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Confirm your new build or conversion meets the sound insulation requirements of Approved Document E - With 17 years of building-compliance experience, Energy Report provides practical Part E sound insulation testing for developers, architects, contractors and building owners across the South of England and the South West. We help you plan pre-completion testing at the right stage, understand what will be assessed and receive clear, project-focused guidance throughout the process.
What is Part E sound insulation testing?
Part E sound insulation testing also known as acoustic testing, sound testing or pre-completion sound testing checks how well separating walls and floors resist the passage of sound between adjoining dwellings or relevant residential spaces. It is used to demonstrate compliance with Approved Document E: Resistance to the passage of sound, which provides statutory guidance for building work in England.
The tests are carried out on site during construction, before completion. They assess two distinct types of sound transmission:
| Test type | What it assesses | Typical separating element |
| Airborne sound insulation testing | How well a wall or floor resists airborne sound, such as speech, television or music. | Separating walls and floors between dwellings or relevant rooms. |
| Impact sound insulation testing | How well a separating floor limits impact noise, such as footsteps or moving objects. | Separating floors and stairs with a separating function. |
In simple terms: Part E testing provides evidence that the relevant walls and floors have been built to provide reasonable resistance to sound between homes or other relevant spaces.
Approved Document E covers sound insulation requirements for dwelling-houses, flats, rooms for residential use and schools. The requirements and testing approach can vary according to whether the scheme is purpose-built, formed through a material change of use, or contains rooms for residential purposes. We will help you establish the relevant scope for your project.
Why do I need a Part E sound test?
Where pre-completion testing applies, it is a key part of demonstrating compliance with Requirement E1 of the Building Regulations. Requirement E1 concerns resistance to sound from other parts of the same building and adjoining buildings. A successful test report provides building control with evidence of the measured acoustic performance of the relevant separating elements.
For project teams, Part E sound testing is about more than a final compliance step. It provides a useful check on whether details have been constructed as intended, including the interfaces and junctions that can affect acoustic performance. Planning the test early can help you manage access, programme the right plots and address any concerns before handover is at risk.
Part E testing can help you to:
- Demonstrate Building Regulations compliance where pre-completion testing is required.
- Plan construction and completion activity around a clearly understood test programme.
- Identify potential acoustic issues early while there is still time to investigate and take appropriate action.
- Provide clear evidence to building control through a formal sound insulation test report.
- Protect the quality of the completed homes by checking the performance of separating walls and floors in the finished building.
Need advice before you book? Talk to our team early in the programme. We can help you understand the likely test scope and the information needed for a smooth visit.
Part E testing requirements at a glance
Approved Document E sets different performance values depending on the building type and whether it is purpose-built or formed by a material change of use. The table below summarises the values in Approved Document E Table 0.1 for the most common residential scenarios.
| Building type | Separating element | Airborne sound insulation, DnT,w + Ctr | Impact sound insulation, L’nT,w |
| Purpose-built dwelling-houses and flats | Separating wall | Minimum 45 dB | Not applicable |
| Purpose-built dwelling-houses and flats | Separating floor or stair with a separating function | Minimum 45 dB | Maximum 62 dB |
| Dwelling-houses and flats formed by material change of use | Separating wall | Minimum 43 dB | Not applicable |
| Dwelling-houses and flats formed by material change of use | Separating floor or stair with a separating function | Minimum 43 dB | Maximum 64 dB |
The correct test programme and performance criteria must always be confirmed for the particular development. Purpose-built rooms for residential purposes, including some forms of student accommodation or residential accommodation, may have their own relevant criteria. Historic buildings and unusual projects should be discussed with building control and an appropriate specialist at an early stage
Our Part E sound insulation testing process
1. Plan your test early
Sound insulation testing is normally carried out on site as part of the construction process. We recommend discussing the anticipated completion programme early, particularly on developments with repeated dwelling types or several groups of construction. This gives you time to identify the likely testing locations, coordinate access and make sure the relevant areas are ready when the test takes place.
2. Confirm the project scope
We will ask for the information needed to understand your scheme, including the project address, building type, plot numbers, construction type, relevant separating walls and floors, expected completion dates and building-control details. This helps us recommend an appropriate test plan and provide a clear quotation.
3. Prepare the property for testing
A Part E test should be carried out when the relevant rooms and separating elements are complete and accessible. Before the visit, it is important that construction details are in place, rooms can be accessed safely and the test areas are free from disruptive work and excessive background noise. We will provide practical pre-test guidance based on the project.
4. Carry out airborne and impact sound tests
For airborne tests, a controlled sound source is used in one room while measurements are taken in the adjoining receiving room. For impact tests, a standard tapping machine is used on the floor while the sound level is measured in the room below. The specific tests depend on the separating elements being assessed and the agreed test programme.
5. Receive clear results and next steps
Your report will set out the test results for the sampled separating elements and the relevant measured performance values. Where results need further attention, we will explain the findings in clear language so the project team can investigate the likely cause and agree appropriate next steps with building control.
