I've been a bit obsessed lately with homes built from shipping containers - another glance towards minimalism. For five childhood years I shared a 22ft x 7.5ft residential caravan with three other family members. In the 1970s, after 18 months in a London bedsit, my wife and I lived for three years in an identical van.
I admire the radical efficiency of small living spaces; especially when there's currently insufficient UK housing to go round. I know it's nicer not to have to practically rebuild the bed before you can climb into it every night, but what a waste it is to create separate rooms for living and sleeping. A traditional residential van is a third the size of a 'building regulation compliant' one-bedroom home for two (50 m2) - and yet, with a bed that folds down out of the wall and a composting loo in a shed, a caravan has all you really need for creature comfort. We even had an automatic washing machine, a coal fire and an old-fashioned valve TV taking up space (and how!).
The biggest problem, - even with temporary structures (the category most container homes would naturally occupy) - is finding suitable sites. You can buy a basic 30m2 container home for £25,000, delivered. It would be hard to get a conventional mortgage - but for that kind of money you can buy a mid-range car. So why would finance be a problem?