Can't cut open window and door

Hi, so trying Sketchup, so far so good. But here comes the trouble - I cannot open two holes (one for the window and one for the door). All other openings around done without a problem, the object is not grouped, noir it’s curved. Can someone please pinpoint the problem that keeps me at stand still?t1.skp (1.1 MB)

I push-pulled one of the windows through to the thickness of the top of the wall, and this is what I see on the inside. Those strange lines that vanish into the wall are a sure sign that the inner and outer wall surfaces are not parallel!

The X values should all be the same. They aren’t because your rectangle for the openiing is drawn not only off plane but off axis.

You would find it easier to model precisely if you turn off Length Snapping in Model Info.

You should also be correcting reversed faces as you go. There should be no exposed blue back faces in your model.

Thanks for the quick replies guys. Have a wonderful Xmas!

Another potential issue: as @DaveR’s text labels show, the coordinate values in your model are very strange and seemingly arbitrary. I think you will benefit from learning to input precise values as you go (just let go of the mouse and type the desired value). I seriously doubt all those trailing decimals have any validity, and even the whole mm values are peculiar!