gristle
Senior Member
This isn't a bad thing if it's done well. Done well = at least 3 layers of type x 5/8" GWB - preferrably 4 layers (2 each side), with roxul insulation between. Even better is two parallel walls with alternating studs.
And that is the key! The builder can always go for minimum code, along with the maximum allowable level of through-wall noise transmission.