Subtract inner shape when forming shape

I have created the following shape.

When deleting an edge, the top face is also deleted as expected.

When I draw that line again, Sketch Up creates a face using the outer shape without taking into account the inner one.

It’s not possible to select the area formed inside the inner shape. The only way to go back to the original model is to redraw one of the lines of the inner shape (so that a face is formed) and then I can delete it.

Is this the normal way to achieve this?

Pretty much.

There are several way, none of which are that complex. Here is intersect, and an added tip, Orient Faces so you only see white. The blue/gray ones should be inside.

Triple clicking does not select the inner shape in my case. Any idea why? I can select the whole model though and use “intersect with faces” as you did.

Sometimes this happens. The vagaries of edge and face intersection have plagued SU users from the beginning and will no doubt last many years. You will find situations were the face should be cut by the edge, but no matter what you do it won’t. I have no answer. And I ask the question every time I get the chance.

There is a consistancy here. It seems that SketchUp isn’t aware of a missing face inside the loop that you recreate by redrawing the outer edge, the one that you just deleted. It just creates the large face overall.

If there are already coplanar faces inside the newly created loop and larger face, then SketchUp intersects the larger face and the coplanar smaller face automatically.
SketchUp just won’t create a larger face and only then (subsequently) intersects geometry to split a new face area into several faces. See below: