To calculate the U value, the construction of the wall is required and the type of material. Once U is known, then we can calculate how much additional insulation is required to get the U value down further and then calculate the cost benefit.

Ok, so clearly there will be more stringent building regulations for new homes ultimately resulting in a zero carbon home, but what about the millions of existing homes ? Here is the link to the Goverment’s Consulation documents. What this ultimately boils down to is - how are home owners going to spend out £1000’s [...]