中文摘要：

研究不确定条件下分阶段的既有建筑节能改造项目投资评价方法，是顺应全面建筑节能改造形势，体现投资灵活性，确保既有建筑节能改造市场良性运行的重要内容。在对既有建筑节能改造项目投资的期权特性进行深入分析的基础上，考虑到项目投资价格具有非连续性，采用二叉树定价法计算不确定条件下项目的延迟期权与扩张期权的复合价值，对传统净现值方法计算的项目价值进行补充，较为全面地反映既有建筑节能改造项目真实的投资收益，为既有建筑节能改造项目投资评价提供了新的思路。对波动率的敏感性分析表明，项目复合期权价值随着不确定性增加而提高，适时地做出追加投资的决策将具有更为显著的投资效益．

英文摘要：

In order to follow the overall building energy-saving situation in China and reflect the investment rationality and flexibility, it is in urgent need to investigate the investment evaluation methods of building energy efficiency retrofitting （BEER） projects under uncertainty to guarantee a sound operation in energy saving market. In this paper, based upon an in-depth analysis of BEER projects＇ option characteristics, considering the discontinuity of BEER projects＇ value, the binary tree pricing model is used to evaluate the composite value of a delay option and an expansion option of these projects under uncertainty to supplement their NPV and achieve a more comprehensive estimated investment income. Sensitivity analysis of volatility further shows that the composite option value is increasing with enhancing uncertainty and timely additional investment will have more significant returns in BEER projects. The proposed method and the analyzing results will provide a new tool in investment evaluation of BEER projects in China.