Construction costs for a single-family house with a basement in NRW

7
So you consider 1556 times 140 sqm = approx. 217k reasonable for the house.
Am I seeing that correctly?

No. I was referring to the posted link (listing), minus assumed land and ancillary construction costs. This leaves a price of approximately €260,000 for the offered terraced house. Considering what is stated in the listing regarding the construction method and features, I find the offer reasonable.