I did this a few years back in an attic. I did the floor and the partition only. I put 2 layers of 15mm sound damping PB then have a 20 mm air gap then 75mm of sound insulation then another air gap and Finally another 2 layers of SDPB. I built a floating floor on isolation mounts and 100mm insulation went in there as well. Made an air tight door with 30mm mdf and its completely silent now and doesn't pull heat from the house in winter. Hopefully you don't get a load of banana timbers or framing gets more interesting.
If i didnt smoke i drink myself to death.
Bookmarks