
With any complicated subject I have to establish an anchor point before I can start mapping everything in its place. Those long verticals of the door frame that I started with on the left weren’t much help and it was only when I established the leaded window above the door that I was able to get a grip on proportions. The 45° pattern made a useful grid.
You can see where this went slightly wrong as the window started going into perspective on the right, my drawing equivalent to the distortions you’d get if you were photographing the scene with a wide-angle lens.