In sustainable construction, it is easy to become interested in all the exciting new build schemes. They look good, they test innovation and they are good publicity. But the biggest environmental, social and economic impacts of the built environment act through the existing stock.
The paragraphs below give a United Kingdom perspective on sustainable refurbishment.
Of the stock that will exist in 2030, 2/3 is already in existence: new build only adds 1-2% to the built stock each year. The rest is likely to have been refurbished - possibly several times - and the nature of these refurbishments is vital for the health and productivity of people who live and work in these buildings, as well as for reducing our environmental impacts.
The challenge for refurbishing and upgrading existing stock is immense - refurbishment projects obviously need to upgrade the structure, the fabric and the buildings services whilst complying with new standards and legislation, but they should also:
Some buildings are cherished, while others are seen as liabilities that are poorly managed until demolition is the only option. This is partly a social and cultural construct. However, in environmental terms, many older buildings (particularly 18th and 19th century buildings) have key characteristics which make them more adaptive and resilient: modest plan depths, high thermal mass, high ceilings and narrow windows. There are lessons to be learnt from the built heritage that has survived thus far. Heritage features are valued by occupiers, but have to be part of a functional whole.
'The dilemma of whether to refurbish or rebuild new is never an easy one, from a sustainability view-point. But generally speaking there will only be a case for partial or complete deconstruction and rebuilding, if the new facility will achieve truly leading-edge performance (i.e. zero carbon like BedZed). Otherwise, and this is currently the more likely scenario, retaining and enhancing existing structures is likely to be preferable, especially when they have innate quality of design or construction. (This is of course a bold oversimplification!)' Dave Hampton, Chairman, CIC Sustainable Development Committee.
The National Trust
The National Trust - a UK charity that protects historic buildings - is a well-known example of a property owner that has sought to reduce the environmental impact of its buildings:
Sainsbury's, a UK supermarket chain, annual energy costs are £50M per year. They aim to reduce carbon dioxide emissions by 10% from 97-98 baseline by 2005. Reducing costs is a driver, as well as anticipating legislation, improving corporate responsibility, and improving comfort. A wide-ranging refit programme involves stepping down voltage supply (reducing energy use by 3%), modifying lighting and control (a reduction of 5%), and recommissioning, optimising and monitoring refrigeration units (a reduction of 10%).
In the housing area of Gårdsten, the public housing company Gårdstensbostäder has renovated four residential buildings with a focus on energy efficiency, the integration of renewable energy, sustainable design and improved quality of life. The renovation was planned and performed in close co-operation with the tenants.