Tuesday, August 15, 2017

gbXML Certification and Validation

Autodesk is helping to define a new, more accurate, gbXML schema to improve the way industry is documenting and sharing data; specifically: geometry descriptions, envelope descriptions, schedules and systems.
"gbXML is an industry supported schema for sharing building information between disparate building design software tools."

As a "research partner" with gbXML, Autodesk is helping define the Level 3 compliance requirements and compliance tests.

This standard and validation process...
will give gbXML Authors (e.g. Revit) and Consumers (e.g. You) a higher level of confidence in the data. I was in a presentation recently in Toronto, Canada, at BILT North America, I listened to a mechanical engineer present and voice his concern over the quality of gbXML from various Authors.

A few examples; Level 2 tests checks for the accuracy of spaces, such as a simple gable roof. Level 3 verifies below grade walls are defined relative to a slab on grade and can include things a sloped floors and bottom of walls.

I recently did a series of posts which highlight the way Revit automates the creation of the energy model, which is in the spirit of Level 3 compliance:


The next three images show how Revit is able to divide the roof and floor so the balcony is a shade surface, same for the top of the wall, which defines the parapet. Also, note the sloped floor, plus "slab on grade" versus "interior floor". 
Typical Revit model

Section; floor and roof extend outside of building + sloped floor

Energy model filter to floors an shade surfaces

Authoring tools that pass certification will be listed here on the gbXML website: http://gbxml.org/Software_Tools_that_Support_GreenBuildingXML_gbXML. Currently, the only certified software is Open Studio at Level 2. Autodesk should be listed as "In Progress" for Level 3.

For a great overview of all of this, I encourage you to watch this recorded webinar by gbXML and my friend Ian Molloy from Autodesk; Click here to watch the recording.