How many Part E sound tests are needed?
The number of tests depends on the property type, the relevant separating walls and floors, the number of construction groups or subgroups, and the test programme agreed with building control. Approved Document E describes the following normal sets of tests:
| Development scenario | Normal set of tests | Practical note |
| Dwelling-houses, including bungalows | 2 airborne tests across a separating wall. | The normal set tests pairs of rooms on opposite sides of the separating wall. |
| Flats with separating floors but no separating walls | 4 tests: 2 airborne and 2 impact tests. | The tests are carried out across the separating floor. |
| Flats with both a separating floor and wall | 6 tests: 4 airborne and 2 impact tests. | A full set normally requires access to at least three flats. |
Under the normal programme, building control will ask for a set of tests between the first dwellings, flats or rooms for residential purposes due for completion or sale in each group or subgroup. If tests are satisfactory, at least one set of tests is normally stipulated for every ten relevant units in a group or subgroup. Testing may be more frequent earlier in a run of completions, so potential issues can be addressed promptly.
Every development is different. Contact us with your drawings, unit schedule and anticipated completion dates, and we will help you plan the testing requirements for your site.
When should sound insulation testing be booked?
Book Part E testing as soon as you have a reliable construction programme. The test itself needs the relevant separating walls, floors and rooms to be complete, accessible and ready for measurement, but the planning should happen much earlier.
Early booking is particularly helpful for apartment schemes, phased developments and conversions, where the sequence of completion, available access and the number of relevant test locations can affect the programme. By involving us before final finishing works and handover pressures build, you give your team more time to check readiness and respond if any acoustic issues are identified.
What can affect a Part E sound test result?
Sound insulation is not determined by one material alone. The finished performance can be affected by the entire separating construction and how it has been built. Typical considerations include:
- The separating wall or floor build-up, including mass, linings, cavities and resilient layers.
- Flanking transmission, where sound travels around rather than directly through the separating element.
- Junction details, including connections to external walls, internal walls, floors, ceilings and roofs.
- Penetrations and service routes, especially where they introduce gaps or rigid connections.
- Workmanship and sequencing, including incomplete seals, misplaced insulation and unintended acoustic bridges.
- Floor finishes and ceiling treatments, which can influence impact and airborne sound performance in relevant floor constructions.
Approved Document E includes detailed examples of separating constructions and junction considerations, but there are alternative ways to demonstrate compliance. The right approach should be considered as part of the design and construction strategy, not left until the test date.
New-build homes, conversions and Robust Details
New-build houses and flats
Pre-completion sound insulation testing is commonly used to demonstrate Part E compliance for new houses and flats. The test programme should be discussed with building control and planned around the construction sequence. The relevant performance values for purpose-built homes are shown in the table above.
Conversions and material change of use
Part E testing is also relevant where houses, flats or rooms for residential purposes are formed through a material change of use, such as certain office-to-residential or commercial-to-residential conversions. The performance values differ from those for purpose-built homes, and existing structures can present particular design and construction considerations. Early acoustic advice is especially valuable on these projects.
Robust Details
For qualifying new-build houses and buildings containing flats, approved and correctly registered Robust Details can provide an alternative route to pre-completion sound insulation testing for the relevant elements. This route is subject to the required conditions, including notification to building control and construction in accordance with the specified detail. If you are considering Robust Details, confirm the approach with your design team, building control and the relevant Robust Details requirements early in the project.
Preparing for a Part E sound insulation test
A well-prepared test visit helps protect your programme. Before the test, you should normally ensure that:
- The rooms selected for testing are complete enough for the agreed test procedure and are safely accessible.
- The relevant separating walls, floors, ceilings and associated construction are complete.
- Access has been arranged to both sides of the separating wall or to the rooms above and below a separating floor.
- Noisy works, plant or other activities that could affect the measurements are scheduled away from the testing period.
- The test areas are clear enough for equipment to be positioned and doors can be operated as needed.
- The site team understands which plots or rooms are being tested and when access is required.
We will confirm the final readiness requirements when the visit is booked. If you are unsure whether a plot is ready, contact us before the test date so that we can help you avoid an abortive visit.
What happens if a Part E sound test fails?
A failed test means that one or more individual measurements did not demonstrate the relevant performance value. The next step is to investigate the likely cause with the project team. Depending on the construction and results, this may involve reviewing the separating element, flanking paths, service penetrations, junctions, floor or ceiling build-up, or site workmanship.
Approved Document E states that appropriate remedial treatment should be applied to the rooms that fail, and building control may require further evidence that other affected rooms achieve the necessary standard. Additional testing may then be needed to demonstrate the effectiveness of the remedial work.
Energy Report will explain the test findings clearly and help you understand the next steps. We do not promise a pass before the building has been assessed, but we do provide practical, responsive support to help you manage the process effectively.
FAQs
What is a Part E sound insulation test?
