I'll start building my studio very soon

I would like to make sure I'm not doing anything that would compromise ceiling's insulation(like a triple leaf).
I'm going to build the studio (room within a room) in the ground floor.
The studio's ceiling is made of 2 layers of 12.5mm Fermacell (drywall).
It will be held to the joist using resilient channel (Rigips).
Between the studio's joist, I'll add rockwool (8cm)
The room above is equipped with an underfloor heating system sandwiched between 2 OSB layers and then the floating parquet.
Here's a schema of what I'm trying to explain.
Is this ok or am I doing something wrong?
Thanks in advance for your help.