ᐅ Installation of Interior Window Sill, Especially in Drywall Construction

Hello everyone,

I have some questions about interior window sills, specifically in drywall construction:

1.) How are interior window sills installed in drywall construction? Are they fixed with foam?
2.) Are there technical reasons why interior window sills are mostly installed like the left option in the sketch? At least that’s what I have seen as a layperson. It probably has to do with traditional plastering, since plastering is done after the window sill is installed.
3.) Or is there complete flexibility with drywall, and it can be done according to personal preference? Does anyone have pictures of the right option?

Thank you very much

1.
There is special mortar designed for granite or stone window sills.

Wood is either glued or screwed in place.

2 and 3.
For simplicity, when plastering, if the window is 120 cm (47 inches) wide, you use a 120 cm (47 inches) wide window sill. After that, plastering is done, and on each side, depending on the window frame width, 1 to 3 cm (0.4 to 1.2 inches) of plaster is applied. This results in the window sill being built into the wall. Otherwise, it needs to be clear beforehand how far the plaster will extend.

In drywall construction, the window sill is simply glued between the drywall reveals, so there is no overhang. Creating an overhang in drywall would be too complex.

Since I received a message from an admin stating that images from external servers are not allowed, I have uploaded them again directly. The last attempt unfortunately showed an error in the preview.

Does anyone happen to have pictures of the different installation methods, especially for drywall construction or prefabricated houses?