Milton Keynes Council has established policies and a carbon offset fund to work towards making all new development in the city carbon neutral. The local plan policy D4 requires new buildings to meet standards for energy efficiency, renewables, water conservation, and materials use. Developers can automatically comply by achieving BREEAM Excellent or Code Level 4 certification. Compliance comes at an estimated 5% additional cost. The carbon offset fund uses payments of £200 per ton of unmitigated CO2 to finance insulation and efficiency projects for existing homes, lowering emissions and saving households money. So far over £1.2 million has been collected and invested in insulating over 5,000 homes, saving 3,800 tons of emissions annually.