Is there such a thing as an architects drawing app for free?

[kickassangel]

This sounds really vague and it is!

I'm doing a course about creative writing with new media, and I want to do a piece about how technological progress has changed our houses and space. I'm thinking about doing a building plan/architects drawing and instead of having numbers for measurements, writing in words/phrases which make up a 'story'.

So - is there anything I can get for free which would enable me to do this?

bumping now that it's UK day time

DH is using something called 'Sketch up' - is this any good?

I'll look into it, thanks