A chance to live in paradise ...
Housboats do come up for sale and rent and are often snapped up by someone already living on the island. Two of the last three renters on the island have moved - to a bigger boat!
Property prices and rents are not cheap. The island is finite, and there are no other island communities within the M25 that have security of tenure, road access, mains gas, proper sewerage, up to 15mbps broadband and 35 minutes by train into London - (Zone 6)
Nothing at present.