Cavity wall insulation in the consumer unit. Electrics running in the cavity has always been seen as dubious and not part of best practice but the fact is older houses can have large amounts of wires within the cavity which needs to be considered during retrofit cavity wall insulation. Building regulations are clear that before installing cavity wall insulation any wires in the cavity should be identified and dealt with, preferably re-routing them.   Although BS8208 has been withdrawn. Thee majority of historical CWI installs were done with Agremént certificates which conform to this standard:  BS 8208 Part 1, 1985: Assessment of suitability of external cavity walls for filling with thermal insulants. "Where they cross the cavity. Cables may need moving or uprating before a cavity is filled (they can overheat if surrounded by insulation)." There is a significant expense in  recruiting the services of an electrician while doing a CWI install and it may cause significant delay

The IAA are a rebrand of CIGA. It's the same staff and HQ. So it didn't surprise me one bit to see misleading and or sloppy figures on their website. As we know they have 25 years pedigree of this. For CWI, IAA are claiming a purported annual savings of up to £610 A YEAR on their web site. Anyone involved in energy would realise this stands out as either a monumental breakthrough in energy efficiency or more likely just more quality control issues at CIGA. https://www.theiaa.co.uk/cavity-wall-insulation/ There is no reference to any sources which is poor practice in itself. But, I checked the Energy Saving Trust's figures and this shows where they got the  £610 figure from : it's the typical insulation cost for a detached home. The important step of selecting 'Energy bill saving' from the drop down menu reveals the more modest figures. The IAA state that Cavity wall insulation 'Lasts the lifetime of the property (if the property is maintained) ' where

Trustmark without ceremony have now put up CIGA2 The IAA (insulation assurance authority) as a Trustmark scheme provider as a retrofit co-ordinator scheme operator. The IAA  rebrand can use all their 'experience' and an appalling and amoral redress system which has been dragged in front of  parliament several times to mess with far more aspects of your house than ever before thanks to Trustmark. One of the big criticisms of the cavity insulation industry was that installers could grab the money from an ECO scheme,  fold their business and then spring up as another company and get re-certified within weeks without the hassle of complaints with CIGA doing a good job of batting off valid claims. With the help of BEIS and Trustmark, CIGA have done a macro version of this trick and managed to phoenix a scheme provider while keeping all the technical oversight 'in house'. Trustmark have essentially enabled the biggest Phoenix of all. Remember that without any precedence or a