Exterior plaster has strange stripes, looks like grooves.

It is not about any "technical" disadvantages..........if I pay for plaster facade XXX...amount, then I expect corresponding quality, right......??

Then just report it to customer service. We built with Bien-Zenker in 2017, and everything was always fixed to our satisfaction.

Could be due to the construction resulting from the wall structure of the prefab house. I have a prefab house from another provider next door, which has a "seam" horizontally between the ground floor and the upper floor in the plaster. It also looks awful but apparently that's how it is.

So I don't have something like that..

It could be due to the construction as a result of the wall structure of the prefabricated house. I have a prefabricated house from another provider next door, which has a "seam" horizontally between the ground floor and the upper floor in the plaster. It also looks awful but apparently that's how it is

Yes, I agree with one user that it probably has no impact on the proper function of the exterior plaster. But to now attribute it to the wall structure or the modular construction method and thereby legitimize it is completely wrong in terms of its effect. It simply wasn’t done properly. A base coat is, among other things, there to "even out" the irregularities of the wall structure regardless of which wall structure prevails. In this case, the original poster simply dropped the ball. Therefore, he now has to chase after the tradespeople, and since the trades of the larger general contractors often travel 300 km or more, it will take a while before anything happens, if anything happens at all.

There is also a guideline for the visual assessment of surfaces. This guideline clearly states that the surface should appear uniform and without traces of streaks. That did not quite work out in my case. I am reporting to Bien-Zenker and waiting for hopefully a positive response.