Opinion on various prefabricated house providers desired

A company philosophy (from smaller enterprises) can also be no big marketing but rather communication and quality as a philosophy! Glossy brochures say nothing about that.

But you initially said

and deal with the company philosophy [...] !

That one should read it in the sense of

to be able to differentiate that, you simply have to be very reflective, realistic, and take your time!

as "prefer your favor to companies that have a philosophy instead of arrogantly letting their advertising agency write about it in an explicitly titled section on their website," oh, that takes quite a bit. After all, there are fifteen federal states without the Bavarian school-leaving exam ;-) and a Pisa society has fewer humanists than Zlatkos.

And wall constructions are not all the same. The quality differences are enormous! But that too requires the willingness to deal with it.

Here I want to disagree with you: within a wall philosophy category, the differences between wall constructions are not greater than between the recipes for Prinzenrolle vs. Doppelkeks or Nutella vs. Nutoka. Precisely every industrial baker knows that he has to have a spelt bun in the range for the “organic” customers (simply because “spelt” is a positively image-effective buzzword among the target group). In the same sense, mineral wool insulation is well received. A rogue who thinks of the psychological effect of the association and attributes its popularity to the raw sugar brown coloration, which of course per se is more trustworthy than the bright yellow of glass wool. Just yesterday I read here again about ground thinning waste recently being filled into hollow brick chambers. And as a fragrant crust then comes the clinker from the Rügenwalder Mühle, from the beautiful bakeress, or am I mixing several commercials now? – and like a CNC yeast dosing machine, the U-value calculator tells how many centimeters of material thickness of which building material you have to throw into the batter so that it is exactly done after the desired baking time.
Actual differences exist, too, but they then lie not within one category, but rather between e.g. wooden “stud” (actually “frame panel”) and solid wood.

And wall constructions are not all the same. The quality differences are enormous! But that also requires the will to deal with it.

Of course there are differences. I have dealt with it myself. But if you look at the wall early on (personal KO criteria like Styrofoam excluded), it distorts the view of the essentials. The differences within a price category are not that big, especially with prefabricated houses it almost always comes down to ~25cm mineral wool as the base.

But if you look at the wall early on (personal deal-breakers like Styrofoam excepted), it obscures the view of the essentials.

From my point of view, that distracts the focus too much to school physics. I consider the "chemistry" between the building client and the building contractor to be more important and know many happy people who have never looked under the skirt of their house's wall construction. My grandma lived happily in her last apartment for thirty-six years without ever asking whether the house was built from pumice or porous bricks. She could have distinguished Jacobs coffee from Darboven. But she never made a science out of stones.

What strikes me is that five-year-old ETICS houses in the north, where the sun rarely shines, are starting to develop algae.

I do notice that here five-year-old ETICS houses in the north, where the sun rarely reaches, are starting to get algae.

Yep! Our settlement is getting algae :oops: But what the heck, if everyone joins in :D

I can only partially understand the issue with the algae.

According to a painter, it also depends on the additives in the paint. Algicides and fungicides must be included.

There are 6 houses in the neighborhood
Only 1 house has problems

That is the Massa Haus, which has extreme streaks and spots on the west side. Whereas the one from Okal Haus has zero problems; they somehow belong to the same manufacturer.

After 10 years, however, even the massive ones have problems if there is a lot of brushwood and trees nearby.