Wall niche in load-bearing wall - reversible?

Right upfront: I am not a structural engineer!

Personally, if I understand your description correctly, I would leave the niche.

After all, the wall is not completely cut through and thus still contributes somewhat to the structural integrity. If you want to be 100% sure, there's no avoiding a structural engineer.

You can also install a lintel =D you can get one at the hardware store for a few euros, maybe then you’ll feel better about it.

Cheers

How thick were the bricks before the chipping work?

#1, 36cm with plaster 40cm, I think the reduction by 1/3 is included in the safety of a load-bearing wall, estimated not as a structural engineer, with rule of thumb. If no cracks have formed starting from the niche

I think the reduction by 1/3 is included in the safety of a load-bearing wall, not estimated by a structural engineer,

As a non-structural engineer myself, I still lack the facts here to at least be able to estimate seriously. In normal or thin format, this should be taken less lightly than in jumbo formats.

Thank you. On Saturday we had a bricklayer here, who indirectly is also involved with the topic of statics and also thinks that it’s not a problem. I also thought of a lintel, but the problem is that the boxes + wiring for the lighting are already installed at the top of the niche (niche is in the bathroom) and a subsequent lintel would cover everything up

As a non-structural engineer myself, I still lack the facts here to at least be able to make a serious estimate. In normal or thin format, this should not be taken as lightly as in the jumbo formats.

Thank you for your note. I cannot say the exact brick format right now, but it is certainly not DF or NF, I think.