Yes, it looks like we will get an expert involved for this issue, as we don't trust the matter with the re-concreted step... however, without this step one would run into the chimney after 30 cm - also not a solution. We will meet on site next week - we would actually like to insist on moving the chimney. However, the builder already said that this is not technically possible. But I suspect he does not want the extra work and says this for that reason. He has not justified his statement so far - maybe he will still do so. Is a chimney not allowed to be next to a wooden staircase? Can't one drill a new hole through the ceiling and then raise the chimney there? Then close the hole at the old location? I mean, if you can concretrate a step afterwards, then you should also be able to close a hole again, right? Does the roof then have to be completely uncovered and re-roofed? etc.... I don't imagine this is easy - but it should be doable, or am I wrong here? For us, that would be the best solution... possibly we might even give up on that completely and look for alternatives regarding a cozy fire. But even then the holes must be closed again... Regarding the bathroom, I'm not sure if this is possible since the pipes are planned here and holes have been left accordingly. But the idea is worth considering. At the moment we still feel left alone and only get alternatives that we ourselves have proposed... but this will surely improve next week...