It’s extremely important that careful consideration is given to the acoustic design for pre-completion sound testing at an early stage of the design and construction process. It can be very problematic if the building fails the pre-completion sound testing just before buildings due to hand over.   To try and reduce the chance of a sound test failure APT can visit site to conduct a comprehensive acoustic design survey and  review. We also take this opportunity to meet; the site/project manager, architects etc. to go through the building’s design, site constraints and most cost effective method of achieving Part E of Building Regulations.

Our proactive acoustic design service, takes into account the build-ability, programme time and material cost. We ensure the relevant parties are fully aware of the installation detail required, highlighting possible ‘onsite’ construction problems and their prevention to achieve a successful installation and building sign off.


Once we have completed the acoustic design report our services don’t finish there. We provide the site team with on-going design support. You will have direct contact with the allocated acoustician from the start of the process through to the successful completion of the project.

Once the part of the building is completed we can undertake sample sound testing to ensure the design and onsite construction methods are sufficient to achieve a Part E sound test compliance.


Unfortunately, it is very difficult to construct acoustic details to the stringent standards of the laboratory. When the construction assembly is tested in the lab, it is also certified and an exact description of the materials and the installation techniques are described in detail and followed to the letter, obviously this should be replicated on the your site as closely as possible. However, it is not always possible to replicate the exact conditions on the job-site compared to the ideal conditions normally present in a lab setting, which is the reason why a 5dB point difference is allowed between the construction design on paper and the actual on site construction performance.


To try and work out if you have flanking sound you first need to understand how the sound is travelling into your home. It may be coming directly through the separating partition, i.e. wall or floor or it may be coming along another indirect route – called a flanking path. The most common such flanking path is the inner leaf of an external cavity wall.

Problems with airborne and structure borne sound are often associated with direct flanking transmissions through floors and 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 both so that the most effective remedial treatment can be chosen. If you are unsure where the sound is getting through, then contact us as we should be able to identify the worst areas by undertaking sound testing on the problematic partitions.


Unwanted noise travelling along flanking paths makes the building structure vibrate and this causes the sound to radiate into your room. One solution is to build another wall or ceiling in front of the original, but not connected to it (often called an independent wall or ceiling). APT can help to locate the flanking sound and propose a cost effective design that will satisfy Part E of Building Regulations.

If you would like more information in regards to sound testing please also follow our blog at:, or contact us at: or phone us on 07775623464 or visit our website at:



Here at APT Sound Testing our clients often ask for a summary of our sound testing and noise survey services we undertake in compliance with Part E of Building Regulations . Here is a quick summary of our acoustic services:

We are UKAS accredited to carry out Sound Insulation testing for:

  • Houses and flats in compliance with Part E of the Building Regulations.
  • Houses & Flats in compliance with the Code for Sustainable Homes.
  • Classrooms within schools in compliance with BB93.
  • All commercial buildings in compliance with BREEAM.

We also carry out carryout various noise surveys to comply with the following:

  • Noise Surveys 8233 for Planning Applications.
  • Background Noise Surveys for Air Conditioning Plant.
  • Industrial Noise Surveys

The sound insulation levels required to pass Part E are usually 45dB for airborne wall and floors and 62dB for Impact Sound Testing on new build and 43dB for airborne wall and floors and 64dB for Impact for converted properties. Sometimes a higher target may be required in-line with the Code for Sustainable Homes; this is usually in defined in the following figures +3, 5 & 8dB. Obviously if you need to comply with the Code then special attention must be shown to the acoustic design from the offset. APT Sound Testing can help you to achieve this more robust design criteria. We can also help if your building fails the sound insulation testing by offering a targeted acoustic design solution saving time and potential costs.

sound testing

The amount of sound testing you require depends on the size of the development. All new build properties and conversions require 10% of each party wall/floor construction type to be tested, i.e. if you have 10 flats you would require 1 x 6 pack, this consists of 2 airborne wall, 2 airborne floor & 2 Impact sound tests. However if you have 11 units this would rise to 12 Sound Tests or 2 x 6 pack. Sometimes more tests may be required if you have many different types of walls and floors, however we will always try to propose the minimum testing required to comply with Part E.

