Until when is smoking tolerated in the new building?

It still doesn't hurt to treat people like human beings. If a good place to sit is available, it is just normal and fair on a human level to make it as comfortable as possible for the people. They are there full-time on the construction site and appreciate something like that. Of course, it's not a must, but it doesn't cost you anything either.

It doesn't hurt to treat people like humans anyway. If a good place to sit is available, then it is only normal and fair on an interpersonal level to make things as comfortable as possible for the people. They are there full-time on the construction site and appreciate something like that.

I was talking about a female client, not a construction dominatrix or construction slave driver, so I assume the interpretation of the term mistress as kind, fair, polite, etc. – but certainly not submissive. If the floor is already being used as an ashtray, it's time for a clear message.

Of course it is not mandatory, but it doesn't hurt either.

However, smoking in other people's rooms only after explicitly confirmed permission, but also not.

Legally, the house belongs to the builder until handover?

From a purely legal standpoint, yes. Legally, he could also install a different railing than the one we like. But for the sake of simplicity, let's just assume that he is a contractor who wants satisfied customers.

Legally, the house belongs to the builder until handover, doesn't it?

Only if you buy from the property developer. In the case of construction by a general contractor or individual contracts, everything that is permanently connected belongs to the landowner. Even without payment or acceptance.

No, he has to install the railing that is specified in the contract.

As long as the cigarette butts are swept away before handover, I don’t see any reason to make a fuss.

If floors were laid and walls painted/wallpapered, that might be a different matter. But even then, you can hardly get an experienced painter to stop smoking at work.

As a confessed non-smoker, you can quickly ruin it for yourself. And then have fun ;)