Understanding the new Part E Building Regulations
The results of unwanted noise – from mild irritation to severe stress – have a detrimental effect on people’s health and their quality of life.
This is particularly bad in homes and apartment blocks where the scale of noise has increased dramatically in recent years to become one of the 21st century’s biggest environmental and building problems. At a time when the construction industry is being encouraged to build to greater housing densities, this issue is even more significant.
To combat the current noise pollution problems the Government has introduced new legislation. These new standards have been published in the new Approved Document – Part E (England and Wales) of the Building Regulations ‘Resistance to the passage of Sound’, which came into effect on 21st January 2004 for new build and 1st July 2003 for refurbishment.
The Government is tackling the problem by introducing more robust building standards to improve soundproofing in new homes and schools – both new build and refurbishment projects – in England and Wales (Part E).
The aims of the Part E legislation are to:
The table below summarises the acoustic regulations as published in Part E 2003 Building Regulations ‘Resistance to the Passage of Sound’:
For the first time, pre-completion testing is being enforced to ensure that buildings meet the Part E standards.
The only exception to the regulation is where the building conforms to a Robust Standard Detail (RSD) document, which contains details of those constructions that perform consistently well and do not require on-site testing.The Regulations state that one in ten of each construction type requires testing (selected at the Building Inspector’s discretion). If a failure occurs, then the construction will need to be improved and re-tested.
Each building environment is unique and there are many variables that can impact on the acoustic performance, such as workmanship, services, existing structure and other external factors.
Therefore specifiers should be mindful of these issues when selecting an acoustic construction type and it is worth noting that small defects in the build can significantly affect the overall acoustic performance.
REMEMBER an acoustic construction will only ever be as good as its weakest link.
DEFINITION OF TERMS
Additional helpful information
When attempting to make any sort of construction compliant to the Part E Regulations it is important to note that sound does not always go straight through a building element. If the wall/floor/partition concerned is well acoustically insulated, then sound will simply go up and over or around the sides. This is called ‘flanking transmission’ and it occurs when sound travels along elements shared by adjacent structures.
If flanking constructions are not correctly specified or constructed, flanking transmission can exceed direct transmission and seriously reduce the overall capabilities of the construction. The best way to deal with this issue is to use resilient neoprene-type ‘flanking’ strips at the top and bottom of every wall and around the edges of floors as well as using an acoustic sealant wherever possible.
Ctr Adjusting Factor
The +Ctr factor varies according to the construction and can result in the original Rw dB value being reduced by up to 13dB. This impact on resulting solutions is critical in meeting the required Standards:
To ensure maximum performance from a soundproof structure, it is vital that great care is taken in its construction. It must be built as if it needed to be waterproof, since sound, like water, light and air, will find the smallest crack or hole and expose it as a structural weakness.
Any hole or gap will significantly reduce acoustic performance. A single 25mm hole can reduce performance by up to a massive 15dB which may render the structure acoustically useless.
Although a 25mm hole would be visible, a crack 1mm x 1m will not always be obvious, and if not treated with an acoustic sealant it will be extremely detrimental to the acoustic performance.
The acoustic performance of any tested acoustic structure may vary on site so it is always advisable to choose a solution that exceeds the acoustic requirement (by around 10dB) to limit the potential impact of any site variances.