Hygrothermal simulations such as WUFI are coming into increasingly common use among building science researchers and practitioners, architects and designers, and energy analysts. Such simulations have been shown to be powerful and validated tools. However, with increasing dissemination of these types of modeling tools–most notable WUFI–less-experienced or less-informed practitioners have run models that provide unrealistic results (typically overly conservative). In some cases, these results clearly contradict extensive field experience and known history of assemblies, showing failure when they do not occur in reality. In other more worrisome cases, models run on assemblies that clearly have not performed historically show successful performance. This has resulted in confusion in the building industry—specifically, problems with advancing knowledge of moisture-safe building enclosure/shell assemblies.
Therefore, Building Science Corporation led a Building America Expert Meeting on “Guidance on Modeling Enclosure Design for Above-Grade Walls.” Presenters from national laboratories, consulting firms, and building material manufacturers presented on their research, which matched field measurements of wall hygrothermal behavior to simulations. This was followed by a group discussion on various topics, including required expertise for running WUFI, education requirements, and the need for material property testing.