Here’s my largely inaccurate history of house building.
After all that wattle and daub stuff, someone invented the brick wall. In the 1930s someone else invented the cavity wall, which trapped an insulating layer of air, but was still cold in winter. More recently someone realised injecting the air cavity with an insulating foam was even better.
In the last few years, about 30 year after the rest of Europe, the UK Government finally adopted building regulations to require proper home insulation in the first place!
But that means 80% of the homes with us by 2050 have already been built, are poorly insulated and expensive to heat. And a good proportion of them have ‘solid walls’ which can’t easily be insulated by filling the cavity.
The answer for these solid wall homes is to stick the insulation either on the inside of the wall (which makes the room a bit smaller and you need to redecorate) or on the outside of the wall (in which case you need to re-render). It’s like wrapping your home in a warm duvet. But either way it’s quite disruptive, so is best done before you move into your new home.
As you know we are quite keen on insulation at The Secret Acre, being fully paid up members of The League Against the Payment of Large Heating Bills.
So when our last lorry load of insulation arrive recently, it was for our external wall insulation, the foam boards being screwed to the outside walls temporarily turning the house a stealth plane black before the render returned it to normal.