Beyond the bioclimatic chart: An automated simulation-based method for the assessment of natural ventilation and passive design potential

• Lack of detailed instruction on bioclimatic charts leads to misuse. • Higher internal gains reduce correlation between BEM and the bioclimatic chart. • The bioclimatic chart is not a trustworthy design method. • BEM-based approaches are preferred to assess passive design potential. • An automated user-friendly BEM tool is proposed for educational and early stage use. Ubiquitous use of active heating and cooling technologies facilitate occupant comfort in virtually any location while increasing building-related carbon emissions and displacing climate-responsive design strategies. The effectiveness of the latter depend on climate and building program and many design teams struggle to evaluate passive design potential during schematic design. To support the process, we investigate and compare two alternative methods, the bioclimatic chart and building energy modeling (BEM). While BEM is more accurate, it is more complex to use and time-consuming to learn and implement. A comparison between predicted overheating hours for various passive design strategies and building uses in a variety of climates reveals some important differences. A broad range of correlation, with R² values ranging from 19% to 81%, is shown. Higher correlations are linked to building usages with lower internal heat loads. Furthermore, the bioclimatic chart fails to identify the need for an A/C system in 10% of the 302 cases where simulations indicate it is necessary. Given these inaccuracies, we suggest that bioclimatic chart is not a trustworthy design method and instead advocate for a BEM-based approach. To overcome the complexities and time-consuming aspects of traditional BEM, an automated BEM-based tool called ECOmpass is introduced. This prototype provides actionable design advice for a given climate and building usage at the click of a button.