ᐅ Is the installation of the insulation satisfactory?

Admittedly, he has only identified the obvious flaws. Whether the rest of the work—especially filling the gaps with expanding foam—is done correctly, I would at least dare to doubt here. He is responsible for supervising the construction process on behalf of his employer and will likely try to minimize any additional repair costs.

I would now involve an expert!

EveundGerd schrieb:
I would now involve an expert surveyor!

Overdue 😉

Regards, Bauexperte

HardyHard schrieb:
Gaps of 1 to 2 cm (0.4 to 0.8 inches) are within tolerance and do not require correction.

He should provide this to you in writing or show the relevant section in the insulation material’s installation guidelines... you will find that he cannot substantiate his statement...

Good morning everyone,
Yesterday, there was a site inspection by an independent building expert. The result was that the workmanship and materials (expanding foam) do not meet the standards.
A few other minor issues were also added to the list.
Thanks for the responses and have a great weekend.
Regards

Thanks for the update. The money spent on the expert already proved worthwhile. ;-) While it was obviously not acceptable in this case, he will surely find many other issues that are invisible to us laypeople. Well done. :-)