Now that I've got my centre point, I can now mark out the inside edge of the dome on the base. This will provide me with the guide for laying my first course of bricks.
Once the dome has been marked, it's time to position the door. Again I've used patio tube for the frame. This door frame has been made to suit the door that I will be using. It's off an old Metters stove. It's a bit smaller than I would like, but it'll do the job, and should look pretty good.