ᐅ Ceiling insulation in a loft apartment

Hello everyone,

In the living room of my attic apartment, I have beams with wooden boards on top as the ceiling.
I find it visually very appealing, but the insulation is basically nonexistent.
I would like to place polystyrene boards between the beams and then install drywall panels on top, so that some of the wooden beams would still be visible.
Would it be sufficient to use 40mm (1.6 inches) thick polystyrene boards, then 12.5mm (0.5 inches) thick drywall panels, sealing the edges next to the wooden beams with acrylic?
This way, I would have some insulation.

Or is there perhaps the option to insulate from above, meaning placing insulation material in the loft space or something similar?

Regards

It is possible, but in my opinion, it offers too little benefit because there are many thermal bridges, and the polystyrene insulation is not the best insulator. If the current appearance is important to you, then adding insulation to the upper floor makes sense. A layer of insulation is then applied across the ceiling. It is important that this is properly sealed.

Is the roof above not insulated?