[deermealec]

Blender

Looks most impressive but would there be a rather steep learning curve to cope with? (OP asked for something basic, and that's what I'm after too). Free version of Sketch-up gave me pretty much all I needed and apart from a few tutorials was very easy to learn.

Anyway, thanks for heads-up, I reckon I might try it out myself (if my very basic specced box can cope with it).