Additional floor... Liability insurance for damages?

Hello everyone! I am currently building an additional floor as a residential unit on my parents' house. The construction management is done by the architect. Construction began in February. Although it was raining heavily at that time and we expressed concerns about starting construction, the shell construction still began. The house has 6 units, that is the ground floor, 1st and 2nd upper floors. When the roof opening for the staircase was made, standing and dirty water ran from the roof down all the walls to the ground floor. A complete renovation of the staircase is now necessary. My question: shouldn't precautions have been taken before the roof opening to prevent the entire staircase from being affected? The floor below... okay, but all three floors? Also, the open roof was not protected against rain and in two apartments on the 2nd upper floor water penetrated and the tenants demand removal of the water stains. Whose liability insurance covers this? Regards Evamaria

Is there anything contractual about how the still inhabited units are to be protected from the construction? Have you noted the concerns in writing?

I’m afraid you have to first repair the water stains and the stairwell at your own expense and then try to sue for reimbursement. But if there is nothing in writing regarding covering the stairwell, I don’t see how you’d get any money back.

Is there anything contractual about how the still inhabited units are to be protected from the construction? Have you noted the concerns in writing?

I’m afraid you first have to renovate the water stains and the staircase at your own expense and then try to sue for it. But if there is nothing in writing about covering the staircase, then I don’t see that you will get any money back.

I feared so. Thanks for the information

No, there is nothing contractual and we have only expressed the concerns verbally. I feared that the costs would be borne by us. Thank you for the info!

the concerns were only expressed verbally.

But at least in front of witnesses, I hope.

The construction management is done by the architect.

So a coordinating authority "above" the involved craftsmen, the scaffolder, etc. There should be something like "good faith" in "recognized rules of technology" to hold the architect’s professional liability insurance accountable. Professionally, he must have been aware of the temporary vulnerability the measures would cause for the existing building. A lawyer experienced in construction contract law should find ways to hold the expert liable for his negligence. After all, you didn’t do this for fun with Karljosef's brother-in-law's buddy, but with an expert. So I don’t think you have to explicitly explain in writing to an architect what a roof can do only while it exists, and that rain is wet and typically comes from above.

Only legal recourse. Is the damage very severe? Is it worth suing or can the craftsmen manage it?