It amazes me how awful a lot of the UK housing stock is from an energy efficiency point of view. And in many cases it's next to impossible to improve it without either demolishing it, or essentially adding an extra house over the top of the existing one.
It's worth remembering that differing qualities in housing has always existed in the UK.
I live in a 1890's flat, that is part of a terraced house, originally designed for the workers of a mill opposite.
It's single brick and as regards building quality - utter shite.
Elsewhere in Chesham you can find beautifully built, thick walled houses of the same era that are worlds apart in terms of quality - and so much versatile to adapt and improve
in line with modern standards.
The council houses/ flats built after the war during the late 1950's were all internal solid wall construction and some of the best social housing we've ever built.
Then the 1960's arrived followed by the 1970's and a bit like the car industry [gotta love British Leyland, cracks me up] we managed to lower the standards alarmingly. Compared to what went before, some of the garbage that was built is shameful.
And onto today.
As regards insulation though, it's a slippery character, you have to be careful what you're doing with it. People wonder why that stuff the loft full on insulation, block up the air vents of suspended floors and then wonder the roof is dripping with condensation and the floor joists are starting to rot. If you've got a lot of timber in a house....it HAS to breathe. You can still insulate but it's important to respect how the building works. In an odd way a house is a living breathing thing!!
Anecdotally, my flat is flying freehold, suspended over an alleyway. I replaced all the old lathe and plaster ceilings with 100ml celotex and plasterboard some years ago.
In the winter, I can return home and it feels like the central heating has been on low all day [even though I have no central heating] but in the summer, when it's hot [sometimes] it's created a whole loads of other issues - once the heat gets in it's a bloody nightmare trying to cool the thing down again!! I don't want a heat box in the summer! [closes all windows and doors] .
Double-edged sword. Insulation can make a house much colder too. But that's what insulation is supposed to do, right? It works both ways. So now, with the celotex reflecting heat away, on those sunny spring and autumn days, I'm not getting the sun radiating through a poorly insulated ceiling, and I've made the place cooler than it was before.
It's a slippery beast.