My point is that not all houses can be insulated externally. In fact, many cannot even if it would be technically viable.

I thought it was pretty obvious but happy to clarify!

Are electrical combis actually better than gas though? Sure there will be fewer emissions on the edge (the end user house) but it’s not nearly as efficient as a heat pump, which would put pressure on the grid, increasing the need for gas and coal power plants.

I’m wildly speculating here though, I have 0 data to back up this hypothesis.

I live in a conservation area where external insulation will be a hard sell. There’s a lot of such areas around, some a lot more restrictive than where I am.