Dimensioning of floor-to-ceiling windows in the floor plan?

It could be that measurements are taken from OKRFB. Otherwise, there would be inconsistencies compared to the specification of the window sill height of the other non-floor-to-ceiling windows, which are measured from OKRFB.
246 cm minus 20 cm floor construction results in a clear window dimension of 226 cm. This leaves 24 cm for the roller shutter box and lintel up to the clear ceiling height of 2.50 m.
But this also means that the specified 246 cm would be excluding the roller shutter box.

Regards

Hi. You have a misconception: The 246cm includes the [Rollladenkasten], as it has to fit into the window opening. The remaining 24cm will then be filled by the lintel. Roughly, the window will probably be 206cm high plus ~20cm [Rollladenkasten].

So, now I’ll bring some clarity after consulting with the planner:
"...Measurement always from the top edge of the window frame to the bottom edge of the beam."
The window height of 206 cm fits when the roller shutter box is above it (attached roller shutter box on the window).
From your perspective, would a front-mounted roller shutter box provide a larger window area? 206 cm is not particularly much. The masonry is planned with 20 cm sand-lime brick + 16 cm ETICS.
Does anyone have experience with the different roller shutter boxes, also regarding insulation values?
Best regards to everyone.
Ippebson