Britain’s oldest heritage body, the Society for the Protection of Ancient Buildings, and leading names in the property industry including Grand Design’s Kevin McCloud, are warning that older properties need special consideration when it comes to making them more eco friendly.
They are calling on the UK Government to consider the needs of older buildings as part of The Green Deal, a revolutionary programme to improve the energy efficiency of homes.
They have sent letters to Chris Huhne, Secretary of State for Energy and Climate Change saying that they are seriously concerned that the drive to promote the complete thermal upgrading of pre 1919 buildings could be storing up expensive future problems for both building fabric and human health.
Inappropriate forms of insulation and the sealing up of interiors take little account of the fact that these buildings, which number millions, perform differently from modern ones and need to breathe. They point out that they are likely to require a different approach, in particular with regard to the movement of moisture within them.
‘While we strongly support the aim of reducing carbon emissions from the nation’s building stock, we call on the Government to involve bodies knowledgeable about old buildings in research and planning for The Green Deal. Many of these bodies already have helpful research to contribute but to date have not been called on to do so,’ the letter says.
SPAB is currently conducting and collating research into the energy efficiency performance of a range of older properties built using traditional materials. Results to date suggest that these buildings actually perform better than expected.
The study suggests that conventional industry practices are struggling to accurately represent the thermal performance of traditionally built walls. Ultimately, this could have negative consequences for historic buildings as calculated theoretical U-values (suggesting a poorer performance) may lead owners and professionals to adopt disproportionate energy saving interventions that may not only be unnecessary, but also invasive and potentially harmful to the fabric of a building.
SPAB’s research suggests that 79% of the traditionally built walls sampled, including walls of timber, cob, limestone, slate, and granite, actually perform better than expected. Even taking into account a possible error margin of up to 10%, SPAB’s findings show that old buildings may not be as energy inefficient as the building industry has generally understood them to be.
The Society believes it is only by understanding old buildings fully that we can decide whether the insulation upgrades we are making are of any energy efficient or sustainable benefit.