Components, Families, and Annotation
This domain is about families: system families (walls, floors, ducts), loadable families (doors, furniture, casework), and in-place families. Loadable families can be component-based or annotation-based (tags, symbols). Understand the three family editors: the Family Editor for loadable families, the conceptual massing environment, and the project environment for system families.
Know reference planes, parameters, and constraints. A well-built family is parametric: reference planes are named and locked, dimensions drive parameters, and geometry is locked to reference planes. Type vs. instance parameters again matter here. Shared parameters live in a separate text file and are required to tag or schedule a value across families.
Annotation traps: tags read parameters from the element; a tag showing "?" means the parameter is empty or the wrong tag category was used. Dimensions can be temporary (visible on selection) or permanent (placed). Text and keynotes are different tools. Detail lines are view-specific and do not appear in 3D.
Rule of thumb: if a value needs to appear in a schedule and a tag in multiple families, it must be a shared parameter defined identically in each family.
Worked example: a door tag shows "?" in a plan. The tag is placed, but the Mark parameter on that door instance is blank, or a different tag family was loaded that references a parameter the door does not have.