conditions, floor areas, dwelling structures, thermal insulation performances, types of heating supply systems, inhabitant preferences. A standard indicator of space heating services independent of above conditions is advanced based on actual measurement values on 61 dwellings in Japan area on this paper. The indicator is calculated using average room temperatures during a space heating period, room floor areas and numbers of space heating days. A space heating efficiency in a dwelling can be analyzed by examining the correlation between the indicator and energy consumption. The dwellings having electric storage thermal heating systems or electric boilers consume larger energy for their space heating standards. An efficiency of a space heating by air conditioners cannot be observed in this study.