Impact Sound Testing

We also offer planning noise surveys comply with BS8233 and BS4142, this allows us to provide all you acoustic requirements in one easy package; reducing cost and improving onsite co-ordination. Air Pressure Testing is UKAS accredited to undertake both Sound and Air Tightness Testing and is also accredited to ISO 17025:2005 ‘General requirements for the competence of testing and calibration laboratories’

 If you have a project that requires sound insulation testing and you are unsure how to comply with Part E of Building Regulations then contact us now, we can propose a sound testing schedule that should comply with Part E. If you are unsure of your projects acoustic requirements please click here at; or visit our website at  or call us at 07775623464

Sound Insulation Testing – Questions & Answers.

 Sound Insulation Testing – Questions & Answers.

APT sound testing often get asked a similar bunch of questions in regards to sound insulation testing. Over the last couple of years we have collated these questions and answers and to help our valued clients we have shown these below.

What is sound testing for Part E
Sound Insulation Testing is a method of quantifying the sound insulation performance of  walls and/or floors. Sound testing can be carried out on party walls, party floors or facades of any building.

What is sound insulation?
Sound insulation is the property of a wall and /or dividing partition to resist the passage of noise.

Why do I need sound testing on my Project/Property?
The largest single reason for disputes between neighbours is noise complaints. Approved Document Part E – Resistance to the passage of sound describes minimum standards to be achieved by newly built domestic dwellings.

What building regulation do we work to?

Approved Document Part E, sets out minimum standards for sound insulation performance to be achieved by party wall and party floors. Building contractors may show compliance with Part E of the Building Regulations by two methods. One method is to register plots to be built with Robust Standard Details Limited and the other is to show as-built performance by Pre-Completion Sound Testing to Part E of Building Regulations.

When are Pre-Completion Sound Tests carried out?
Pre completion Sound testing is carried out when the construction of party walls and floors are largely complete. Windows should be in place with any vents closable. Internal and external doors should be in place, along with skirting, cornicing and plug sockets in place. Sound testing on floors must be carried out before any soft coverings are in place.

 Do detached properties require sound testing for Part E of Building Regulations?

No, only attached properties require sound tests, detached properties share no common partitions with any other properties.

Are internal walls/floor between rooms within a single dwelling sound tested?
No, Laboratory test based performance standards (Rw) exist for certain internal walls and floors, but they are not intended to be verified as-built by on site measurement and therefore sound insulation testing is not a requirement.

How many sound tests are needed on my Project?

Approved Document E states that one set of sound tests is required for every 10 units in a group or sub-group. A group or sub-group is defined where significant differences in construction or layout occur, for instance:

  • For a pair of semi-detached Houses – a set of tests would usually comprise two airborne sound insulation tests of a separating wall.
  • For Flats (up to 10 units) – a six pack would normally be required, this comprises of: two airborne wall tests, two airborne floor tests and two impact floor sound tests. The easiest way to work out the number of tests required is to multiply 1 x 6 packs for every 10 flats, i.e. if you have 22 flats you will require 3 x 6 packs which equals 18 sound tests in total.
  • For Rooms for Residential Purposes (student accommodation, hotel rooms, care homes etc.) – a set of tests would usually comprise: one airborne sound insulation tests of a separating wall; one airborne sound insulation test of a separating floor; one impact sound transmission test of a separating floor.

How are plots selected for sound testing?
We will usually specify the sound insulation tests that are required. We first look at the plans then work a testing schedule taking into account testing through both the projects lounges & bedrooms where possible. We will also try and undertake testing across walls and floors in different areas of the building. The building control officer, warranty provider or other concerned parties may require you to carry out sound testing in specific areas or plots. However where this has not been stipulated we can advise accordingly. When we have specified the sound testing schedule it should always be checked by building control and/or the client to seek their approval before the commencement of testing.

How do I Preparing my Site for Sound Insulation Testing?

APT always send out a checklist with our fee proposals to help you prepare for the sound testing, as we always want our clients to be fully prepared so they can pass their sound testing at the first attempt.


Will the sound insulation testing disrupt work on site? 
There should be minimal site disruption during the sound insulation testing. However, although high levels of noise are generated but in order to make accurate test measurements, relatively quiet conditions are needed to take accurate measurements. This means that anyone working in the testing area will have to leave temporarily and any noisy works in the vicinity of the test rooms will need to be halted i.e. using power tools.

