Family Performance Tab
The Family Performance tab helps identify families that may require attention for performance or model management reasons.
Column 1 – Inst
The number of instances of this family used in the model.
Use this as an indicator of whether it is worthwhile to spend time improving the family.
Column 2 – Faces
The number of faces in the geometry.
A high face count is often a sign that a family may need optimization.
Why it matters: Every view interaction forces Revit to compute the geometry. The more geometry, the slower the response.
Rule of thumb: Few solids with many faces is usually problematic.
Column 3 – Solids
The number of solids in the family.
Like faces, this helps identify families worth reviewing.
Why it matters: Each solid contributes to geometry calculations. The more solids, the slower Revit responds.
Rule of thumb: Many solids with few faces is usually problematic.
Column 4 – Sub no
The number of solids without an assigned subcategory.
While subcategories do not directly improve performance, they allow users to control visibility more effectively. Families with proper subcategory assignments give users finer control over view performance.
Column 5 – Sub yes
The number of solids with an assigned subcategory.
Column 6 – Not 4
The number of solids not visible in all four detail levels (Undefined, Coarse, Medium, Fine).
Ideally, this number should be close to the total number of solids (Column 3).
Column 7 – All 4
The number of solids visible in all detail levels (Undefined, Coarse, Medium, Fine).
Ideally, this number should be as close to zero as possible.
Column 8 – Undefined
The number of solids visible in the Undefined detail level.
This is an API-related value and can generally be ignored.
Column 9 – Coarse
The number of solids visible at the Coarse detail level.
Column 10 – Medium
The number of solids visible at the Medium detail level.
Column 11 – Fine
The number of solids visible at the Fine detail level.
Column 12 – Tax
A calculated value: faces × instances.
This indicates which families are most likely to deliver performance gains if optimized.
Tip: Do not waste time optimizing families with only a few instances, even if they are heavy. Focus on families that occur frequently.