On 10/03/2020 16:01, Harry Bloomfield wrote:
Brian Reay wrote on 10/03/2020 :
One of our previous houses had been extended like that. Fortunately,
there was a crawl space, accessible via a hatch in the garage, and I
was able to gain access. I lined it with foil and insulation. It made
quite a difference.

If there is a similar space, it may be worth making an access
somewhere is can't be seen.

He says not, but it might be worth his making some access to add
insulation.

It's not an extension, it is the originally built. I'm surprised that in
the 1960's this was an acceptable way to build homes. He says his was
one of the first, later ones of the same design had to have insulation
added.

'New' houses built near me in 2010 just had inch thick batts of
expanded polystyrene (the white stuff) just chicked inside the
cavity. No attempt to clamp it firmly to the inner leaf, so air
movement each side of the 'insulation' would have rendered it
ineffective.

1960's buildings need to be bought cheap (in poor condition)
so that remedial work (like pulling down upstairs celings of
chalet houses and fitting tightly fitting celotex with gaps
sealed with foaming adhesive between rafters) can be done
as part of the renovation.`