Conceptual design is one of the most important stages in building design, and energy efficiency analysis is one of the key issues in building conceptual design stage. The existing energy efficiency analysis methods and tools require inputing large number of parameters. However, the detail information of most parameters is not identified at the stage of conceptual design. And the current prevailing energy consumption simulation methods and tools are not appropriate at the stage of conceptual design. The proposed method can be used to compare the energy efficiency of multistrategies at the conceptual design phase. Minimum data were required to be input for achieving the optimal building design scheme. The method can provide a solution to the gap between the rapid building design cycle and the sustainable development demand in China.