non-tech bSDD FAQ`s

Following up on the excellent General Assembly of IFC Implementer`s meeting this week (9.6-9.8.21) I would like to start a topic regarding non-technical questions for the bSDD. I hope this might be the start of a FAQ resource for working with the bSDD and possibly transform into an external URL as a resource for improving stakeholder competence.

My following questions are regarding best practices for extending IFC with the bSDD. This discussion could also be a place to discuss best practices for many of the other bSDD capabilities (e.g model checking, checking regulation compliance, etc.)


  1. Are there any standard practices described somewhere for how to extend IFC with local standard content (with homemade standard Psets)
  • Should the international classification code be available as a property? it should absolutely also be hidden in the IfcClassificationReference but for international interpretation such a code would be different depending on the country.
  1. Where is it stated as correct to use a material property in the bSDD ? do we just make it more complicated when we use IfcMaterialReference or are both ways correct?

  2. Given that the bSDD 2.0 only provides an IFC domain for 4.3. Can users extend their IFC 2x3 MVD exports with the IFC 4.3 schema? Is this best practice or is it suggested to address such questions on an individual basis?