These set the temperature profile and the surface check. They do not change the U-value, which is a property of the build-up.
A calculation to check, not a certificate. The conductivities listed are the range the published tables give and are a starting point only — a submission is built on the certificate for the actual product. Repeating thermal bridges at junctions, fixings and reveals are not included, and neither is a full interstitial condensation assessment. Nothing typed here leaves the page.