The thermal performance gap in buildings is defined as the difference between the theoretical and the actual energy consumption for heating, and is known to undermine energy retrofit strategies and policies. This study examines the performance gap in retrofitted buildings using the Swiss Cantonal Energy Certificate for Buildings (CECB) database, using a sample of 1172 buildings for which both theoretical and actual metered consumption were known. We found an average negative performance gap of –23% for pre-retrofit buildings (actual consumption smaller than calculated) and instead a good approximation of actual consumption with theoretical consumption after retrofitting (a positive gap of 2%). A regression analysis on the energy performance certificate input parameters characterizing the building led to the conclusion that these are poor predictors of actual consumption compared to the theoretical calculation: parameters such as the energy label and the thermal proprieties of the envelope (U-values) have minor explanatory power for the actual consumption despite explaining a high degree of change in the theoretical consumption. Analysis of the indicator Energy Savings Deficit (ESD) shows an overestimation (of 37%) of the achievable savings on the basis of the theoretical consumption, whereas the prediction of savings using measured consumption before retrofit resulted in a good agreement with the actual savings (3.6% overestimation). This implies that energy savings can be estimated rather accurately by comparing the actual current consumption with the expected theoretical consumption defined by the certificate after retrofit.

建筑物中的热性能差距定义为供暖的理论能耗与实际能耗之间的差，已知会破坏能耗改造策略和政策。这项研究使用瑞士州建筑节能证书（CECB）数据库，对1172栋已知理论和实际计量消耗的建筑物进行了抽样调查，研究了翻新建筑物的性能差距。我们发现翻新前建筑物的平均负性能差距为–23％（实际消耗量小于计算值），而翻新后的实际消耗量与理论消耗量之间的近似值很好（正偏差为2％）。对表征建筑物的能源绩效证书输入参数进行的回归分析得出的结论是，与理论计算相比，这些参数对实际消耗量的预测较差：诸如能源标签和围护结构的热特性（U值）等参数具有尽管解释了理论消费量的高度变化，但对实际消费量的解释力较小。对指标能源节约赤字（ESD）的分析显示，根据理论消耗量，可实现的节省量被高估了（37％），而在改造之前使用测量的消耗量进行的节省预测与实际节省量有很好的一致性（高估3.6％）。