How long will the sound testing take?

The time taken for London sound testing varies with site conditions, but generally a ‘6 pack’ set of tests on houses and flats takes about one to two hours. Obviously this depends on the site being fully prepared in line with our sound testing checklist.

How do I know if I’m ready for a sound insulation test?
The plots should be at least at second fix stage – for further details please refer to our checklist.

Do I need all internal and external doors and windows installed?
Yes, all internal and external doors must be fitted and operable prior to the sound testing. Trickle vents must also be installed where required.

 What if I only have 110 volt on site?

Unfortunately we cannot undertake the testing; we will need 240V to undertake the sound insulation testing.

Should I inform my neighbours of the impending sound testing?
If the building is attached in any way to occupied properties then you will need to inform the neighbours. To comply with Part E we need to gain access to the neighbouring properties to undertake the sound test. You will need to ensure that access is provided to the neighbouring properties throughout the sound testing.

Can you offer advice to help me to pass my sound insulation testing?
We offer an acoustic design service to help you design your buildings partitions to pass Part E sound testing. If you send through the relevant drawings such as sections and plans during the design stages of the project, we can check the design to see if there are any junctions or details where ‘noise flanking’ may occur. You can then change your design to lower the chance of a sound test failure.

Do you have a check-list to help us prepare for the sound testing?
Yes, we have an informative checklist to help prepare for the testing, please visit our website at to download the checklist.

Is it easy to upgrade the sound insulation in my Existing Home?.

Yes of course. If excess noise is causing you stress and anxiety, in comparison upgrading the walls/floors to your existing property can be a worthwhile process. its normally quite easy to upgrade walls and floors/ceilings to lower sound transmission. Sometimes it can be as easy as installing an acoustically (insulated) backed board against the offending partition. In all instances it is important not only that the right products are used to cause minimal disruption but they are also fitted correctly in-line with manufacturer’s guidelines. .

Rest Assured

We believe in working with our clients whether they are existing home owners suffering acoustic problems or large developers requiring a more expansive service to achieve sound testing compliance. We believe that by being involved at the beginning of a project we can often save our clients expensive and difficult remedial works at the completion stage of a project.

If you would like more information on our full range of services please contact us now at or call us on 07775 623464


Planning Noise Survey Guidance

This guidance is to assist developers and consultants who are involved in  developments where planning permission is required and noise is a consideration and a noise survey for planning is a planning condition requirement .

At what stage will a noise survey and PPG24 report required?

A noise survey and PPG24 report may be required at the application stage or once planning.

permission has been granted. A noise survey and report are required if:

  • the proposed development with commercial areas that may create noise which may affect nearby noise sensitive properties. For example, a new commercial activity near existing residential properties.
  • the proposed development positioning will be sensitive to noise and is likely to be affected by existing noise sources i.e. busy roads, railway, airports or commercial activity.

What is the PPG24 noise report for?

The PPG24 noise report is to demonstrate that:

  • the source of noise is evaluated and quantified
  • nearby noise sensitive receptors identified
  • noise receptors have been determined with reference to noise standards

The PPG24 noise report (where required) will also set out control measures where it is necessary to reduce noise to acceptable levels. For example, the installation of different glazing e.g. from double to triple glazed panels or acoustic trickle vents are installed so that internal noise standards are met.

sound testing equipment

When should a PPG24 noise report be submitted?

A PPG24 noise survey and report should be submitted during pre-application discussions or

more commonly during a planning application. In some circumstances, a planning condition will be included on the planning permission requiring the submission of a noise report.

As noise surveys are usually carried out prior to completion of a development, compliance with any noise standards are demonstrated by calculation. However, the local authority may also request a post-completion noise survey to prove that noise standards have been achieved.

Who is suitably qualified to carry out noise assessments and provide a noise report?

A noise survey must be carried out by a suitably qualified acoustic consultant. APT Sound Testing is a UKAS accredited company and as such is deemed suitably qualified to undertake noise surveys for planning, we also have vast amount of experience and skill in dealing with PPG24 Noise Surveys for the planning applications for all types of developments throughout the United Kingdom.

