Hi,
I have developed a flower box for my dormer window. The shape of the box is designed to fit perfectly on my roof. I used two-component glue to assemble the parts. If you need special modules (left/right end, half middle parts), you can simply insert the wall module in the slicer wherever you want it. I also integrated holes for water drainage. Attaching the flower box to the roof is up to you. I have a metal sheet on my dormer window to which I could screw for mounting. Have fun and happy printing! :D