I want to put a door through to the garage in my kitchen. The gap where it could go is quite small and would involve the door frame being only 10cm away from an internal corner, which forms an external corner on the outer wall. I read that there is a regulation regarding the proximity of new doors/windows to an external corner (660mm?), however in my case the corner is to a flat-roofed single storey extension, so there would only be a height of about 4 bricks above the door lintel. Do structural regulations apply in this circumstance, where so little weight is being supported?