The high-rise residential buildings of China will soon need retrofitting and any such retrofitting should include consideration of new energy saving methods and 'green' technologies. A research agenda is needed to meet this challenge. This paper presents a research agenda for the 'green' retrofitting of residential buildings. The agenda is based on the input of 25 national and international experts which was produced by a novel methodology specifically designed to discuss the key questions relating to the retrofitting of residential buildings. This methodology, based on Problem Tree Analysis, proved an effective method of producing an agenda for the research that is needed to facilitate such change. The research needs are presented under six headings. Stages for undertaking the research activities under each of these headings have been identified. The agenda highlights that the challenge of retrofitting is holistic and includes not just engineering and construction actions but economic, social and governmental requirements. Key aspects of the research agenda include the need for better macroeconomic and micro-economic models and a better understanding of people's needs and expectations. These topics are discussed together with recent research findings both from China and other countries.