Adding Space to Your Home?

So lately, I've really been wanting to create some additional space at my own house. I've thought about adding on to the back of the garage, or maybe even creating a second story on said garage. Not anything that is going to cost an arm and a leg, but also something that can't be done in a couple days.

I may have found my solution. Abod was created by BSB Design to provide affordable housing for families in Africa. They are mass produced and deliverable by truck, ship, or plane, this "home in a box" includes the entire 120sf structure, unassembled, that fits into a box. It's apparently ridiculously lightweight, and can be put together in one day by four people, using only two hand tools - a screwdriver and awl which are included in the kit.

Now, I would be using the structure for something completely unrelated to its intended use, and I'm not sure if that's offensive or not, but I would think this would be an extremely cool space to add to a backyard, or in my case, maybe behind my garage and out of the way. I think it would make for a really cool office space or place to hang out...

Thoughts?