Carmel Software recently announced that it has received funding from the National Renewable Energy Laboratory (NREL) for Phase III of improving the Green Building XML (gbXML) interoperability schema that allows various BIM authoring and analysis software tools to integrate with one another. Here is a more layman’s explanation of what this all means:
Green Building XML (gbXML) is a schema or “language” that allows BIM (building information modeling) authoring software tools such as Autodesk Revit to communicate with building analysis tools such as Trane TRACE. For example, a user is able to design a 3D virtual model of a building in Autodesk Revit. This model includes complete visual geometry of the building and information about the types of walls, windows, roofs, lighting and occupancy density. Since this information is required by building energy analysis software tools, it is redundant to re-enter all of it into a stand-alone energy analysis software tool when it is readily available from the 3D model. This is where gbXML helps: A software tool such as Autodesk Revit is able to “Save As” gbXML meaning that it is able to export all of its geometry and other building information into the gbXML language format. Taking this gbXML file, the user is now able to “import” this building information into software tools such as EnergyPlus or Trane Trace without manually re-entering all of this data by hand. The end result of all of this is that an energy modeler is better able to design more energy efficient buildings for purposes of, say, LEED certification.
In theory, the above workflow sounds seamless and attractive to anyone involved with modeling the energy usage of a building. In reality, the process is fraught with enough complications that energy modelers often forego this process in favor of more manual methods. These complications result from inconsistencies in how the various software tools integrate with gbXML. Therefore, the NREL has agreed to fund Carmel Software to develop methods and “test cases” that allow these vendors to test their gbXML integration and ensure they are importing and exporting valid gbXML models.
Phase III of this effort begins this month, and it will certify NREL’s OpenStudio software (an open source tool for performing energy analysis) against the gbXML validation procedure developed in previous phases. In addition, the gbXML web validator that was initially developed in Phase II to allow software vendors to test their gbXML files against the use cases will be further developed to validate any gbXML file. This new “generic” validator will also display an interactive 3D representation of the model in any web browser.
“This is the type of support and infusion we need to propel gbXML into the next phase of building design and analysis, ” says Stephen Roth, Principal of Carmel and President of the Board of Directors of gbXML.
For more information on gbXML, goto