Thanks all.
I wonder if you could help advise those of us living in properties with this issue?
I moved in after the 2 year initial NHBC warranty period. Can anything be done to fix after the fact?
The NHBC mentions this issue in their technical summary dated 2013, but there are lots of caveats.
It's depressing, and the new-build builders are awful (Taylor Wimpey in this case), as are the politicians who don't ensure basic rights are in place. I'm suffering from both footfall and cracking noises from upstairs (who have hard floors of some kind installed). The lease mentions floor covering but it is vague (doesn't say, for example, for X% to be carpeted). My flat is carpeted for some reason.