With mesh it gives that
sand dune using mesh.gh (18.6 KB)
A version using offset from clipper so 3 types of roofs
http://www.food4rhino.com/app/clipper-grasshopper
sand dune using clipper v2.gh (26.7 KB)
With mesh it gives that
A version using offset from clipper so 3 types of roofs
http://www.food4rhino.com/app/clipper-grasshopper