Sound insulating a party wall

[aidf72]

In one room of my house I'd like to remove the plasterboard on the party wall, add some Knauff insulation panels and put back a double thickness of plasterboard. Are there any regulations preventing me doing this? and do I treat the two layers as one, and screw them with longer screws? or do I screw one on and then the other?
Thanks.

 

[noseall]

there are no regulations preventing this that I'm aware of.

fix one layer then stagger the joints on the next layer. you will obviously nee to buy a wider door casing too (where applicable).