We were not able to renegotiate anything, even the smallest changes were specified down to cents and euros.
Change to the windows per window 17.85 euros something like that
We did not negotiate because the price seemed fair to us. However, we did not pay any additional charges for extra windows or for enlarging them from 1.80 to 2.00 meters in width or from 80 to 100 cm in width. Also, an asymmetrical window was additionally included at no extra cost. We had many €0 items in our invoice.