Working With a Small and Predictable Performance Gap

Abstract

Much is written about the performance gap. Multi- ple studies show alarming discrepancies between de- sign and actual building energy performance. Should this prove to be a universal truth, the need of more detailed dynamic modeling methods can certainly be put into question. The prevalence, of somewhat an- tiquated, monthly methods in many current building codes seem to support this view. In this paper we demonstrate a case supporting the opposite viewpoint. When the motivation and tools are right, su_cient accuracy between prediction and actual energy performance can be achieved. We present a building modelling case, where appropri- ate data was collected over a period of a full year for an o_ce building with gross oor area of 31,809 meter squared in Stockholm, Sweden. We showcase how by abiding by a Keep it Simple and Straight- forward approach in modeling one is able to achieve accurate energy performance predictions without sac- ri_cing on capturing building's dynamics and internal states. However the selected project is not a singu- larity, but represent the mainstream in state of the art Swedish design practice. We end by highlighting some pitfalls with current guidelines regarding cal- culating goodness of _t measures between empirical data and a dynamic simulation model, and providing some recommendations for more appropriate metrics.