I must have accidentally moved my geometry because I now can’t draw a floor and the shower wall with the niche on also no longer has a face. I can’t seem to work out what’s happened.
Your model is kind of a mess. You’ve got a bunch of weird geometry, some of it hidden, which would prevent a floor face from being formed. Zoom in close to the bottoms of the walls where the door and show is. Lots of edges running next to each other. They look thick in the screenshot because there’s so many and they are close together.
You could clean all that up but the walls are simple enough, I think the easier approace would be to delete the walls and start over. I would model the floor with a bit of thickness and group that geometry first. Then I would model the walls on top of that and group that geometry separate from the floor. If you need a ceiling, model it and group that geometry separate from the walls.
I did my standard cleanup procedure on your model. I fixed incorrect tag usage,
I think the stray geometry came about when I was mapping out my tiles. For some reason i can’t see this hidden geometry like it’s showing up on yours, do i need to change my settings?
I turned on Hidden Geometry in the View menu and then triple clicked on the walls to select all connected geometry. After that I right clicked on it and chose Unhide.