Styrohomes

Houses of the future may be built out of polystyrene blocks and concrete if developments in the UK housing industry take off as hoped. Styrostone is a system of hollow polystyrene blocks
that interlock like Lego. Concrete is then poured to fill the hollow
chamber and a cladding of choice - from stucco to brick veneer - used
to cover the exterior.

The system allows fast
construction and exceeds all government requirements on thermal and
sound insulation. The Telegraph reports that it takes just 10
days to build the structure, excluding the roof, of a typical
two-bedroom house at a cost of roughly £10,000. About 50 houses have
been built in the UK using the method since Styrostone was introduced
eight years ago but demand is now "taking off". 

Telegraph Article
Styrostone