[2023] Cosmetic Buildings skins only or layout as well?

Hi I have a question about the cosmetic buildings are they simply building skins or do they also change the interior of the building to make the floorplan match/make sense. It doesn't appear as though the cosmetics follow a standard floorplan/layout with all entrances matching, which is why I'm asking. an additional question for example would be the Royal Featherstone Wearhouse featured in the current cosmetic pack features a tower. Will there be a way to ascend the tower if you use this cosmetic or will it be inaccessible? Assuming the building it's applied to doesn't have a tower that maps onto 1:1.

If it is simply skins with no interior modification, is there work being done to ensure the skins being developed match the standard floorplans for the buildings they are intended for?
Thank you