Based on the disadvantages of existing building environmental analysis methods, a generic model of exergy analysis on environmental impact of building life cycle is introduced, taking into consideration of previous models and focusing on natural environment as well as building life cycle. And three environmental impacts were analyzed, namely energy consumption, resource consumption and pollutant discharge respectively. The generic model of exergy assessment on environmental impact of building life cycle thus was formulated and building environmental sustainability was evaluated through exergy footprint of building environmental impacts. With a residential building in Chongqing for case study, it was found that environmental impacts in building operational stage accounts for 88% of building life cycle and in the breakdown, environmental impacts from energy consumption and related emission were the fundamental parts with the share of 75% and 24% respectively. And for sustainability analysis, about 169 m2 earth areas with global average productivity was required to support the building’s life cycle of one m2 floor area.