I have been granted planning permission for an outside staircase which will provide access from my kitchen to the garden below. The permission has been granted for a 4 ft wide platform which is the same width as the doors. As it means the doors will open out directly on to the staircase railing. I want to increase the width of the platform to 5 ft. If I go ahead and do this without getting more permission what will happen if it is noticed on inspection?