Acoustic Consultants

Building Regulations: Sound Insulation Testing From ACA Acoustics

At ACA Acoustics, we offer competitive sound insulation testing for new or conversion houses and flats to ensure compliance with Approved Document E of the Building Regulations.

Sound insulation tests are required on most new-build houses or flats, or any dwellings formed by material change of use – the formal term for conversion developments.

Our consultants are highly experienced. Your project will be dealt with by an expert in sound insulation and your sound tests will be conducted by a fully qualified acoustic consultant.

ACA Acoustics Insultation Discount CTA


Acoustic Design and Sound Insulation Testing

Designing separating walls and floors and the associated junction details so that your development will meet the strict performance standards of Approved Document E requires specialist knowledge and experience. This is particularly the case for developments formed by material change of use (conversions), where you are constrained by the structure of the existing building.

At ACA Acoustics, we offer an end-to-end design and sound insulation testing service for property developers to ensure new-builds and conversions meet the requirements of Building Regulations on completion.

Our service includes:

  • We provide a FREE initial acoustic design review service of your proposed separating walls and floors between dwellings.
  • If needed, more detailed acoustic design and acoustic modelling of the building can be carried out.
  • For some developments it might be beneficial to carry out preliminary sound insulation tests on existing separating walls/floors in conversion developments. This confirms if the current structure will achieve the performance standards (saving money on unnecessary additional work) or the level of improvement required.
  • Site inspections from our experienced consultants during the construction phase.
  • Pre-completion sound insulation testing. ACA Acoustics are fully SITMA accredited to undertake sound insulation tests, meaning our tests will be accepted by your Building Control Officer.

We strongly recommend that you discuss your project with an acoustic consultant specialising in sound insulation at an early stage. This is the best way to make sure that your development will pass Building Regulations sound testing the first time.

Please call us on the numbers above, or fill in the contact form and we’ll be in touch to discuss your project.


What Is Required By Building Regulations Approved Document E?

Building Regulations Approved Document E for Sound Insulation Testing
Approved Document E (Resistance to the Passage of Sound) of the Building Regulations establishes the soundproofing standards for separating walls and floors between new or conversion dwellings and between dwellings. It also requires acoustic insulation internally to protect habitable rooms from excessive noise from other areas of the dwelling.

There are four sections to Approved Document E:

  • E1: Effective prevention of sound transmission to dwellings from adjoining buildings, including apartments and terraced or semi-detached houses.
  • E2: Sound transmission within the home.
  • E3: Reverberation – the amount of ‘echo’ – in communal areas of apartment blocks.
  • E4: Acoustic conditions in schools.


How Many Sound Tests Will I Need? 

A common misconception is that sound tests should be carried out on 10% of properties in a development. Unfortunately, it’s not quite as simple as that.

The number of tests required depends on the type of properties, the number of dwellings, and if you have different construction separating walls or floors between dwellings. Approved Document E requires that development is split into separate groups for houses (including bungalows), flats, and rooms for residential purposes. These can include hotels, hostels, halls of residence, or a residential home, but does not include rooms in a hospital used for patient accommodation. Different groups are required for developments which include both new and conversion properties. The groups are then split into sub-groups if required. For example, if there are different constructions separating walls or floors between dwellings.

One set of tests is carried out for every ten properties within each group or sub-group. 

  • A set of tests for houses comprises two airborne sound insulation tests on separating walls between habitable rooms.
  • A set of tests for flats with just separating floors comprises two airborne sound insulation tests and two impact sound insulation tests between habitable rooms.
  • A set of tests for flats with separating walls and floors comprises two airborne sound insulation tests on separating walls, and two airborne sound insulation tests and two impact sound insulation tests on separating floors between habitable rooms.

Tests are not conducted on hallways, stairwells, or corridors.

It can be confusing working out how many sets of tests are required, or which individual plots/rooms need to be tested.  Luckily, ACA Acoustics are the experts and can work this out for you.


The Different Types Of Sound Insulation

When assessing sound transmission between properties there are two elements to consider, airborne sound and impact sound:

Airborne Sound Insulation

Airborne sound transmission relates to noise from televisions, music, and speech. 

For separating walls and floors between properties, the minimum airborne sound resistance is DnT,w + C’tr ≥45dB in new builds and DnT,w + C’tr ≥43dB in houses or flats formed by material change of use (the formal term for conversions used in the Building Regulations). 

To comply with Requirement E2, walls between bedrooms and other rooms within a dwelling (excluding walls with doors or partitions with en-suite bedrooms), and internal floors within a house or maisonette must be designed to achieve a performance of Rw ≥40dB.

