Evaluation of offer (5 windows and a balcony door including removal and installation)

I really don't know much about it. I have seen the MD in online configurations. There, the windows are overall much cheaper. [...] The installation costs seem extremely expensive to me.

There may be individual profiles that are so cleverly designed that they work well with the sealing strips. However, as a rule, in my opinion, it is always recommended to use the middle seal ("AD" practically means "without MD"). Buying with installation is certainly wise - but unfortunately, good installation requires professionals and therefore comes at a corresponding cost. Window installation is unfortunately an industry without a certificate of competence, i.e., with a permission that formally does not require skills. Accordingly, more fearless opportunists operate in this field than our academic wisdom would suggest. My main reason for withdrawing from the window industry was the shortage of skilled installers on the market.

I just wonder why only double glazing is installed? That is as of 1995

You can also calculate the windows on the online page Fensterversand to see if the price is correct.

I just wonder why only double glazing is installed? That is standard from 1995

When renovating, triple glazing is not necessarily better. In general, that is once again a pub cliché without real substance.

Well, a U-value of 1.1 is not a pub talk catchphrase.

Well, a U-value of 1.1 is not just some barroom slogan.

But you don't know anything about the U-value of the exterior walls. In that respect, it's simply to be regarded as a saying... everything has to fit together in a house! And if Joe had built in 1995, he certainly wouldn't have had triple glazing as a standard in his new building.