I selected this tiny part to get started in Worldographer. I figured each square was 10 feet across. These structures are massive.
And then found I didn't have the right icons. Plus, the icons available don't seem to match the style. Well, Worldographer has standards to make your own icons. So off we go to painting with GNU Image Manipulation Program.
This is one of those viking type longboat houses. I only need one because the software will let me rotate and scale as needed. It's rough, but coming along.