Please don't forget that my claim is in the context of somebody else claiming that insulating all housing in Europe would at least take 100 years.

Now you are literally redefining the terms I use and then quoting them back to me to argue your new semantics, are you serious?

On average, a house is considered to last 100 years in Germany. Call it economic lifetime or whatever else you want. I still stand by that claim, as it is common knowledge. I quoted specific numbers on the housing stock which are consistent with that claim (though no proof of causation, as there are plenty of reasons why we have a lot of new stock, for example in general rising number of buildings.)

And of course the insulation is not "for free", but the additional costs are usually worth it. I also mentioned that many people decide irrationally because they do not want the work associated with planning and ordering the maintenance to be performed.

None of this matters to show that the above mentioned claim how long renovation of the current housing stock will take is completely out of the world.

Note that I am by no means a civil engineer or architect, but following the discussion and researching the topics associated with the Energiewende in the different sectors for over a decade now. I may still well be wrong in this instance. But you won't convince me of that if you try to prove me wrong on semantics and just asserting that I were intellectually unable to understand your arguments. So please also state some relevant facts and sources to support your claims if you want to try further to convince me, otherwise continuing this discussion is probably a waste of time for me as we both will probably not learn anything new. Thanks.