Not all residential properties are houses or flats. More than 150,000 people in Canada live in a mobile home or static caravan on a permanent basis, and another 15,000 people live on houseboats. Almost any type of real estatecan be converted to residential use, some with extensive modification, some with very little. Farmhouses, and other farm buildings such as barns and stables, are popular conversions. More unusual residences to hit the market include Martello towers, nuclear bunkers and oast houses. Once a year or so, it seems, British newspapers will run a story about a former public lavatory selling for conversion to a home.