Just discovered that Google has a handy drawing tool available. It has engineering and architectural templates as well as a template that can overlay on Google Earth. Quite powerful for a simple tool to draw up your projects, and it is 3D as well. Check it out if you are tinkerer. There are free Google Sketch Up downloads for both Windows and Macs.

SketchUp is a powerful program. Now up to version seven. If you put your design in Google earth it will scale to the land you put it on. Great for sizing house to land although it will just be on your computer.

I used it a lot when I built my present house, used it for quick detail work to show the builder how I wanted a certain feature done. I also used it to redesign and re site the stairs to the mezzanine floor. Very powerful little program indeed.

Google Sketchup is also a very good tool for shading analysis - very useful for Thailand...

I prefer OpenOffice & Tiny Cad.