Is this cavity wall insulation?

[Mart]

Hi all,

I'm getting quotes on having a heat pump installed and the installers are asking whether I have CWI as it significantly affects the heat loss calcs.

EPC says I don't, however when I had a vent installed for wood burning stove the installer remarked that I did in fact have it. There are no tell-tale signs however the whole house appears to have been repointed at some point so this could predate that.

For "old house reasons" I'd rather not get CWI installers round to drill my wall to check so I found a small gap near the vent and had a look with a borescope - does this look like glass fibre insulation or just 100 years of detritus? This is only about 60cm above ground level.

Apologies for the terrible photo!

 

[a twig]

Personally I would completely ignore your EPC.

When I sold my last place I showed them photographic evidence of the extensive IWI I had installed, double glazing, LED lighting etc and none of it appeared in the EPC as it was “not visible”.

I’d go on what you can actually see - that looks like insulation to me

 

[a twig]

If you want to be safe, I’d suggest you get the installer to discount your CWI as worst case you end up with an oversized unit, which is better than being cold

I’m sure others will have opinions