If you would like more information on our PPG24 noise assessments or PPG24 Noise Surveys then please contact us at: or visit our website at:



In our experience its often the location and poor dwelling layouts that can cause sound testing failure. plays an important role in relation to the levels of subsequent ambient or background noise that surrounds the occupants. Loud  noise sources such as Roads with high traffic volumes, railway lines or airports or entertainment venues can provide a high level of ambient background noise, which may help to ‘mask’ the perceived noise that is being transmitted between dwellings.

Planning Room layouts and functions

Planning a good acoustically favorable dwelling layout can help to reduce the number of noise problems that will occur and help you pass Part E Sound Testing

Main ‘habitable’ rooms such as Kitchens or living rooms, which back onto bedrooms of the adjacent dwelling, are more likely to lead to noise complaints. Kitchen cupboards doors may transmit impact noise through to the bedroom next door through the dividing partition; this can lead to annoyance and frustration for the neighbor.

If neighbours have varied working patterns the layout and the use of rooms are particularly important. Complaints about noise may more often result when the living room of one dwelling is over a bedroom of another dwelling, for example.

Changes to the external building façade

APT have undertaken many façade sound tests to ISO 140 Part 5, in our experience many of the new buildings are struggling to achieve a rating of 40dB, which makes a mockery of Part E as you need to achieve 43dB and 45dB for sound testing on refurb and new build dwellings. Often simple upgrades such as the replacement of double to triple glazing can reduce the level of external noise (termed background noise) entering the dwelling. As such, there may be less background noise and neighbours may hear each other more easily.


Neighbour Relationships

Often the perceived quality of sound insulation may also be influenced by the relationship with their neighbor. If the relationship is amicable then the noise intrusion and the level of noise may be more acceptable than in situations where there is disagreement or hostility between neighbours. Noise issues may only become apparent when there is a change in the lifestyle or the neighbor adopts new work patterns, or when new neighbours move in. Even if the building has passed their dwelling sound test with good results, people may pick up noise in the early AM if neighbours are returning from their work shift.

New building works

Previous service works for water pipes, drainage and heating systems can influence the overall performance of a wall or floor, i.e. access may be needed the SVP pipes within the pipe boxing. During the works the acoustic lagging may be removed to get to the SVP pipe; unfortunately this may not be replaced after the works are complete. The subsequent sound of rushing water may then be audible. Also during other works ceilings such as lathe and plaster may have been removed and replaced by one layer of 12mm plasterboard, even though this is a new material, it may not have the mass of a 40mm lathe & plaster ceiling resulting in the increase of noise levels from the property above.

Surface material changes (carpet to timber)

In our experience one of the most common triggers for complaints is the change of room surface (e.g. from carpet to laminate flooring) treatments or materials. We have undertaken many sound tests on existing buildings where the occupier has changed from carpet to timber and/or tile. Without the applying the acoustic upgrades for this change in material this can typically lead to a 20dB reduction in insulation performance. This can lead to occupants below this floor changing their assessment of impact noise from “acceptable” to a level they may describe as “unacceptable”.

Past experience

People who have previously lived in detached houses and move into a flat or attached dwelling they may feel that the level of sound insulation is poor, however this may not be the case and the sound tests results may actually be quite good – well in excess of the minimum standards as set out in Part E of Building Regulations.

If you would like more information in regards to our acoustic and sound testing services, please contact us now at or visit our website at:



We at APT often get asked why a design that has passed easily in the laboratory has struggled – and sometimes failed to pass the sound testing for Part E

Despite site contractor’s best endeavours, it is extremely difficult to build to the stringent exacting standards of the test laboratory. When the construction assembly is undertaken in the lab, it has gone through an exacting installation technique prior to the sound test, which is the reason why better sound testing levels are achieved.

Throughout the acoustic installation the manufacturer’s guidance is followed to the letter by the lab technicians. Although, this should be replicated on site, it seldom is and so a design which can be robust and well in excess of Part E requirements can lose 10dB or more compared to the results achieved in the laboratory. Unfortunately there are many reasons why this occurs and it’s usually down poor quality operatives and other on-site other issues such as cost, time and programming constraints come into play.

