Can anybody recommend a useful house schematic programme?

Something not too involved, basically showing wall, roof, doorway and window dimensions. Also, can be printed off at a decent scale on A4.
This would be for a two story cement building outside Pattaya.

How much detail is required for actual "planning permision"?
Do I need a professional at this stage?
Are dimensions enough or do I have to include the drainage and circuits?

(Apologies to all the old hands if there is already a thread, but my search couldn't find one).

thanks.................