Believe it or not, while watching The Weather Channel tonight, they had a feature up about a small, semi-portable structure that is an alternative to a nursing home for an elderly parent. They are one bedroom, one bath cottages with a small kitchen and sitting area. The approximate dimensions are 12 by 24. They come with medical monitoring equipment and video cameras. They are delivered on trailers or are trailers, I'm not sure which.
Definately an interesting concept. But $70,000?????? Wowza!
I would include the link to the manufacturer's site but that might not sit well with the GW hall monitors. Search "Granny Pods" and you should get multiple hits that all seem to link back to the main site.
By coincidence the dimensions are almost exactly the same as Jeff's Basic Person Structure www.verysmallhouse.com. Jeff's structure just might be adaptable to a similar use.