Hello,
We live in a midterrace house with the half-width extension consisting of kitchen and bathroom at the rear. We are looking to extend and make extensions full width, which means it will be between rear extensions of two neighbours. As initial extension was built in 60s or 50s wall when the requirement was 250mm wall cavity, whilst it is now 300mm due to higher insulation requirements. Whilst we are happy to have 300mm cavity on a new wall, we are a bit confused with existing wall. As our architect advised it is easier and cheaper to demolish whole extension and build it from scratch because "Builders can charge more for fiddling around (because it is labour intensive) than for starting again. Concrete blocks are only 50p each and it wouldn't take them a day to replace the wall.", which we also understand but behind our existing wall is the neighbours wall. It seems such unsustainable move to remove existing wall to comply with current regulations whilst there is neighbours wall right behind. Is there a regulation for cases like ours? We were also thinking to leave existing wall as it is by having full width extension for half length only? Please advise. Thank you.
