I need help putting a floor into this twisted home

Hi there i’m trying to put a floor into my house project, but i am having difficulties doing so. If someone knows the solution please help

tiny house.3dm (376.7 KB)

Welcome @e.guenov.e,

Your house is flooded!? :wink:
Where do you want to introduce the floor slab? Underwater or above? :smiley:
Just kidding!

If I had to guess, I’d say that the issue is that your “facade” is composed of individual mesh faces and now you probably try to trim the blue surface with it, which won’t work for whatever reason.

Honestly, I’d remodel the whole thing as a closed brep/polysurface! Since, it’s such a simple model and you already have a base mesh, this should be pretty straightforward and quick.