Building geometry data from online maps for accurate thermal simulations of districts

Abstract

Current approaches for simulating the energy performance of buildings on a large scale are limited by numerous assumptions and simplifications, which can lead to inaccurate estimations. While new tools and procedures are emerging to improve accuracy, there remains a need for more user-friendly methods. This study proposes a new tool based on online maps to create the geometry of districts in a simple way. The tool also enables an automatic evaluation of all buildings through dynamic hourly simulations, using a building simulation software and allowing to consider different weather conditions. To illustrate the procedure, a district at risk of energy poverty in Seville (Spain) is modeled, where hourly temperature data for a whole year are available to demonstrate the need for building improvements. The tool is used to evaluate the energy demands of the district under several retrofitting alternatives, and free-floating simulations are also performed to evaluate the improvement of thermal comfort without air-conditioning systems. The aim is not to discuss the actual values for this particular case, but rather to identify the correct direction for large-scale studies, so as to make them more easily conducted. Overall, it may be concluded that the results provided by comprehensive tools, such as the one proposed in this study, enable easy yet accurate evaluations of buildings on a large scale with significant time savings, as well as the identification of locations where retrofitting interventions would have the greatest impact.