gbXML

gbXML, or Green Building XML, is an open, XML-based schema designed to facilitate the transfer of building geometry, zone data, and system information from BIM and CAD models to energy and daylight analysis tools. It aims to streamline building performance analysis by providing a common data representation that can be consumed by multiple software packages.

The schema covers building geometry (spaces, zones, bounding surfaces), construction materials and assemblies, loads and HVAC equipment, and references to weather data. By exporting from tools such as Autodesk Revit, ArchiCAD, or SketchUp, and importing into energy analysis engines like EnergyPlus, TRACE, IES VE, or OpenStudio, users can run simulations without re-entering data.

gbXML is maintained by gbXML.org as an open standard intended to be extended as needed. While widely supported by many energy modeling tools, coverage of features can vary by software, and accurate results depend on correct mapping of model elements to gbXML concepts.

gbXML complements other standards such as IFC; it is not a building energy engine itself but a data exchange format. It remains a common choice for early-stage building performance assessments and for code compliance workflows that require interoperable data transfer between BIM and energy modeling tools.