Impact Sound Insulation 

For impact sounds – footsteps or dropped objects, for example – the threshold for transmission is L’nT,w ≤62dB for floors and stairs in new-build properties and L’nT,w ≤64dB in conversions.


What Do The Different Performance Standards Mean?

DnT,w is a measure of the “standardised level difference”, tested on site.  The reduction in sound from a room on one side of the wall or floor to an adjoining room is measured and the result corrected for the level of ‘echo’ in the receiving room.  This means that, in theory, the measured DnT,w performance should be the same whether the rooms are empty and unfurnished or have carpets, curtains, and soft furnishings.

The C’tr correction penalises structures which provide poor sound insulation at low frequency.  Low frequency noise, such as music ‘bass’, is often more disturbing than other sounds.

A DnT,w + C’tr of 45dB in new build properties and DnT,w + C’tr 43dB in properties formed by material change of use is the minimum performance to provide a reasonable standard for future occupants.

Where there is a non-residential property adjoining a dwelling then higher standards of sound insulation may be required. Approved Document E advises that in this situation specialist advice is needed to determine the appropriate level. Contact ACA Acoustics if this is applicable and our experienced consultants can advise you accordingly.

The performance standard for internal walls/floors within a dwelling is given as Rw 40dB.  It is important not to confuse Rw and DnT,w values. DnT,w is tested on site, but an Rw is tested in a laboratory.  The Rw of a separating wall/floor is always higher than the corresponding DnT,w.  This is very important to remember when designing separating walls and floors.

The L’nT,w value is specific to impact sound transmission. For airborne sound transmission the higher the value the better the performance but for impact transmission the lower the value the better.


Is Approved Document E Applicable For Detached Properties?

As they do not have any separating walls or floors, detached houses are not required to comply with the strict acoustic standards laid out in Approved Document E, although internal walls and floors do need to comply with Requirement E2 of ADE.


Other Sound Insulation Test Requirements

We also carry out sound insulation testing for other reasons, such as to comply with BREAAM HEA 05, to reduce noise pollution from commercial properties, or investigate complaints about sound transmission.

For more information or to arrange sound insulation testing for your project, please fill in the contact form or call us today.

Get In Touch



"I want to share with you my appreciation for the honesty and sincerity you have shown throughout our work together.

It’s getting rarer these days that clients’ interests are put ahead of pressure to generate fees.

I would definitely recommend you to others."

Philip Catterall

"I have had the pleasure of using ACA Acoustics’ services on a high-end residential project in Vauxhall, London.

The commitment and proactiveness received from Rob Cant and his team was greatly appreciated on an extremely challenging and short time-framed project. This resulted in ACA Acoustics providing acoustic consultancy services on the current 51-storey commercial fit out project in Central London.

I would not hesitate with recommending their services as they are my preferred company for acoustic consultancy."

Joe Wu – T Clarke PLC

"I have been using ACA Acoustics during my employment at different companies since Rob set the business up in 2012. Rob and his team offer an excellent service and very competitive costs for carrying out acoustic sound surveys and reports. In the fast pace nature of the hospitality client field their fast turnaround is greatly valued and helps me to build a robust offering to my clients."

Craig Ballantyne – Spiritus Technical Services Limited

"We used Rob from ACA Acoustics and would highly recommend their services. The work was carried out to an extremely high standard, these guys obviously know their business.

There was some opposition to our project and those opposing employed an independent acoustic agent to try and discredit the report Rob had produced. However, the other report was thrown out and deemed totally inadequate and the Local Authority praised the report submitted by ACA Acoustics.

As I say, these guys know their stuff and are extremely competent and most professional."

Sanchia Ascroft – The Thatch Barn, Yelling

"ACA Acoustics’ practical understanding of the HVAC industry and professional yet common sense approach to finding the right solution for each project is the reason why I’d always choose to use them on my projects and recommend them to my clients."

Ed Fellerman – Chapman Ventilation Limited

"I’ve worked with Rob and ACA for a number of years on numerous projects, and their proactive approach and negotiation skills have helped my clients and I overcome various difficult challenging noise issues to secure tricky planning consents.

As a planning consultancy we have worked with various noise consultants and I have found ACA to be the most pragmatic and adept, going beyond simply undertaking noise calculations to help find solutions and fight our corner when needed."

Mark Shearman – Firstplan

"I use ACA Acoustics to assist with all our projects which require an acoustic assessment. They also provide the acoustic design for separating walls and floors to comply with The Building Regulations Approved Document E.

Their straightforward and practical advice complements the service I can offer to my clients and I highly recommend their service."

Ian Hubbarde – Link Architecture