Quality and accuracy of digital twin models for the neighbourhood level building energy performance calculations

Abstract

For scaling renovation, there is a need for assessing the energy performance of buildings at the neighborhood level. Traditional methods for assessing individual buildings are manual and time-consuming – not sufficient to enable the neighborhood level assessment of the energy performance of buildings. Instead, new methods based on existing data in national registries and building typologies are required. The aim in this article is to develop for obtaining necessary initial building geometry information for energy performance calculations from the Estonian national Building Registry (EBR), including also Digital Twin (LOD) geometric models of buildings, and the quality and accuracy of this data is assessed. Altogether 417 representative buildings were used for qualitative and quantitative analysis. A sub-sample of 41 buildings were selected for more detailed analysis and development of methods. Two methods were developed to extract and enrich initial building geometry information for energy performance calculations: (a) the method combining the EBR and building reference data; and (b) the method combining the EBR and building typology data and LOD models of apartment buildings. The estimated accuracy of the first method (a) is around 98% and the second method (b) around 94%. Both methods underestimate the actual envelope area and thermal bridge lengths.