A Part E sound insulation test is an on-site pre-completion test used to assess how well relevant separating walls and floors resist the passage of sound. It is carried out to help demonstrate compliance with Approved Document E of the Building Regulations in England, where the requirements apply.
Is Part E testing the same as acoustic testing or sound testing?
Yes. Part E sound insulation testing is often described as acoustic testing, sound testing, sound proof testing or pre-completion sound testing. In a Building Regulations context, it normally refers to measuring airborne sound insulation and, where relevant, impact sound insulation across separating elements.
When is Part E sound testing required?
Part E testing may be required for relevant new-build dwelling-houses, flats, rooms for residential purposes and certain material-change-of-use projects in England. The testing requirement, number of tests and selection of test locations should be agreed with building control for the development. Qualifying Robust Details may provide an alternative route for relevant elements in certain new-build houses and flats.
Does Part E apply to detached houses?
Part E Requirement E1 focuses on sound transmission from other parts of the same building and adjoining buildings. A detached house without relevant separating elements will not usually need pre-completion sound insulation testing under E1. However, every project should be checked against its specific Building Regulations scope and building-control requirements.
What is the Part E standard for new-build houses and flats?
For purpose-built dwelling-houses and flats, Approved Document E Table 0.1 states a minimum airborne sound insulation value of 45 dB for separating walls and separating floors or stairs with a separating function. For separating floors or stairs, the impact sound insulation value must not exceed 62 dB. The relevant criteria must be confirmed for the specific development.
What is the Part E standard for conversions?
For dwelling-houses and flats formed by a material change of use, Approved Document E Table 0.1 states a minimum airborne sound insulation value of 43 dB for separating walls and separating floors or stairs with a separating function. For separating floors or stairs, the impact sound insulation value must not exceed 64 dB. Historic buildings and unusual cases may require early discussion with building control.
What is the difference between airborne and impact sound testing?
Airborne sound testing measures how well a wall or floor reduces sounds transmitted through the air, such as speech, music or television. Impact sound testing measures how well a separating floor limits noise caused by impacts, such as footsteps. Impact testing is generally relevant to separating floors and stairs, not separating walls.
How many Part E tests are required on a development?
The number of Part E tests depends on the property type, construction groupings, relevant separating elements and the programme set by building control. A normal set can comprise two, four or six individual tests, depending on the development type. Assuming tests are satisfactory, Approved Document E says building control should normally stipulate at least one set for every ten relevant units in a group or subgroup.
When should I book a Part E sound test?
Book the testing as soon as your completion programme becomes clear. The selected rooms must be ready and accessible at the time of testing, but early planning helps you coordinate plots, access and site activity, particularly for flats, phased schemes and conversions.
How long does a Part E sound insulation test take?
The duration depends on the number and type of tests, property layout, access arrangements, background noise and site readiness. We will give you a project-specific indication when we understand the building type, test scope and number of units.
What do I need to do before the sound test?
Ensure the agreed rooms are complete enough for testing, safely accessible and free from disruptive activity. You will need access to both rooms on either side of a separating wall, or to rooms above and below a separating floor. We will provide specific readiness guidance before the appointment.
Can you carry out Part E testing for flats and apartment blocks?
Yes. Part E sound insulation testing is commonly needed for new-build flats and apartment blocks. These projects need careful planning because the test set may include both separating walls and floors, and access to multiple flats may be required for a full set of tests.
Can you carry out Part E testing for conversions?
Yes. We can support relevant residential conversion and material-change-of-use projects. Because existing structures can present different acoustic challenges, it is sensible to discuss the proposed construction and test planning early in the project.
What report do I receive after Part E testing?
You receive a sound insulation test report that records the project and test information, rooms tested and measured results. The report is prepared to support the Building Regulations compliance process and can be provided to the relevant project team and building control as required.
What happens if the sound test does not achieve the required result?
We will explain the measured result and help the project team understand the next steps. Appropriate investigation and remedial work may be required, followed by further testing where needed. Building control will determine what evidence is required to demonstrate compliance for the development.
Do Robust Details mean I do not need Part E testing?
Qualifying Robust Details can provide an alternative to pre-completion testing for relevant elements in certain new-build houses and flats. This only applies where the detail is approved and correctly registered, the required notification is made and the work complies with the specified detail. Confirm the route with building control and the project team before relying on it.
Does Part E apply outside England?
This page is written for building work in England. Building Regulations and acoustic requirements differ across the UK, so please contact us with your project location and details for the appropriate advice.
Why work with Energy Report?
- Practical pre-test guidance: We help you understand the likely test scope and site-readiness requirements before the visit.
- A responsive, project-focused service: We work around your construction programme wherever possible and communicate clearly with the wider team.
- Clear, useful reporting: We present measured results in a straightforward report to support the compliance process.
- Joined-up compliance support: Our wider building-compliance knowledge can help you coordinate Part E testing with related design and completion requirements.
- Approachable technical experience: With 17 years in building compliance, we bring practical understanding and clear advice to every project.
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