Prefabrication has been considered an effective alternative to conventional building. It has gained an increasing amount of attention over the last few decades as a way to advance sustainable construction. This study focused on the construction stage to compare sustainable performances of prefabrication with conventional building. Sixteen indicators were extracted from a literature review and specialist interviews to conduct a sustainability evaluation. A survey was delivered to developers, designers, superintendents, manufacturers, and contractors of a Chinese case project. A total of 51 valid responses were collected. Projection pursuit (PP), based on the real-coded accelerating genetic algorithm (RAGA), was employed to evaluate the sustainability of prefabrication. The results showed that there was a consensus among the participants that prefabrication has more obvious sustainable performances in the construction phase compared with conventional building. However, cognitive differences among the participants regarding the sustainability of prefabrication were also pronounced. The findings presented in this paper may assist the government to propose feasible policies and measures to promote the development of prefabrication in China.