Part E Explained

What is Part E?

The term “Part E” refers to the new Approved Document E of the Building Regulations. Part E came into effect on 1 July 2003 and details new acoustic performance requirements in England and Wales for residential dwellings, schools and other construction types. Along with new performance requirements, Part E also establishes a need for Pre-Completion Testing to enforce these standards and suggests a range of constructions for appropriate elements. The key elements for residential dwellings are separating walls and floors between dwellings and internal partitions within dwellings. Both new build dwellings and those new dwellings created by what Part E describes as “Material Change of Use” are covered. Material Change of Use relates to what would be more commonly known as refurbishment and conversion work.

The information provided here applies to dwellings.
For advice on other constructions, including schools, please contact the Key to Part E Customer Hotline – 0870 240 6371.

Why are there new standards in Part E necessary?

Significant attention is now being paid to the issue of unwanted noise transmission within buildings and, in particular, to noise transmission within residential dwellings. The new standards in Part E are designed to improve modern living standards.

When does Part E come into force?

For the Material Change of Use market the Part E regulations apply from 1 July 2003, whilst for New Builds the impact of Part E has effectively been deferred with Pre-Completion Testing now not required until 1 July 2004.

Tables 0.1 and 0.2 show the new acoustic standards, where they apply and when Pre-Completion Testing will be required from.

Table 0.1

Dwelling Houses & Flats
Separating walls, floors and stairs
Date Pre-completion
testing applies
New Build Airbourne sound insulation
DnT,w + Ctr dB
(Minimum values)
Impact sound insulation
L'nT,w dB
(Maximum values)
1 July 2004
Walls 45 -
Floors 45 62
Material Change of Use 1 July 2003
Walls 43 -
Floors 43 64

Table 0.2

Laboratory values for internal walls and floors
Airbourne sound insulation
Rw dB (Minimum values)
New Build
Walls 40
Floors 40
Material change of use
Walls 40
Floors 40


dB (Decibel) indicates the level of sound reduction required.
Rw laboratory measurement of airbourne sound transmission.
DnT,w + Ctr site measurement of airbourne sound with low frequency correction applied.
The higher the figure the better the performance.
L'nT,w site measurement of the impact sound level.
The lower the figure the better the performance.

Do I need to build using the suggested construction in Part E to comply?

The constructions suggested in Part E are merely examples and, as stated, not exhaustive.

Section 0 of the Approved Document, paragraph 0.5 states:

“Sections 2,3,4 and 6 of this approved document give examples of constructions, which, if built correctly, should achieve the sound insulation values for dwelling-houses and flats set out in Table 1a, and the values for rooms for residential purposes set out in Table 1b. The guidance in these sections is not exhaustive and other designs, materials or products may be used to achieve the required performance”

If you choose to build to these constructions you will still need to Pre-Completion Test.

Written by Stephen Young

© Sound Service (Oxford) Ltd. 2004


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