On 8 February 2016 we launched an ECO2 consultation on requirements for overwriting U-values for cavity wall insulation (CWI) measures. Our final policy includes the introduction of a cavity wall U-value checklist which is required for all CWI measures with overwritten U-values installed from 1 June 2016. For further details about how we came to our final policy please see our consultation response document.
The cavity wall U-value checklist is designed to:
This checklist also contains further information and guidance on our requirements for CWI measures with overwritten U-values.
Please note that on 6 May 2016 we published an updated version of our response document. This was to provide additional clarity around how a U-value should be overwritten where it exceeds the relevant threshold for CWI measures. We have reflected this amendment in the text accompanying the cavity wall U-value checklist. These amendments do not introduce any changes to our policy.
On 3 October 2016, we published an updated version of our cavity wall U-value checklist. This update reflects changes to RdSAP convention 3.08, as shown in RdSAP conventions v9.0. These changes came into effect from 1 October 2016.
The change has expanded those treated to have suitable expertise and experience to produce U-value calculations to include Level 4 Non-Domestic Energy Assessors (England & Wales) and/or New Build Scotland Non-Domestic Energy Assessors.
Operatives with these qualifications will now be able to complete the checklist where the U-value is below the threshold for the relevant age band. Where a U-value exceeds the relevant threshold, they can produce a calculation where the inputs are based on either construction details and specifications or a core sample tested in a laboratory. We have reflected this amendment in the cavity wall U-value checklist.