We have undertaken many sound tests where the acoustic design details showed the partitions should achieve in excess of 50dB, only for it to fail with sound test results below the required 45dB.  This is why a 7-9dB tolerance should be allowed between the dB rating of the acoustic solution and the onsite construction. Unfortunately, if cost constraints come into play and subsequent allowances aren’t made for the onsite acoustic performance there is a high probability it will fail the sound testing, which may lead to expensive remedial works as well as delayed handover which will be far more expensive in the long run.

sound testing

There are many reasons why the onsite construction results are worse than the laboratory,   issues such as such as using the wrong fixings and not installing the insulation to name but two. Either of these can easily lead to a sound test failure.

It is very important that acoustic installation details are closely followed to ensure that the onsite results are as close as possible to the laboratory target. We offer an acoustic design service, to help you achieve Part E compliance at the first attempt.

The following list explains what should be done to achieve a successful sound tests and Part E compliance:

  1. Ensure that the construction team is fully briefed of the acoustic details.
  2. Ensure that the manufactures installation booklet is on site at all times.
  3. Ensure that the Acoustic floor is fitted with staggered joints.
  4. If you are installing floating screed ensure all isolation layer joints are overlapped and taped.
  5. Ensure all the Acoustic floor is sealed watertight even around heating pipes.
  6. Do not nail or screw through an Acoustic Floor.
  7. Do not screws plaster board into joists, when using a Resilient Bar system.
  8. Ensure the insulation fills the whole width of void
  9. Pack around pipe work and double board with staggered joints.
  10. Ensure that the plasterboard on any walls is complete right down to within 5-10mm of the subfloor and seal all gaps.
  11. Ensure you use the isolation tape around the wall of each room.
  12. Ensure plasterboard is fitted with staggered layers and all joints sealed.
  13. If using Resilient Bars ensure that they are fitted as per manufacturer’s recommendations.
  14. Ensure all Fireplaces are blocked up with brick or a twin lined plasterboard system and filled with acoustic insulation.
  15. Ensure that any RSJ’s or supporting steel work is insulated and isolated from plasterboard.
  16. Ensure all waste pipe service runs are boxed in with insulation and plasterboard.
  17. Ensure all doors and windows are installed before the test is carried out, to stop noise transference.

APT offer an acoustic design service to make sure the acoustic elements are being installed as per the manufacturer’s guidelines, if you are worried about passing your sound testing at the first attempt please don’t hesitate to contact us now at: or visit our website at:


Quantifying Sound levels for Sound Testing Failures

Quantifying Sound levels for Sound Testing Failures

APT Sound Testing often ask us about the parameters behind the sound testing under Part E. To try and clarify sound levels in more detail we have written a brief explanation.

What is sound or Noise?

Noise or sound  is often defined as unwanted sound. Sound is defined as any pressure variation heard by the human ear. The sound pressure level (SPL) is a measure of the air vibrations that make up sound. Because the human ear is sensitive to a wide range of pressure levels, the SPL is measured on a logarithmic scale with units of decibels (dB).


How do we  perceive noise or sound?

Healthy human ears perceive pressure variations over a wide range of frequencies — from low as low as 20 Hz to frequencies as high as 20,000 Hz. The human ear’s range starts at the threshold of hearing (0 dB) and ends at the threshold of pain (around 140dB) which would be the same as standing next to a large jet engine.

The human ear is less sensitive to sounds in the low frequencies compared to the higher frequencies. For example, a 50 Hz tone must be at a level of 85 dB in order to be perceived by the human ear as being the same loudness as the higher frequency 1000-Hz tone at a level of 70dB

How do you quantify sound?

As mentioned above, sound levels are usually measured and expressed in decibels (dB). Most environmental noise does not consist of a single frequency, but rather a broad band of frequencies differing in sound level. The intensities of each frequency add to generate sound. The method commonly used to quantify environmental sounds involves evaluating all of the frequencies of a sound according to a weighting system which reflects that human hearing is less sensitive at low frequencies and extremely high frequencies than at the mid-range frequencies. This is called “A” weighting, and the decibel level measured is called the A-weighted sound level (dBA).

Quantifying sound testing failures

As a rule of thumb, a doubling in the loudness of the sound occurs with every increase of 10 dB in sound pressure. In other words, for most individuals a 60 dBA noise would sound twice as loud as a 50 dBA noise.

If a sound testing fails, the client often asks by how much. When we confirm it has failed by 5dB they usually say ‘if that’s the case I only need to improve the partition by 10%’, unfortunately that isn’t the case – the partition has actually failed by 50% subsequently the partition will need major upgrades to pass the sound testing under Part E of Building Regulations.

