Laurane
Canadian Loonie
you can build, with this new system of Hook & Build.......just a 40 foot container and wood.......and the roof line (though a bit odd) would certainly help provide runoff for water storage. These were for tsunami relief, but could be used anywhere. My daughter is looking into building a Hook and Build Timber frame 2 storey house using this system (not the container type) - doing the Shell house and finishing it as they can afford it.
http://web.mac.com/wwilbert1/Hook&Build™Building_System/Container_Housing.html
http://web.mac.com/wwilbert1/Hook&Build™Building_System/Container_Housing.html