In effect yes, not sure what my builder is going to do exactly but it will be built as per the diagram above. He did mention making wooden formers to support the concrete. Anyway, I am meeting him on site tomorrow to mark out the site, founds being dug on Tuesday and concrete strips being poured soon after, so after a two and a half year battle we finally are getting started. We just have to wait for our Secretary of State appeal to find if the top floor is cottage ( as we want) or room in roof that the LPA are insisting on.