Cost comparison between a duplex and a single-family house realistic?

Well, first of all, thanks for the feedback. I do know the content of the other house. This is only about the stated costs for the one wall, since that amounts to a total of 23,000 EUR.

Content of the house?
I am talking about the construction specification, not the equipment. You certainly have not compared them 1:1.

Our general contractor has, for example, a different construction specification for a semi-detached house than for a city villa or a studio house.

Brief regards

I also think that you cannot simply compare two different construction companies. The descriptions of the building services must be compared very precisely, everyone will use different products (sanitary, interior doors, roller shutters, tiles, etc.), possibly also different wall construction, different roof pitch, etc.

Best regards
Sabine

I also think that you can't just compare two different construction companies like that. ...

Both projects involve the same company

Best regards in brief

Well, then you can quite well compare that with each other.

Best regards
Sabine

I have compared both offers with each other. But for me, it’s not about the other positions here, it’s only about the additional costs for the one side of the house. By the way, there are still massive differences regarding what is already included in the base price for the friends and what is not included for us. This is completely excluded here.

Load-bearing interior walls mostly in 24 cm instead of 17.5 cm €3,600.00

Already a difference due to the typical underlying different construction service descriptions between you and the semi-detached house.

Otherwise, apart from the window issue, his additional items for the semi-detached house/single-family house do make sense; although it was probably rounded up quite generously to make it a bit more plausible to you.

Have you already signed???