ᐅ Insulation, frost-protected attic space, controlled mechanical ventilation, heated attic

Hello everyone,

I need some advice from you.

Originally, we planned not to insulate our attic space, only the ceiling of the top floor. Since I am having a controlled ventilation system installed, it needs to be placed in a frost-free area. Therefore, I have to change the insulation plan.
After consulting with our construction manager, he recommends insulating the entire roof now, and to prevent the attic from being overheated, also insulating the ceiling of the top floor.
Is this approach okay, or will the insulated ceiling prevent enough heat from reaching the attic later on?

Hello

We also used double insulation, so there is already a noticeable temperature difference. However, if I decide to renovate the floor later, it is already insulated and sealed with a vapor barrier. I don’t want to deal with glass wool inside the house again.

Best regards, Sven