Thanks all, it's been fun to do.
Originally I intended to do a double long greenhouse. I had one so I bought parts for a second from DS, but they were out of the roof. So what to do with extra walls and no roof but go up? Once I had the idea I really liked it and I think it worked out well.
There will be a general tour of the castle coming up in a while (once I get done snowing on the rest of the roof). Maybe another story as well, it depends on time as always.