Designing Party Floors to pass Sound Insulation Testing

Designing Party Floors to pass Sound Insulation Testing

This article focuses on the basics of good acoustic design for improving the soundproofing in party floors in dwellings, to achieve compliance with Part E of Building Regulations to attain building control sign off for floors between flats.


The importance of adequate sound proofing in Party Floors.

Undertaking adequate soundproofing to party floors to ensure your flat development meets the requirements of Part E of the Building Regulations and passes the precompletion sound testing, is an essential part of modern construction. Achieving good soundproofing on house party-floors and flat separating floors is essential to ensure that future residents are not adversely affected by excess noise from neighbouring residents.

Unfortunately, noise issues due to poor sound insulation in floors is an issue that affects many attached houses and flats and has been made worse in recent years due to the high number of residents changing their carpet finishes to a timber finish. Unfortunately, a timber floor is far more likely to produce extra impact noise due to high heel shoes, washing machines and chair movement etc. as it’s a hard surface. Also, airborne noise can greatly increase due to high powered music systems, television sets with sound bars, speakers, gaming stations and modern music production equipment.




Excess noise through shared floors can be debilitating for all residents and nobody wants to pay for a new property (or rental unit) only to hear their neighbour’s speech, television or music through poorly soundproofed floors.

When undertaking a new build development or conversion project, it is important to be aware of the sound insulation requirements of Part E of the Building Regulations for party floors, and achieve the required sound insulation levels are required to show compliance with the regulations.

To comply with Approved Document E, soundproofing measures should not be designed merely to ‘pass a party floor sound test’, because if a development just passes, then this means that the properties separating party-floor has acceptable, but not great soundproofing. This can be a huge problem if you a renting out your property, as your new resident may be noise sensitive and because of the excess noise, may only rent for a short period. Also, with the advent of social media you may also receive negative reviews of the property, which may affect future rentals of the property.


We can help with your party floor design.

We work with hundreds of builders, architects and property developers across London and the UK helping them with the acoustic design of the party floors within their developments. Consequently, we are well placed to understand the challenges that sound proofing party-floors poses to new build and/or conversion projects for every type of floor, whether it be concrete, timber, or metal joist we can find a solution to achieve compliance with approved document E.  Therefore, we thought we would produce an acoustic design article to assist those responsible for designing or constructing party-floors or separating floors.


Reasons for party floor sound test failure

Problems with excess airborne and impact structure borne sound are often associated both with direct transmission through a floor and flanking noise transmission via supporting walls and other associated structures. It is essential to establish if your problem is due to direct transmission, flanking transmission, or a combination of so that the most effective remedial treatment can be chosen.



To improve airborne sound, acoustic insulation can be added be installed between joists, its best to use a high mass RW60 acoustic insulation (minimum pass of 60kg/m3) then Install an acoustic resilient frame below the plasterboard. To the underside of the resilient frame add two layers of lapped sound board. Fill all plasterboard joints with acoustic mastic. To improve impact sound its best to install a high quality bonded acoustic resilient mat to the floor, this placed below the floor finishes.


Watch out for Flanking transmission through Party Floors.

Flanking sound transmission occurs when sound is transmitted from one space to another indirectly, through adjoining parts of the structure. For example, impact sound may be transmitted from one room to another through a timber floor, but also through the supporting wall. This can be as simple as the wall has been built straight off the top of the timber floor finish, so the noise travellers along the timber floor and under the party wall from unit to unit.

Flanking noise transmission is always a potential problem within any structure buildings being converted and depending on the intensity of the acoustic energy received via flanking transmission paths, the effectiveness of sound insulation of separating partitions can be much lower than expected from their construction. We often carried out precompletion sound testing to wall partitions that should have achieved around 50dB, but only achieved 40dB, resulting in sound insulation test failure.




Therefore, careful consideration must be given to the effect of flanking noise transmission within party floors within new and conversion projects, and all potential flanking paths must be identified and eliminated prior to the installation of any sound insulation system.

Another common issue that often get overlooked is the filling of air leakage paths. If air can escape through gaps, sound will follow the same path. Therefore, providing an air-tight seal should be given high priority, so sealing all air gaps is important and should be carried out whenever possible.


We can help with the acoustic design and sound testing to your party floors.

APT Sound Testing can provide telephone advice, quote to undertake an acoustic design review of your architect’s drawings to help the likelihood of passing the sound insulation test at the first attempt, reducing the risk of costly remedial works to your project prior to handover. If you require sound insulation testing to party floors, or you need an acoustic design review on your development, please contact us now or visit our acoustic design page.

For further advice on Sound Insulation Testing across the London and the UK, contact APT Sound Testing. Call our expert acoustic consultants today on 01525 303905 or email us at for friendly advice about building party floors and floors and/or sound insulation testing on your construction project.