yes,
a tile is a compilation of up to 3 walls and a piece of the floor. (or just floor for center room tiles). every corner, every straight wall and every floor and roof plate is a single entity
later, there will be 5 types of each tile, each one with a different roof formation, to get this wavely look of the DK2 room tops.

and i want to use complete rooms for different situations.
like: instead of using 8x5 tiles for a library, i create a single model room with the same size (to save entity memory)