As a company moves into using Autodesk Revit for the design of buildings, they quickly learn that families are an important part of the process. Families represent entities within a project, such as walls, doors, windows, furniture, water heaters, drains, sinks, condensers, air terminals, receptacles, electrical panels, light fixtures, etc. Revit provides many families with the software installation, but there are never enough or they never look or function the way that the Revit user’s organization desires. As a result, custom Revit families are created for use within their organization.
Unfortunately, many organizations utilize inappropriate people to create these custom families.
Organizations often look at the process of creating a Revit family similar to creating an AutoCAD block and don’t fully realize the level of knowledge that is required to create quality Revit families. It is more than being a great detailer and being able to accurately model the intricate details of the item. The modeler needs to understand the impact of what they model and how to effectively model it. It is important that they understand how the family will actually be utilized by the end user in a project.
The visual 3D Model and the Data within the model are a couple important aspects to the family that need serious understanding. Following are some items that need to be understood by the family creator and taken into consideration within the family.
- All aspects of Level of Detail.
- How much information needs to be modeled?
- How much detail is actually shown in 3D components (grooves, ridges, grids, etc). Threads do NOT need modeled!
- Using the different Coarse, Medium, Fine detail levels to an advantage and not show everything all the time.
- Impact of modeling various sizes of components and when to model or not model something.
- When to model radiuses and chamfers on components.
- What should be created as 3D components versus drawn with Model lines or Symbolic lines?
- Impact of showing modeled elements in a view versus showing information as Model lines or Symbolic lines.
- When Reference Planes and Reference Lines should be used and the difference between them.
- Purposes of the various “IsReference” parameter options for Reference Planes.
- Various effects and capabilities of using nested families.
- Impact of using various hosting types, such as “face based”, “ceiling based”, “floor based”, “wall based”, “roof based”, “line based”, or not using a hosted family at all.
- Impact on using the “Shared” parameter (a Yes/No function and not a Shared Parameter) feature of a family.
- Using Masking Regions to control visibility of information in a view and opposing views.
- Controlling Annotation Symbols as nested families.
- Impact of utilizing Subcategories
- Importance of parameter naming.
- Impact of Shared Parameters.
- When to use dimension parameters that can be modified versus creating actual dimensions.
- Impact of using Type versus Instance parameters, including impact with nested families.
- How the Formula portion of parameters impacts data in ways other than just a calculation.
- Restricting values that can be entered into a parameter.
- Controlling data in nested families.
- Type Catalog creation and usage.
- How placement of MEP connectors varies by how 3D components are created.
- Various ways that parameters control MEP connector values.
- Linking MEP connectors.
- Primary Connector features.
The above list does not cover all aspects of creating quality families, but having a good understanding of the above items help the family creator understand the ramifications of how they create the family. Future users of the family will be thankful for the creator’s understanding of the process.