Insulate the ceiling with drywall / composite drywall?

Hello everyone,

I want to improve the insulation in a condominium towards the roof.

My room ceiling is a simple drywall board, followed by a wooden stud frame, foil, and insulation wool of unknown thickness above that. Then there is a folded copper roof.

I often have the feeling that a lot of heating energy is wasted here. Now I want to screw another drywall board onto the existing one as part of a renovation. Either 12.5mm drywall or composite drywall. With this, I want to improve the insulation upwards.

An attic conversion, i.e., additional insulation from above, is not an option. You simply cannot get there.

What benefits does this measure bring me? Are the costs reasonably justified by the benefits?

Regards

Manuel

Enter the values into the U-value calculator. Rigips is not an insulating material. In a composite panel, only the Styrofoam part insulates, and what are 1-2 cm anyway? More sensible but also more expensive would be a vacuum insulation panel, but then no nail is allowed in the ceiling anymore. However, it insulates very well and is lightweight, and 20 mm is enough (enter the values into the U-value calculator again).