[the invisib1e hand]

IMHO - and I realise this doesn’t answer your questions directly — If you do not know how to use, or do not want to teach yourself to use, Autocad, then hire an architect. Rhino-3D is also extremely user friendly, thought not geared specifically for home design.

[Yosemitest]

When I was in the military, I knew one day I would move back home, where I grew up.
I THOUGHT that I'd work on a house design while I was in the military, a little at a time.
BUT, I never got around to it. Hence, I didn't learn how to use my program.
Now, I'm older and have acquired items, say speakers that need a minimum distance from the TV, and I want to plan a good layout for a home, and play with the plan.
Then when I'm satisfied with the layout, I'll start construction.

I guess there's always the pencil and paper method.