With an economic growth in GDP of around 10% per annum in recent years, energy consumption in the building sector in China now accounts for 25% of the total energy use in the whole nation. In large buildings in Beijing and Shanghai the consumption rate, at approximately 190 kWh/m2 per annum, is around five times the energy use in residential buildings in those cities. Addressing this ever increasing energy consumption and the consequential green house gas (GHG) emissions must be a priority to achieve low carbon sustainability in China. As part of the Kyoto Protocol the Clean Development Mechanism (CDM) has been used to assist in the finance of GHG reduction projects in developing countries in the context of low carbon sustainable development. However, hitherto the majority of CDM projects of an energy related nature have focussed almost exclusively on renewable energy projects or those which enhance the efficiency of industrial processes. To date the opportunities for using the CDM approach in reducing emissions in large buildings have been largely overlooked in China and other countries. Part of the reason is the lack of an adequate established baseline methodology against which the impact of any proposed CDM project can be judged. This paper explores the barriers to the implementation of carbon reduction strategies in large commercial buildings using China as a particular example.