Below are the revised Sound Insulation Performance metrics required from July 1st. 2015.

July 1st. 2015 sees the requirements of The Building Regulations increased with regard to sound insulation metrics, which must be achieved and proven by acoustic testing on-site prior to certification of the dwelling property.
See the revised Standards which must be achieved in Table 1 below.

Sound Performance Levels – Required from 1st. July 2015 – TGD Section E
Separating Construction
Airborne Sound Insulation DnT,w dB
Impact Sound Insulation LnT,w dB
Walls 53 (Min)
Floors – (incl. stairs with a separating function) 53 (Min) 58 (Max)

Table 1 – Showing revised levels / metrics to be achieved for sound testing from 01/01/2015


The significant difference between the levels indicated in Table 1 above and those required previously by TGD Section E 1997 is the removal of the allowance for unfavourable deviations in test results.

Previously you could carry out 4 tests or more and provided that the mean average of all 4 or more tests achieved 53dB for airborne to walls, (52dB for airborne to floors or 61dB for impact to floors), with no individual unfavourable sound test result being greater than 4 dB away from the required average you may be deemed to meet the criteria of reasonable sound insulation. This is no longer the case!

  • Now every individual test result must achieve the stated metric for wall or floor type!
  • Now Impact Tests are more stringent by 3dB and also include a separating stairs!