How well do building energy performance certificates predict heat loss?

This paper evaluates the predictive power of building energy performance certificates on ex-post home heat loss. Improving the insulative capacity of residential properties is a policy priority in many markets, with building energy performance certificates providing the indicative benchmark. We exploit a rich panel dataset of high-frequency thermostat readings, coupled with data detailing weather and buildings characteristics, to identify an ex-post metric of heat loss. Our results show a significant effect of building energy performance rating on indoor temperature, a proxy for home heat loss. However, we do not find evidence of a distinct gradient in performance between building energy rating categories, as suggested by ex-ante estimates of home heat loss.