DIY project software

I've used EasyCad (available from FastCad for about £300, or trial download) for a few things. It's a 2-dimensional drawing package, like a baby-brother of AutoCad which costs several £000). Not 3D, but fantastic for scale drawings, layers, colours, tiled-over-many-page print, work in cm/inch on same drawing. I did think it could be used for a house extension - layers for ground, foundations, electric, walls, etc. (main reason was we have it at work, so it's free for me) just a thought. Neil