Flood-proof housing
As the floods of the past few weeks show, the UK is not particularly well-prepared for inundations and has to build more homes on flood plains. While a lot of the houses to be built to the east of London are (I think) protected by the Thames Barrier, a lot aren't. Here is my brilliant solution (with thanks to Trevor Baylis).
Build the houses with a half-sunken basement. Have steps and a ramp to access the ground floor (which would be a few feet up from the ground). Put tiles on the first floor instead of carpets (less flood damage). Put electric sockets half way up the wall (you won't have to bend down and the water has a lot further to rise before it damages the electrics).
xD.