U.S. General Services Administration
BIM Technical Standards: Parametric Components
Parametric components are dynamically changed instance-based objects. They go by different names in different BIM platforms. These standards are applicable to all forms of these objects. This includes Revit families, AutoCAD components/dynamic blocks, Bentley building parts and families and all similar types of data from all platforms.
Graphical information of components will be required to adjust based on Level of Detail (LOD). As the design progresses, so will the detail level of the graphical information. Common representations are a representation for LOD 100-200 (course detail), LOD 300 (medium detail), and LOD 400-500 (fine detail).
Information (metadata) is an important aspect of this type of object. It is very important that parametric components contain information relevant to the component and to the project. Level of Detail will dictate the amount and type of information required. See Minimum Attribute Standards for more information on this topic. Design components used to generate the virtual model must be associated with an Omniclass Number and Omniclass Title. This allows for organization and understanding of design intent. This effort occurs in all design and construction phases. Within a Revit environment, it can be addressed in the family. The family templates generated by the GSA have this information already, however, if the predetermined information is not accurate to the component, it is the responsibility of either AE or GC (based on LOD) to be corrected.
Standard
- The priority of standards for the creation of parametric components is as follows: GSA National BIM Guidelines → Region 5 Supplemental Standards → BIM Software Vendor Standards → any in-house parametric component guidelines or standards.
- If an industry or software vendor standard exists for the creation of parametric components, you are expected to follow it. For example, if the project is using Autodesk Revit, the Revit Model Content Style Guide should be used.
Naming of Parametric Components
Given that parametric components are such a critical part of any BIM, it is necessary to have some level of consistency in the naming of the components. The following rules should be followed when naming parametric components:
| Good Naming | Poor Naming |
|---|---|
| Exterior - Marble Paneled - 30 3/4" | EXT-Sht-CMU-8" |
| Concrete Ceiling - 1 1/2" | New system |
| Curtain Wall H Mullion Level | CUSTOM - 1 |
Provided Revit Families
The GSA Region 5 BIM Templates do not require the use of any special Revit Families for proper use, however, a number of Families are provided. These Families were developed by GSA Region 3 and are provided for GSA teams to deploy on their projects. These Families are provided "As-Is" and are not required. The Families can be downloaded from the Downloads Section of the site.