New construction settlement cracks in a masonry basement. What is still "normal"?

Hello dear forum, about half a year ago it was finally time and we fulfilled our lifelong dream by buying an almost new architect-designed house. (Built in 2019 using solid construction). Already during the viewing we noticed there were settlement cracks in the basement. According to the seller's statement at the time, he had this clarified with a structural engineer and it was considered harmless. Unfortunately, contact with the seller has since been lost and we can no longer communicate with him regarding this matter (according to him, divorce stress and he wants nothing more to do with the whole topic). We know very well that we should have been more critical back then, but unfortunately that doesn’t help us anymore. Now, after about half a year, we have the impression that some of the cracks are becoming wider and longer. The crack width currently ranges from approximately 0.1 to about 0.7 mm. The cracks are almost always vertical and reach about three-quarters of the wall height. Especially in the area of the window reveals (since the load distribution is already uneven here due to the geometry) and the partition walls to the other basement rooms. Now we are wondering if this is still within the normal range. The house is only four years old and the ground is clay soil. According to the building plan still available to us, a strip foundation with a somewhat thinner floor slab was constructed. Unfortunately it is not clear whether there was a gravel fill or something similar. According to the seller’s statement at the time, the walls themselves were built from concrete blocks filled with concrete and reinforced with steel. I have not yet been able to reach the architect. We still have time to formally complain and file a defect notice. We are still within the five-year period. The question is, who is ultimately responsible if this constitutes a defect. The architect? The basement or shell builder? Unfortunately, we don’t know. Perhaps someone in the forum has already had similar experiences or can provide valuable advice. Maybe the whole thing is harmless after all. Best regards, Claus

Looks okay at first glance, so rather a cosmetic defect. But since you are still within the warranty period, I would still have the contractor come around. Maybe he will offer something.

It was the same for us. After 3 years it was over. Then filled and painted. Tip top

Great what you recognize in these picture excerpts, without a floor plan, without knowledge of load-bearing walls, etc. At our place, the construction technician from the general contractor was already there because of a 0.3mm crack in a non-load-bearing wall on the upper floor, because he said he couldn't assess that from a distance with a few pictures. Get a professional to look at it on-site, everything else is crystal ball-gazing.

Why does one sell an architect's house after such a short time? There may be several reasons for this, but it is not the normal case.

I would immediately suspect that something is wrong here. Of course, there may be family reasons. Sure.

If I were in your position, I would first examine the cracks myself. Remove the wallpaper and apply gypsum markers. Then observe over a few weeks. Also apply the gypsum markers over the smallest cracks.

If in doubt, chip off the plaster and observe the masonry. Possibly also the floor or the connection of the wall. If the foundation settles, you have to observe that, but then I would also suspect cracks in the floor slab.

However, you don't need to worry. Cracks especially under the windows often occur. Structurally, however, they are mostly harmless.

So as I said, take down the wallpaper and first apply gypsum. If that also cracks, which it does with the smallest movements, then your house is still settling. I don't know the tolerances for such cracks either, but I believe there are concrete measurements.

Now, after about half a year, we have the impression that the cracks are partly becoming somewhat wider and longer. The crack width is currently approximately 0.1 to approximately 0.7 mm.

For documentation, a scale should be attached to the cracks. And it should be possible to identify in which areas they are located, in case you want to assert your rights later on. Documentation of whether or to what extent the cracks change should also be done.

Was there a soil report back then?