Computational geometry in the context of building information modeling

Building energy analysis has gained attention in recent years, as awareness for energy efficiency is rising in order to reduce greenhouse gas emissions. At the same time, the building information modeling paradigm is aiming to develop comprehensive digital representations of building characteristics based on semantic 3D models. Most of the data required for energy performance calculation can be found in such models; however, extracting the relevant data is not a trivial problem. This article presents an algorithm to prepare input data for energy analysis based on building information models. The crucial aspect is geometric simplification according to semantic constraints: the building element geometries are reduced to a set of surfaces representing the thermal shell as well as the internal boundaries. These boundary parts are then associated with material layers and thermally relevant data. The presented approach, previously discussed at the International Academic Conference on Places and Technologies (Ladenhauf et al., 2014), significantly reduces the needed time for energy analysis.