Window: Frame widening at the top

Hello,

for an outbuilding, I have window openings of 1250x1750mm (width x height) in 24 cm masonry in the shell construction. The openings are flush with the ceiling, so without an additional lintel. I took over the building like this. Now I want to install windows but without roller shutters; however, I want to suspend the ceiling inside, possibly with attachments from above, so that a tilt-and-turn window is not possible up to the ceiling. Option frame extension at the top (100mm).

How do I plaster the outside to create a uniform reveal, including the sides? For the interior, one can certainly work with drywall...?

Hello,

I see no concerns here that it cannot be plastered cleanly and evenly. The doubling is usually done with window profiles, so the frame simply becomes stronger or higher.

The doubling can be omitted if you have a piece of panel installed at the top. Assuming 250mm here, you would have a clear opening of 1250x1500mm as a "window." This also gives you a lot of leeway regarding the height of the suspension.

There is another option: divide the window as above, but install a darkened glass pane.