I raised this under 'Timber Frame' but there was no response so apologies for raising it again as this may be the more appropriate topic:-
Or is this too big a subject?
We built a timber framed extension some years ago without problems but we simply cannot wrap our heads around the new insulation requirements for another single storey extension we need.
Is there a layman's guide to the actual requirements which explains from start to finish how to calculate, from scratch, what is needed?
We don't need planning permission but we do have to meet building regs - but how?