Estimating the energy-saving potential in national building stocks - A methodology review

Building stock models, sometimes referred to as urban building energy models (UBEM), are frequently used for estimating the energy-saving potential in the building stock. It is essential that these models provide reliable results in a transparent way, since these models are often used for guiding political decision-makers. The aim of this paper is to identify key elements in building stock modelling by reviewing state-of-the-art literature. Furthermore, focus is on pointing out pivotal aspects that are not considered in the present building stock models. Most of the models reviewed here make use of representative buildings. However, none of the studies addresses the question of what makes a building representative. Likewise, only few of the studies address the validity of the proposed model. Moreover, two critical aspects were found left unaccounted for in the present models: Firstly, the supply-side of the system is not considered in most of the models. Secondly, the energy-saving potential is calculated solely based on building characteristics, ignoring systematic discrepancies between the calculated energy demand and the actual energy consumption in subsets of the building stock. Both aspects turn out to affect the estimated energy-saving potential substantially, when included in the models. Aim: Identify characteristics of building stock models that are essential for determining the energy-saving potential in national building stocks accurately, in a transparent way. Scope: Models dealing with energy consumption on a building stock level Conclusion: 1) The representativeness of the proposed representative buildings should be addressed; so should the validity of the proposed model, 2) energy demands in buildings must be considered in a system perspective and finally 3) systematic user-behaviour trends must be accounted for to ensure valid results.