| Building Element |
Walls, floors and roofs etc. |
 |
| Ctr |
The correction to a sound insulation quantity to take into account low frequency noise. |
 |
| Decibel (dB) |
The most commonly used unit to measure sound. |
 |
| DnT,w |
The measurement used to measure the airborne sound insulation between two rooms (on site). |
 |
| DnT,w+Ctr |
See above, but with the low frequency correction factor included. |
 |
| Flanking Transmission |
Sound transmitted between two rooms using an indirect path i.e the
top or bottom of a separating wall (see further details below). |
 |
| Frequency |
The number of pressure variations per second that gives a sound its distinctive tone. |
 |
| Hertz (Hz) |
The unit of the frequency of the sound. |
 |
| Impact Sound |
Sound resulting from direct impact on a building element. |
 |
| Internal Floor |
Any floor that is not a separating floor. |
 |
| Internal Wall |
Any wall that does not have a separation function. |
 |
| L’nT,w |
The measurement used to measure the impact sound insulation of floors (on site). Lnw = laboratory testing |
 |
| ∆Lw |
Denotes the measured improvement of impact sound insulation resulting from the installation of a floor covering or floating floor. |
 |
| Pre-Completion Testing (PCT) |
A requirement introduced under Building Regulations (england and Wales) Part E Requirement E1 (2003) for sample testing of separating elements in order to show compliance with the regulations. |
 |
| Robust Detail (rd) |
A form of construction published in the Robust Details Part E Handbook that has been approved by
Robust Details Ltd for use as an alternative means of compliance with Building Regulations (England
and Wales) Part E Requirement E1, including the possible exemption from PCT – when plots are registered with Robust Details Ltd, for completely new build attached dwellings. |
 |
| Rw |
The measurement used to rate the sound insulation of a material or building element in a Laboratory. |
 |
| Separating Floor |
Floor that separates flats or rooms for residential purposes. |
 |
| Separating Wall |
Wall that separates adjoining dwellings, houses, flats or rooms. |
 |
| Sound Reduction index (SRI) |
A quantity measured in a laboratory that characterises the sound insulation properties of a material or
building element in a stated frequency band. |
 |