『Abstract
　In order to promote energy efficiency and emission reduction, the importance of improving building energy efficiency received sufficient attention from Chinese Government. The heat metering and energy efficiency retrofit for existing residential buildings of 0.15 billion m² in northern heating regions of China was initiated in 2007 and completed successfully at the end of 2010. This article introduced the background and outline of the retrofit project during the period of 11th five-year plan. Numerous achievements that received by retrofit such as environmental protection effect, improvement of indoor environment, improvement of heating system, investment guidance effect, promotion of relevant industries and increasing chances of employment were concluded. Valuable experience that acquired from the retrofit project during the period of 11th five-year plan was also summarized in this article. By analyzing the main problems emerged in the past, pertinent suggestions were put forward to promote a larger scale and more efficient retrofit project in period of 12th five-year plan.

Keywords: Retrofit project; Heat metering; Energy efficiency』

1. Introduction
　1.1. Background of the retrofit project
　1.2. Significance to implement the retrofit
　1.3. Outline of the retrofit project
2. Achievements
　2.1. Environmental protection effect
　2.2. Improvement of indoor environment
　2.3. Improvement of heating system
　2.4. Low-carbon economy
3. Experience
　3.1. Investigation and research should be conducted before planning
　3.2. Legislation was the premise of the retrofit project
　3.3. Technique standards provided the direction for retrofit project
　3.4. Multi-channel financing models were encouraged to be explored
　　3.4.1. Local government leading model
　　3.4.2. Property corporation leading model
　　3.4.3. Energy service company (ESCO) leading model
　　3.4.4. heating enterprises leading model
　3.5. Rewarding measures clarified the rules of retrofit project
4. Main problems
　4.1. The retrofit plan for assignments should be modified
　4.2. The economic obstacle still existed
　4.3. Incomprehension of retrofit content caused unreasonable retrofit schemes
　4.4. The heat metering reform struggled
　4.5. Reward on energy efficiency by metering did not realize
5. Future suggestions
　5.1. Management
　5.2. Target and assignments
　5.3. Promotion of energy contract management (ECM)
　5.4. The warm-house retrofit pattern
　5.5. The carbon-exchanging model
　5.6. Establishment of the mechanism of rewarding on energy efficiency by metering
6. Conclusion
Acknowledgments
References