Full floor or with knee wall?

Hello everyone,
I have newly registered because I have a question.

We are currently deep in the planning of our single-family house and now the question arises whether we should build two full floors or have a knee wall of 1.90 m upstairs.
Our shell builder said it is cheaper with two full floors because the roof structure does not have to be insulated and the ceilings do not have to be dropped in the first floor.

Does anyone of you have experience with what is cheaper?
From a purely practical point of view, two full floors would be better.

Best regards, Julia

If you may, then do it instead of the 1.90. You could also juggle windows better and put up cabinets.

Your shell builder is a clever man. No one builds a 1.90 knee wall.

Yes, according to the authorities we are allowed to build two full stories with a maximum of 6.5 meters.

We thought it would be cheaper with the knee wall and then we wanted to put some narrow light entry windows at the front like you see everywhere now. But he said yesterday it probably comes cheaper with the two full stories without the knee wall. I was now unsure whether it would really exceed our budget in the end. We are somewhat limited by the costs and the first thought was: "bigger house" = "more costs". But according to the shell builder, that is not the case.

Your shell builder is a clever man.
No one builds a 1.90 knee wall.

Then take a look at Rensch-Haus, they have something like that.

I was unsure whether it would really exceed our budget in the end. We are somewhat limited by costs and the first thought was: "bigger house" = "more costs". But according to the shell builder, that is not the case.

Then introduce your house to us in the sub-forum Floor Plan Discussions: maybe we can find ways to save. This often concerns the driveway, well-used living space, combining rooms or pipes, etc.