10% of all energy on new developments to be produced on site from renewable sources. First implemented by The London Borough of...wait for it...Merton. Not everyone likes it, the British Property Federation for one. This is what they say:
If the only method we use to measure green credentials is how much renewable energy we use, then it means we could leave the heating on full with windows wide open, keep computers on all night and lights on at weekends, but power it with 10 per cent renewables and still call ourselves green.