The window company is not delivering the agreed roller shutter boxes

With silicon and foam, you can build entire houses *flööööt*

Sausage rolls & co. were also gladly taken by window sealers 1-3. So it doesn’t necessarily have a positive effect on the work result. But it is really the case that many don’t know any better. “We have been doing it like this for 30 years.” A window installer told me, whom I also contacted several times to see if he could fix it, that I can always call him and ask for advice, but only as long as he is not making my windows. Because according to German law, he takes over the warranty for windows and roller shutters he did not supply (upstream trade) and thus trouble is guaranteed. And even if the builder certifies in writing that he does not enforce these claims, this does not count in court and the well-meaning window installer gets the short end of the stick and has to vouch for it. I can of course fully understand that he then keeps his hands off it.

Exactly not finding a convincing satisfying answer to this was a very significant reason for me to temporarily disengage from the window industry again. Basically, as a builder, you have to reverse the whole thing, i.e. first look for a good installer and have them also supply the windows. But customers also have to contribute to getting this sick market back on track - because customers let their price expectations be spoiled too much by the included botched cheap installations. Therefore every good installer knows horror stories, but understandably does not want to experience the "the savior gets bitten by the dogs" situation for warranty reasons. In summary, what a customer can do: 1. be (also price-wise) aware that installation is an essential part of the "overall product quality"; 2. understand that the installer does not want to work for people who begrudge him the trade margin; 3. for safety, read up a bit about what should be considered during installation (as with ETICS, there are various expert videos about examples of horror); 4. (also in other areas, e.g. kitchen installation no less) avoid the craftsman type who comes like an action hero with a whole belt full of silicone and foam gun cartridges - because he usually applies them "one gun fits all" for everything that isn’t “three up the tree”; 5. plan vacation days to show presence on the construction site - see point 3, because playing the nitpicking controller who then embarrassingly cites the wrong standard naturally achieves nothing except undermining one’s authority. 6. Only when points 1 to 5 can be checked off positively (because otherwise it’s of little use) ! also contribute a little to the working atmosphere on the construction site with sausage roll catering & co.

Super, thank you very much for your efforts. Do you perhaps have a tip on how I can get craftsmen to accept any advice from me as politely or friendly as possible? I imagine that is not quite easy. More like asking questions whether this or that shouldn’t be better done this or that way? Or making clear demands? It has to be like this or that? Thanks!

Summarized, what a customer can do:
1. Be aware (also price-wise) that installation is an essential part of the "overall product quality";
2. Understand that the installer may not want to work for people who do not grant him the trade margin;
3. For safety, do a little reading yourself about what should be considered during installation (as with WDVS, there are plenty of expert videos about horror examples);
4. (also in other areas, e.g. kitchen installation no less) avoid the type of craftsman who comes along like an action hero with a whole bandolier full of silicone and foam guns – because they usually use them "one gun fits all" for everything that’s not "three on a tree";
5. Plan vacation days to be present on the construction site – see point 3, because playing the nitpicking controller who then embarrassingly quotes the wrong standard naturally achieves nothing but undermines his own authority.
6. Only when you can positively check off points 1 to 5 (because otherwise it’s of little use) ! also contribute a little to the working atmosphere on site with sausage roll catering & co.

Believe me , we did all that (at least we think so), yet the result is suboptimal.
Internorm windows were purchased from the certified (Internorm) specialist dealer with showroom and on the recommendation of our architect at (we still think) a fair package price. Had he said: I would like to install frame width compression tapes (extra cost €600) and clean masking requires 8 extra hours (~€65 each), for that you get (what you expect anyway, namely a cleanly installed window according to "DIN") then we would have been the last to say no. We definitely did not convey that impression solely based on the choice of our general contractor.
My sister-in-law was always on site bringing hot coffee (it was freezing) and cake. Our contractor kindly moved the window units (despite a different agreement) to the upper floor (½ day at our expense).

I came, there was talk about the foam (installers all more or less German-speaking but not German native speakers contrary to the impression given in the sales talk!). Sister-in-law insisted on installing compression tape, then a 2 cm narrow one was conjured up. Unfortunately, the window fitter came one day later than announced, I had non-movable appointments that day, so it was already done. Whether I could have prevented it/improved installation is questionable.
The boss was there himself!

In retrospect, we probably should have ordered the windows together with the doors. He did his work extremely precisely. So it can also be done differently.

Estimated additional effort for installation that I would have been satisfied with: a few hundred euros for the frame width compression tapes (as with the doors), clean masking also or especially in the corners, possibly 4 hours. So about €1,000 per semi-detached house. I would have willingly paid that! Yes, certainly. I just had no choice. :mad:

If he had said: I would like to install frame width compressible tapes (additional cost €600) and clean masking requires 8 extra hours (approx. €65 each), in return you get this (what you expect anyway, namely a window installed cleanly according to "DIN"), then we would have been the last ones to say no to that.

Do you know of a DIN standard for the sealing of windows?

The improper sealing is the least of the defects, the too small roller shutter box and the missing load support on the masonry are much worse. There is no double-leaf window fixed to the lintel and the windows are already sagging.