Sorry if this is repeating a common thread. We have recently purchased a new build detached house and noticing airborn noise between the upstairs and downstairs rooms. We also have a lot of joist movement noise, but the builders are coming back in a few weeks to remedy this by installing noggings. The ceiling / floor joists are engineered timber joists with chipboard above and 15mm regular plasterboard below. Nothing inbetween, just air. As they are going to be ripping up the upstairs