APT Sound Testing can advise on all types of acoustic design, whether it’s accomplished during initial construction or during a refurbishment/renovation project.  We have the technical experience to help identify and rectify your soundproofing or noise control problem.

If you would like more information in regards to sound testing please follow our blog at: or contact us at: or visit our website at:



We are often asked what types of sound test and noise surveys we can undertake. We offer all types of Sound Testing and noise surveys as well as design consultancy. Here is a quick summary of our acoustic services:

We are accredited to carry out Sound Insulation testing for:

  • Houses and flats in compliance with Part E of the Building Regulations.
  • Houses & Flats in compliance with the Code for Sustainable Homes.
  • All commercial buildings in compliance with BREEAM.
  • Classrooms within schools in compliance with BB93.

sound testing

We also try to provide a ‘one stop’ testing service for compliance with the latest Building Regulations. Our full ranges of services are:

Air Tightness Testing

  • Pre-completion Air Tightness Testing for residential and commercial buildings (Part L1&L2)
  • Air Tightness Design Reviews.
  • Combined Pre-completion Air & Sound Test (Part L1 & E) improves coordination and saves cost!

Sound Insulation Testing

  • Pre-completion Sound Testing for residential and school buildings (Part E & BB93)
  • Acoustic Design Consultancy (Part E & BB93)

Noise Surveys

  • Noise Surveys for planning (PPG24)
  • Noise Surveys for proposed air conditioning and other noise sources (BS4142)

Thermal Surveys

  • BREEAM Thermal surveys to show continuation of Insulation (Part L)
  • To locate leaks within roofs/walls and under floor heating. (Fault Diagnosis)
  • Annual Infrared Surveys on Electrical Switchboards and plant (Annual Maintenance)

Energy performance Certifications

  • Design Stage SAP & SBEM Certification (Part L)
  • As Built SAP & SBEM Certification (Part L)
  • Energy Performance Certificates (Part L)

Ventilation Testing

  • Ventilation Testing – now mandatory on all domestic ventilation systems (Part F)

Integrity Testing On Server Rooms

  • Integrity Testing on Server Rooms (rooms that have gaseous fire suppressant systems) – These must be carried out annually (ISO 15004)

UAV Aerial Surveys (unmanned)

  • Roof condition surveys on Residential, Factory and Church Roofs.
  • Thermal Surveys of Large Roofs.
  • Progress photos of large construction sites; i.e. at greenfield, foundations, envelope & completion stage.
  • Photos of completed dwellings and buildings for advertising purposes.
  • The Creation of 3D models of your project/site.

If you would like more information in regards to our sound insulation testing and/or air tightness testing packages, please don’t hesitate to contact us at: or call Darren direct on 07775623464



One of the most common reasons for partitions failing the sound testing is down to noise flanking between partitions.

Noise Flanking is a term used by acoustic engineers wherein the sound passes over the top or under the primary partition separating the two spaces under test. Flanking sound transmission can be especially bothersome in multi-family residential buildings do to the sheer number of dividing partitions.

One way to reduce the chance of to flanking transmission/s is at the design phase of the dwelling. Unfortunately, by Simply specifying high performance wall and floor partitions between dwelling is no guarantee to a sound isolation and subsequently a successful sound test. APT Sound Testing offer both preconstruction and post construction design solutions to achieve the required sound isolation requirements of Part E of Building Regulations.

This Plate Shows The Main Air Leakage Paths


We also offer an acoustic onsite inspection service to ensure that the sound insulation elements are being installed as per manufactures guild lines and the quality of the workmanship is consistent with ‘best practice’ noise control procedures.

You can also undertake you own checks by asking the design consultant i.e. the architect or the builder what steps have been taken to insure your building will be sound adequately sound proofed from your neighbours and from noise intrusion through perimeter envelope from outside the building, after all there isn’t any point your dwelling having high spec acoustic insulation between the inner partitions if sound is transferring through the outer envelope.

 It is never safe to assume because the architect has specified high performance walls, windows and floor/ceiling assemblies that the materials and onsite workmanship will result in compliance with the anticipated results and ultimately a successful sound test. In all these instances successful sound isolation in your home depends on the workmanship during the sound insulation installation phase, the problem is the site installer may know little about noise control techniques unless he is give the right supervision and direction the construction phase.

