KODA is a tiny solar-powered house that can move with its owners KODA by Kodasema – Inhabitat - Green Design, Innovation, Architecture, Green Building - created via https://pinthemall.net
Now here is a really cool and cheap Pre-fab homes for modern home enthusiasts.
little blue house ~ rusafova-markulis architects
The Backyard House: Built From Recycled Barnboards : TreeHugger
Cabin built for $500 with re-purposed windows in the mountains of West Virginia (with probably very little energy efficiency, but hey, it's pretty).
What happens when the guest house becomes home? Retired couple Suzanne and Brooks Kelley found out when a pair of brainy New Haven architects breathed new architectural life into the property they’ve inhabited for over thirty years.