im pretty sure solidworks has a free 2d CAD thats almost the same as autoCAD but legally free.

autoCAD isn't exactly user friendly lol.

Like FMX said I don't see any reason why you couldn't do this on paper. That would be by far the easiest.

autocad = drawing with llines and shapes. pretty simple

Have you ever used autocad? lol. Its all command based. You need to learn the proper commands to use it properly. For what he needs drafting by hand would be easiest.

Anything fancy is a waste of time. A licensed architect will have to redo it anyway. You cannot pull a building permit for a dwelling without an architect or structural engineer's certification. You won't find one that will stamp a plan you drew yourself either. His ass is on the line for it.