Part E of Building Regulations stipulates the minimum standards for noise control between residential dwelling units. Upon completion of the building the Building inspection department will need the sound test certification prior to the issue a certificate of occupancy. This shows that the building meets minimum building code standards including sound isolation.

Typical Flanking Sound Transmission Pathways:

  • Dividing Floors – Through Floor and Floor Joist Space (if insulation has not been installed or direct fixing to joists without a drop ceiling below the partition under test)
  • Dividing Ceilings – Above and Through the Ceiling Space (where an adequate acoustic break has not been carried on through the ceiling void)
  • Through Structural Steel (structural steel beams are often a major cause of noise transmission as plasterboard is often fixed directly to the steel without sound breaks)
  • Shared Structural Building Components – Floor Boards, Floor Joists, Continuous Drywall Partitions, Continuous Concrete Floors, and Cement Block Walls.
  • Through Windows (if they are no double glazed or have secondary glazing as a minimum)
  • Fixtures & Outlets – Light Switches, Telephone Outlets, and Recessed Lighting Fixtures (if penetrations have been cut back to back with the opposite dwelling under test)
  • Structural Joints – Perimeter Joints at Wall & Floor, Through Wall & Ceiling Junctures (these should be filled with acoustic mastic)
  • Plumbing Chases – Junctures Between the Walls & Floor Slab Above or at the Exterior Wall Juncture (this should be filed with mortar etc. to add mass to this weakened area)
  • Around the End of the Partition Through the Adjacent Wall (acoustic mastic should be used to seal this junction)

Even if you your wall/floor has been designed so it should provide a high acoustic rating exceeding Part E requirements, this may not be enough. Unfortunately, sound will always find the weakest link, for instance construction workers will usually jack the plasterboard tight to the ceiling in order to achieve a nice tight joint at the ceiling. This often leaves a void or potential noise transference point at the floor/wall junction, which will eventually be covered with a piece of thin skirting board. Failure to fill the joint between the wall and the floor with acoustic mastic can reduce even a 50dB rated wall to under 40dB which will fail the minimum standard of 45dB for sound insulation testing as stipulated within the Building Regulations Part E.

This Video Clearly Shows Sound Flanking Through a Wall

Often the sound insulation manufacture will provide test lab results for their material. However, you should usually reduce the acoustic target by 4-5dB due to onsite construction. When the construction assembly is tested in the lab it is also certified and the installation techniques are described in detail.  Unfortunately it is not always possible to replicate the exact conditions on the site compared to the ideal conditions within in a lab setting, which is a far more controlled and scrutinised environment. This is the reason why a 5 point difference is allowed between the construction design on paper and the actual on site performance.

APT Sound Testing can advise on all types of acoustic design, whether it’s accomplished during initial construction or during a refurbishment/renovation project.  We have the technical experience to help identify and rectify your soundproofing or noise control problem.

If you would like more information in regards to sound testing please follow our blog at: or contact us at: or visit our website at:



The first stage of the any project is to undertake robust acoustic design for successful sound testing.  To start this process you need to send  through the design drawings for review, including elevations & sections etc. APT can then review the design detailing to check that the construction details proposed are capable of passing the sound tests. This usually takes place straight after planning has been approved as increased cost savings can be realised at the earliest stage.


APT Sound Testing will evaluate the construction methods and materials specified to ensure that they are capable of meeting the acoustic requirements of Approved document E and subsequently pass the sound testing. The typical areas we check are:

  • The wall and floor design are acoustically robust, to comply with Building Regulations Part E.
  • Check there are no potential flanking points, where isolated partitions are wrongly mechanically fixed together to caused noise bridging.
  • The acoustic treatments for Soil Pipes, Stair Cases Steel Beams etc. to ensure they are acoustically fit for purpose, as these are some of the many areas that get missed that can lead to sound test failure.
  • The Lighting specification to, ensure they are acoustically complaint to the overall design i.e. down lighter design etc.
  • Acoustic floor treatments are compatible with the proposed floor finishes i.e. Carpets, Laminates, Floor Tiles and under floor heating systems.

 If you would like more information in regards to acoustic design and/or sound testing please follow our blog at:, or contact us at: or visit our website at: