Insulation mare!

Just a quick update on the latest issue I have been having with the insulation that goes in between the outer and inner walls of the extension...

Decent insulation was a really important element of the design as we are having well over 25% of the floor area as glazing in the roof and walls. To do this and stay on the right side of building regs you need to show you are going to have zero carbon impact ( relative to having exactly 25% glazing) so you need to have an SAP report done to asses the CO2 impact from heating compliant and actual extensions. Initially the architect suggested we applied to build a conservatory (which are treated much less vigorously) and then nock through AFTER building control had signed off. I have no idea how common this practice is but I decided for the sake of a couple of hundred quid it was not for me. We got the report done and passed building control. Sorted!

Something had been bothering me for days then it struck me. My builder had attached the 5mm insulation boards to the outer leaf of the wall (within the cavity) my trusty Haynes extension manual which I fully recommend, http://www.amazon.co.uk/Home-Extension-Manual showed it attached to the inner block wall which made sense to me. I queried this with the builder who said it was fine then I queried it with the manufacturer who said it was definitely not fine!!! The walls had already been built up to ceiling level what a nightmare!!!

I decided to call building control and check what they thought. They agreed with me, but it turns put one of them had already been on site yesterday and had signed it all off. Unbelievable what I paying the (£450) for???

Building control turned up today said there had been a complaint (pissed my builder right off!!) and told them to sort it. Back tomorrow to check. Called my builder today to clear the air. Oh dear.......