This report is an update on an earlier report by Inbuilt and Davis Langdon published on our web site at the end of 2010 which gave an estimate for the first time of the number of hard to fill cavity walls in Great Britain.
The updated report has revised the original estimated range of hard to fill cavity walls in the 2010 report (3.9 to 5.8 million) to a range of 2.5 to 3.6 million. The update is based on an improved methodology, including using the 2008 English Housing Survey instead of 2007. The estimate has come down in part due to dialogue with industry stakeholders concerning the number of narrow cavity walls.
The update also breaks down the hard to fill group into several smaller categories with an estimated range given for each. These changes have been reflected in the Green Deal and Energy Company Obligation impact assessments and should be useful in continuing to design effective policies to improve insulation in the housing stock of Great Britain.
Green Deal impact assessment