At least Insulate Britain had the right basic idea but absolutely no clue about how to implement it for the UKs housing stock without creating much bigger problems due to lack of ventilation.

Hardly insurmountable problems - various 'robust detail' documents and compliance guides are full of proven solutions, Even if you get to completely air-tight, sticking  in a heat recovery ventilation system is hardly rocket science - both my previous and current houses have one.

   - Andy.

At least Insulate Britain had the right basic idea but absolutely no clue about how to implement it for the UKs housing stock without creating much bigger problems due to lack of ventilation.

Hardly insurmountable problems - various 'robust detail' documents and compliance guides are full of proven solutions, Even if you get to completely air-tight, sticking  in a heat recovery ventilation system is hardly rocket science - both my previous and current houses have one.

   - Andy.

As I sit with plenty of personal lagging on in my freezing (55 deg F) office at home, improving the insulation of the house makes a lot of sense, but there are limits. The walls cannot be clad externally 'cos the conservation people would have a hissy fit, and the interior decor (cornicing, picture rails, dado rails, and skirting boards) prevents internal insulation. Insulating the floor (suspended wooden joists) might have something to offer. Best option is likely to be secondary double glazing.

Up to this year, I could overcome cold spells by spending on gas, but not any more so the equation now looks very different.