What ho one and all,

Just been watching an item on the BBC regarding below standard EWI (https://www.bbc.co.uk/news/articles/c203rnepzexo) I guess this is similar to the poor cavity insulation.

Is the failure of either type of insulation because it is a mistaken concept, or because of poor installation by snake oil installers?

As an aside, am not considering either, just interested.

In the article the surveyor says it is rain penetration due to poor workmanship and bad design.
Could it be rain getting in the top or edges?
As with many news articles, the lack of full details results in a misleading headline
“Solid wall insulation bad”
Rather than
“Shoddy workmanship bad”
Which would be an unsurprising and less attention grabbing headline

Here's the NAO report they're talking about
https://www.nao.org.uk/wp-content/uploads/2025/10/energy-efficiency-installations.pdf

Of the EWI installations:

6% of homes had
"Major safety issues EG
Boiler flues too close to windows, doors or other openings
Live electricity cabling is left exposed"

92% of homes had
"Major performance issues EG
Poorly installed external insulation that permits water
ingress, for example where roof eaves have not been
effectively extended to fully cover the insulation
Inadequate ventilation, leading to increased levels
of moisture and pollutants"

1% had Minor Issues
"Weak points in external wall insulation around existing
features of the home, such as gas supply pipes
Drainage and gutters have not been reinstated
Missing documentation
Installers leave waste behind"



The homes with IWI had similar issues, but less frequent


Sounds like the government had arranged for the energy companies to pay for EWI through ECO scheme levy on customers bills. Ofgem were to verify this, they had appointed Trust Mark (private verification company) who checked that the installers looked competent to self certify their own work. The households had little say how the work was done.

The installers then ran a bit wild and none of govt/ECO/OFGEM/Trustmark/households had much overview what was happening .


There's also a big section about financial fraud, but the details are redacted

Posted By: Peter_in_HungaryThe Builder who installed the windows and doors had no knowledge (or training) about ventilation requirements for gas appliances.

The boiler was not fitted correctly or vents were blocked up or removed. You cannot rely on windows to supply the combustion air an air brick or other permanent means of ventilation is required. I fitted an "atmospheric" gas boiler in my last house and fitted an air brick and replaced an opening sash with a fixed grill in a small window. When I had the manufactures engineer commission it he pulled me up on the grill saying it was inadequate, that was until I showed him it's specification which was better than the requirement of the regulations. (perhaps the regs different in Hungary)?

Posted By: WillInAberdeenThere's also a big section about financial fraud, but the details are redacted

Sorry, I don't understand this point. What has been redacted?

"We
do not comment on ongoing investigations on suspected fraud."

The fraud section of the report talks in high level terms about "inherent risks in the scheme design" and "did not carry out a fraud risk assessment". But doesn't give details of any specific frauds that were detected.

When we consider that the disasters of previous schemes (put the search term 'Disastrous Preston' into a search engine) gave rise to the Bonfield Review, PAS 2035 and the Retrofit Academy etc it is heart-breaking to see the same old things happening.

I visited a grant-funded IWI scheme recently. It did not make me deliriously happy.

As others have suggested, 'Badge' schemes are of little import if you sub out to people without the badge. And 'down to a price' is unlikely to equate to 'up to a standard'.

At least some IWI is being done as it was over 40 years ago when we didn't know how to do it right.

Didn't follow closely but a house in my road recently had EWI and I noticed they did not seem to be taking the air bricks into account. I mentioned to the householder and hoped that I was not being a busy-body, but he seemed totally unconcerned. Probably because he works as a financier in the city and knows nothing about building. Don't know how the EWI is holding up; guess only time will tell.

When I built, I decided too late in the day the EWI would be a useful option but the BCO told me that I would have to reapply to building control since that would be altering the agreed details. He also said, that since the external wall is ventilated, unless that cavity is filled, EWI just adds depth to the external wall and will not reduce the heat loss from inside.

Posted By: fostertomAin't the point of redaction that you can't see 'what'?

The point is that it's a document that has been produced and then had portions removed (usually blacked out) for one reason or another. I don't believe that's the case here. I don't think the document originally had any details of specific frauds; I think it would be very unusual for any such details to be released in advance of prosecutions being concluded, and I'm not surprised that in their list of things they don't do they included a statement about not commenting about ongoing fraud cases.

Posted By: stonecoldInterestingly, a Scottish study - the "pink house" case study - found that retrofit of MVHR was more cost-effective than EWI/IWI because of the heat recovery. You need a recirculating cooker hood and to remove and block the holes for any bathroom fans for this. It also means that you can get windows without air vents in future, and helps massively with damp especially from condensation in my experience.

MacLean Scottish EnerPHit "Pink House" Study:https://www.esru.strath.ac.uk//Documents/MSc_2015/MacLean.pdf" rel="nofollow" >https://www.esru.strath.ac.uk//Documents/MSc_2015/MacLean.pdf

When I was doing my build the BCO asked what it was that was mounted on the plant room wall I replied it was an MVHR unit something, he had not seen before but knew about them.

Whan he called a few weeks later he mentioned that after leaving me he went to see another build and spied a MVHR unit, but the builder had not understood what they did and had fitted windows with trickle vents!
In the building trade I believe there is a considerable lack of underpinning knowledge.