How do I customize a door family (panel, frame, materials)?

Select the placed door and hit Edit Family to open it in the Family Editor. The dimensions live in Family Types (Create tab) — they’re parameter-driven, so change values there rather than dragging geometry. Edit the panel/frame solids with Edit Extrusion/Edit Sweep, keeping sketches locked to the reference planes, and after EVERY geometry edit open Family Types and flex the parameters — an un-flexed family fails silently months later. For materials, use Associate Family Parameter on the material value so it becomes a type parameter. Then Load into Project and overwrite, and save your own .rfa copy. Full steps: Edit door family →