CONCRETE houseboats may be a rather odd sounding solution to building on flood-prone land but they could be an option as the population goes up.
Increasing pressure to develop new housing, especially in the south-east, might mean using flood plains - notable schemes include plans for the Thames Gateway.
Risks could be cut if houses rode out rising waters, f loating up and dropping back.
That is exactly the principle used on a dozen experimental houses built recently at Maas Denbursch in The Netherlands.
The concept, developed by Ger Kengen at Factor Architecteren uses riverside space that is regularly inundated in winter and otherwise useless.
Each house has a concrete basement with high walls, forming a kind of swimming pool shape. Over the top a more conventional but lightweight superstructure is built.
The watertight basement is kept in place by an outer concrete wall, explained Ronald Krommendijk, of contractor Dura Vermeer, which built the prototypes. He added: 'Flexible couplings beneath allow the gas, electricity and other services to ride with it.'
Side posts keep the units in posit ion as they rise up to 3 m.
The technique will add around £7,000 to the costs of a house, he said, but demand for the first dozen units was strong.
He wants to build more.