The UK’s first “net zero carbon” house has been built at the Building Research Establishment’s premises in Watford for the OFFSITE2007 exhibition. The A-frame Lighthouse achieves level six of the code for sustainable homes, through features such as a PV-covered 40deg south-facing pitched roof along with a roof-mounted “wind catcher,”which provides passive cooling and ventilation. Designed by Sheppard Robson and …