Impact joints between bricks - gaps present, defect?

Dear forum community,

In December we bought an apartment in a 4-family house, which is currently being built. We regularly visit the construction site; by now the shell is up and the roof is on.

Since my father-in-law completed a masonry apprenticeship 40 years ago, he pointed out gaps between some bricks. He thinks these need to be drilled out and filled.

I wouldn’t have noticed these narrow gaps at the joints myself, but I have now taken a closer look: There are about 20 gaps, 15 of them about 1 to max. 2 mm wide and about 1-3 cm high, 3-4 about 4 mm wide and also 1-3 cm high.

I noticed that almost all the gaps are in a row of bricks that looks “different” (darker stones, it looks as if there is no groove there, but they were laid flat against the next one; could this be a kind of barrier layer?)

I read that according to DIN, joint gaps up to 5 mm do not have to be filled. Now the questions:
- Is this a defect at all? (probably not, according to DIN, if that is what it means?)
- Should it be fixed? (thermal bridge, wind… after all, it is a KFW55 house)
- Should it be fixed free of charge?
- Although this is not my goal, should an expert be called in and he determines it must be fixed by the builder – do I still have to pay for the expert?

We have not yet spoken to the builder – I wanted to inform myself beforehand to be able to act confidently.

Here are four photos as examples, three of the “wider” spots and one narrow one. Unfortunately, I only noticed afterwards that some of the photos are blurry, sorry for that.

Many thanks for your opinions!

Narrow gap:


The “wider” ones:




unfortunately very blurry and therefore appears even wider:

Since the father-in-law completed a bricklayer apprenticeship 40 years ago, he pointed out gaps between some of the bricks.

Well, he should also have noticed that the bricks in the top row in pictures 1 and 4 are laid crosswise. With them rotated in this way, there are vertical joints where a horizontal joint is "expected" and completely unused. This is quite a rough apprentice joke. It is absolutely not professional. I even doubt that the construction approval for the bricks remains "valid" with this method of installation. I cannot assess the legal consequences. However, I urgently recommend documentation clearly showing the defects. And a verifiable notification to the responsible party (or better to all involved: seller, construction contractor, and building authority).

No, those are terminal blocks, aren't they?

No, those are formwork blocks, aren't they?

For a ring beam, you mean? - that's why I say the pictures should clearly show what they actually depict. If that is indeed the top row in picture 1 (and not just below the edge of the picture), or even if all the pictures are supposed to show the same situation, "I take it all back and claim the opposite." Under the ceiling or under the foot purlins, that of course makes sense that way (if they are formwork blocks). The concrete would of course only run up to the bottom edge of the "gutter," and at the height of the lower "covering" of the concrete, there would be these cracks. A bricklayer on site should be able to recognize that, as opposed to a business consultant looking at poorly "exposed" photos.

For a ring beam, you mean?

Yes. Under the "U-shaped blocks" there is also cardboard or something similar as a sliding layer, although I do not see the purpose of it. True - a mason should recognize that.

However, the Poroton masonry to the right of the window has no bonding. Whether that is okay, I do not know. In this context, it would be interesting to know exactly how the window lintel is designed.