Parapet height window difference OKRFB upper edge of finished floor

Hello,
we received the execution drawings to sign yesterday. They also seem to be okay, but I am having trouble understanding the parapet heights and will therefore contact the site manager tomorrow. Nevertheless, I am already curious today.

In the plans it says "Parapet height information is from OKRFB". In the kitchen, a height of 1.035 is shown; we had specified 90cm there because our kitchen countertop is supposed to run into the window as a window sill replacement.
The plans show 0.5cm for the sealing, 10.0cm of loose fill insulation, 6.5cm screed, and 1.5cm covering. The 18.5cm should be the difference between parapet height OKRFB and top of finished floor, shouldn’t it?

If that is the case, then our 90cm height for the underside of the countertop no longer fits, and the parapets of the other windows seem very low at 81.5cm as well. We now live in a 2-year-old new building, where the underside of the window sill is at about 90cm, thus 8cm higher.

Is there an error in the planning or is the error on my side?

Thank you

RFB should actually be on the screed, so you are right, and there must be an error here.

Regards

I just spoke with the site manager, they assumed 90cm from the top edge of the countertop, we specified the 90cm to be from the underside. This will be adjusted and then it will be correct.