NOTE: The book recommends making the slots shown here to accomodate the fastbuild door frame. Mark recommends cutting slots in the frame itself. Were we to do it again, we would have done theslots in the frame. It is easier to install and take out during the fitting process and it also leaves the tree support webs much more structurally intact. Arguably, this is to the good. It certainly is less of an eyesore!!:-)