alt Hacker NewsElectricity prices are certainly a factor, and retro-fitting can be very expensive to nigh on impossible.
The real scandal in the UK is how the updates to building regulations to bring in higher energy efficiency have been delayed and delayed - presumably due to lobbying by UK house-builders.
Given the big push to build large numbers of new houses it seems madness not to have the higher standards in place.
Planning rules conflict with building regs in the UK. Planning means that most new houses are little boxes made of little more than ticky-tacky. So adding insulation to the walls makes them even smaller inside.