This is a model my son made of Lenzburg Castle for a school project.
(see https://en.wikipedia.org/wiki/Lenzburg_Castle )
Initially he/we found the plan view of the Castle on the web and downloaded that. Then using Inkscape we drew round all the buildings to make 2D objects. This could then be saved as a .svg file which could be imported into AUTODESK 123Design and extruded up to give the buildings height (looking at aerial photos for comparison). Finally the rooves were added.
