A newer answer to this question can be found at Upgrade existing elements and their properties to the current Catalog Schema.
I have older Family and Part definitions from a previous dataset to take into AECOsim Building Designer. How can they be used in this product?
Users of Architectural Building Designer, Mechanical Building Designer, and Structural Building Designer may have customized their datasets for many reasons including:
The need to change datagroup catalog item property values.
The need to add new catalog items to datagroup catalogs.
The need to create new datagroup catalogs.
The need to add datagroup definition files.
The need to create additional fixed and parametric cells.
Use the "Dataset Upgrade Utility" in the Utilities pull down menu to upgrade your Families and Parts. This utility upgrades customized datasets to be compliant with Building Designer schema revisions, as best as possible.