I've used EasyCad (available from FastCad for about £300, or trial download)
for a few things. It's a 2-dimensional drawing package, like a baby-brother
of AutoCad which costs several £000).
Not 3D, but fantastic for scale drawings, layers, colours,
tiled-over-many-page print, work in cm/inch on same drawing.
I did think it could be used for a house extension - layers for ground,
foundations, electric, walls, etc.
(main reason was we have it at work, so it's free for me)
just a thought.
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