Derwent London takes sustainability very seriously. As the largest real estate investment trust focused on central London commercial property, sustainability is built into all aspects of our business. We seek continual progress against a range of targets because we believe this will strengthen the viability of the company and underpin our principal objective of delivering above-average, long-term returns to shareholders. By improving the environmental and social impact of our properties we reduce construction and operating costs and make our portfolio more attractive to both tenants and investors.
A key method of reducing our carbon footprint is to minimise the number of new developments, preferring to refurbish our properties instead. This conserves embedded carbon and significantly reduces the transportation of demolition and construction waste, cutting both emissions and costs. We also maximise the use of sustainably sourced timber and install a wide range of environmental and energy-saving features.
The strength of our sustainability policies was recognised last year when we received an 'Excellent' BREEAM rating for the Angel Building, a redevelopment in St John Street, EC1. The Building Research Establishment Environmental Assessment Method assesses the operational and embodied environmental impacts of individual buildings and 'Excellent' is a major achievement for a refurbishment. The original frame of the building was retained and new features were included, such as high-performance glazing, low-energy lifts, intelligent lighting, biomass boilers and the use of harvested rainwater in the WC cisterns. A displacement air-conditioning system using heat recovery was installed, which gives a 44% reduction in CO2 emissions compared with a fan coil system. The Angel Building received a 'B' Energy Performance Certificate (EPC) which is only awarded to exceptional air-conditioned offices, whereas central London new buildings typically receive a 'C' rating.
We continually push the boundaries, working to anticipate future legislative requirements and the needs of our tenants. Recent planning applications include our 'White Collar Factory' concept which relies on the generous floor to ceiling heights of many older buildings. Features include natural ventilation with opening windows and thermal mass cooling, which uses exposed concrete walls and floor slabs to absorb heat during the day and release it at night. Additional cooling is provided by retrofitting capillary tubes in the ceilings to carry chilled water.
Derwent London's commitment does not stop when construction is finished. We work with our consultants Arup and in partnership with tenants, suppliers and staff to reduce resource use and improve waste recycling. Derwent London also helps tenants to measure and reduce their exposure to the Carbon Reduction Commitment Energy Efficiency Scheme (CRCEES). In 2010 we implemented tailor-made programmes which reduced carbon emissions by 19% at one building and by 7% at two others. We also installed water sub-meters and new waste measurement systems across our portfolio to measure consumption and recycling more accurately and are working with suppliers to include formal sustainability requirements in their contracts.
Last, but by no means least, creating a positive impact in the local communities where we operate is very important to us. Our projects are registered with the Considerate Constructors Scheme and the Angel Building recently came in the top 7.5% of sites, earning a bronze award. We also participate in a number of local partnerships focused on regeneration and enhancement of their respective areas of central London.
Sustainability is an increasingly important issue for everyone. At Derwent London we have made good progress but are very conscious there is always more to do. By working with our tenants, suppliers, staff and local communities we believe we will continue to improve, making our portfolio more attractive and delivering better long-term returns to shareholders.