Hi.
Model it as you would build it. It depends on the type of structure you'll use to build it.
For example, if you'll use a concrete slab as main structure, then use a composite that only has concrete as core and create the slab to its whole extent. Then create composites for the different finishes with their corresponding composite layers and thickness. Take advantage of the fact that AC lets you create composites without a core skin and that you can use the bottom reference plane for these finish slabs. You won't need to use SEO if you set this up correctly and have correct building material intersection priorities assigned.
This has several advantages:
* Should you export to IFC, you'll only have one structural slab instead of a lot of little core pieces of slabs that form the main slab.
* You don't need SEO.
* Priority Based Connections should take care of intersections with walls if several adjacent areas have the same finish.
* You have a great deal of control options for these elements and documenting their properties.
* Changes to main structure or finishes are easier to handle, for example, change the main slab thickness once instead of doing it inside each composite structure with different finish.
On the downside, you have to keep track of more elements... but that's the way it happens en real life anyway.
Hope it is a bit clear.
Best regards.
