Question for the insulation/ heating experts.
I've got a detached house with a modern boiler, 8" of insulation in the roof and double glazing. It has cavity walls which, apparently, are too narrow for insulation. It seems to have loads of ventilation for the underfloor and the cavities, can this be blocked or restricted?
We are bl**dy freezing! Any ideas to help warm it up would be appreciated. Interior and exterior wall insulation has already been discussed and probably not feasible