There are many small errors in your model. For example, notice the small gap at the left and the weird corner at the right in the screenshot below. I suggest you zoom in closely to examine the borders of the various rooms that aren’t forming faces and look for these kinds of issues.
In addition, your model shows that you need to read up more about SketchUp’s Layers, as you aren’t using them safely. SketchUp’s layers only control visibility and coloring, they do not isolate or separate edges and faces from each other. Edges and faces that are hidden or associated with non-visible layers will still interact with visible edges and faces, typically causing very confusing effects! So, all edges and faces should be drawn and left associated with Layer0. Create Groups or Components and associate them with other Layers if you need to simultaneously isolate edges and faces and control visibility.