What instances is Create parts not available (greyed out)? Have experimented with out of the box families but then following duplicate-edit of types then create parts greyed out. So take a wall-floor-roof simple assembly, the wall is a modifed type but loaded through the template, the floor is generic and the roof is a family-type-duplicate and edit. If I change it back to out of the box generic its still greyed. Have then tried the same exercise in a new project again making a duplicate-edit family type and cannot repeate the create parts tab unavailable.
The roof modeled as default slope to all faces (pick walls) is not available. Model as a mono by picking walls and setting only one side as defines slope seems to work. But form the roof with all sides define slope and them edit footprint to uncheck defines slope (same result) create parts is greyed again.
There a rule here somewhere! Is it the element must be with all settings when formed and not changed by edit footprint etc
Parts should be able to be generated from elements with layered structures, such as:
1. Walls (excluding stacked walls and curtain walls)
2. Floors (excluding shape-edited floors)
3. Roofs (excluding those with ridge lines)
5. Structural slab foundations
Some additional information below:
As Mr. Duell stated, Stacked Walls cannot be parted out. Also, walls with Sweeps do not properly translate into Navis. So is there a workaround for Stacked Walls with Sweeps to show properly within Navisworks?