The district heating system at Roupell Park Estate in Brixton is being upgraded to a Combined Heat and Power (CHP) system to provide the residents with a reliable modern heating and hot water with low bills. The CLEAN ENERGY building will demonstrate green concepts by its functions and by its fabric. Its starting point will be the National Green Specification, and it will address strategic issues and show practical examples of energy and environmental conservation such as zero or minimal carbon, low embodied energy in materials, low energy in use, low waste generation, long durability, recycleability.