I took the liberty of searching for Evolith's draft and posting it here.
Compact hallway, 3 bedrooms included in just under 170 sqm...
And nobody here has to say that 170,000 for 130 sqm is not tight,
Just as little as 4 rooms plus living-dining are tight on 130 sqm when the hallways are to be designed barrier-free.
Not everywhere are there Brandenburg conditions.
Even though Lower Saxony is already quite affordable as standard - barrier-free is simply not a standard.
You should actually consider how (even if with the house price and on 130 sqm everything could now be implemented) to reconcile the rooms with your family planning. Are 3 children then supposed to sleep in the one children's room?
Or do you want, once the house is finished, to immediately start expanding the upper floor and thus install the staircase?
Then you might as well install it right away, right?