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Air Source Heat Pumps
Air Source Heat Pumps: Noise & Planning

Air Source Heat Pumps: Noise & Planning

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Air Source Heat Pumps: Noise, Planning & How to Reduce It

In areas with moderate climates, heat pumps can provide a more environmentally friendly alternative to traditional heating and cooling systems such as gas boilers and conventional air conditioning.

An air source heat pump extracts heat from the outside air and transfers it into your home. You can use the heat generated for radiators, hot water, underfloor heating, and warm air systems.

Many air source heat pumps can also provide cooling during the summer months, making them a versatile solution for year-round temperature control. However, depending on the location and installation, you may need a heat pump noise survey to meet local planning or environmental noise requirements.

Are air source heat pumps environmentally friendly?

Air source heat pumps are generally considered a lower-carbon alternative to conventional fossil-fuel heating systems. Rather than generating heat by burning gas or another fuel, they extract naturally occurring heat from the air.

The system does, however, require electricity to operate. The environmental impact therefore depends partly on the electricity used to power the heat pump, as well as the system’s efficiency.

For homeowners looking to install an air source heat pump, environmental performance is only one consideration. Noise is another important factor, particularly where the outdoor unit is located close to neighbouring properties.

How much noise do air source heat pumps produce?

While air source heat pumps offer significant energy and environmental benefits, noise can still matter.

Depending on the model, operating conditions and installation, an air source heat pump can produce noise levels of up to around 60 dB(A). The actual noise experienced by nearby occupants will depend on factors such as the distance from the unit, surrounding buildings, background noise and how the equipment has been installed.

Where noise from equipment could affect neighbouring properties, an assessment may be required to determine whether the predicted or measured noise is likely to cause a disturbance.

For industrial or commercial noise sources affecting residential areas, noise is commonly assessed using British Standard BS 4142. The standard considers the difference between the noise’s rating level and the background sound level.

As a general indication, a difference of around +5 dB may be considered marginally significant, while a difference of around +10 dB can indicate a greater likelihood of adverse response. Site context and noise characteristics are also important when interpreting the results.

Why do air source heat pumps make noise?

An air source heat pump contains several mechanical and electrical components that can generate sound during operation.

The main components include:

  • Compressor
  • Condenser
  • Expansion valve
  • Evaporator
  • Fan

Although several components contribute to the overall sound output, the compressor and fan are often the most noticeable noise sources.

What does an air source heat pump sound like?

Air source heat pumps can produce a range of sounds during normal operation. These can include:

  • A constant low-level hum from the motor and compressor
  • Fan noise as air moves through the system
  • Vibrations from mechanical components
  • Airflow noise through the heat exchanger
  • Buzzing from electrical or mechanical components
  • Additional sounds during defrost cycles

The character and intensity of the noise can vary depending on the operating conditions. For example, changes in pressure and airflow can affect the sound produced by the heat exchanger and fan.

Frost can also accumulate on the heat exchanger in cold conditions. During defrost cycles, the system may produce different sounds from those heard during normal operation.

For nearby residents, a continuous low-frequency hum can sometimes be more noticeable than a higher-level but intermittent sound. This is one reason assessing the noise characteristics, rather than simply the overall decibel level, matters.

How can air source heat pump noise be reduced?

If you are planning to install an air source heat pump, considering noise at the design stage can help prevent potential problems later.

An acoustic assessment can identify the likely impact of the proposed installation and help determine whether additional noise-control measures are required.

At APT Sound Testing, our air source heat pump acoustic package can include a noise assessment carried out in accordance with the relevant requirements of BS 4142, where applicable.

Where noise levels need to be reduced, acoustic recommendations may include measures such as:

  • Optimising the position of the heat pump
  • Increasing the separation distance from neighbouring properties
  • Using suitable acoustic barriers or enclosures
  • Installing absorptive acoustic panels
  • Addressing vibration transmission
  • Reviewing the specification and operating characteristics of the equipment

The most appropriate solution depends on the individual site, the equipment being installed, and the surrounding environment.

Do you need an air source heat pump noise survey?

If your proposed air source heat pump is located close to neighbouring properties or a noise-sensitive area, an acoustic assessment can help establish whether the installation is likely to meet relevant noise requirements.

A professional noise survey can provide useful information for planning applications, environmental assessments and the design of appropriate noise-control measures.

At APT Sound Testing, we can provide specialist acoustic advice and noise assessments for air source heat pump installations across the UK.

Contact us about an air source heat pump noise survey

If you need advice about sound testing or an air source heat pump noise assessment, get in touch with our team.

For more information, follow our blog or contact us at info@aptsoundtesting.co.uk or call APT Sound Testing directly on 01525 303905.

You can also find out more about our BS 4142 Noise Surveys and download our BS 4142 Noise Survey Checklist.

How can we help?

Why choose APT Sound Testing?

  • We strive to get you a pass
  • Competitive pricing
  • Friendly and proactive service
  • Experienced consultants
  • UKAS & ISO accredited
  • Fast response
  • Rapid turnaround of results
  • Nationwide coverage
  • Single pre-completion solution

If you’re looking for an experienced acoustic consultant or noise engineer, our team can help with noise assessments, acoustic advice and sound testing.

Air Tightness Testing for Data Centres
Air Tightness Testing for Data Centres

Air Tightness Testing for Data Centres

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Specialist Air Tightness Testing for COLO Data Centres & HAC Corridors

APT provides specialist air tightness testing for data centres, including COLO suites, data halls, containment pods and Hot Aisle Containment (HAC) corridors.

Our testing helps data centre operators verify containment performance, minimise unwanted airflow, maintain stable rack inlet temperatures and optimise cooling efficiency. As a UKAS-accredited air testing laboratory, APT provides accurate testing, detailed analysis and clear reporting to support commissioning, compliance and ongoing operational performance.

Our specialist testing identifies leakage paths, measures containment performance and highlights areas where improvements may be required to achieve the intended airflow separation within mission-critical environments.

Why Air Leakage Testing Matters in Modern Data Centres

Effective airflow containment is essential to maintain efficient, reliable data centre cooling. Uncontrolled air leakage can allow conditioned and return air to mix, reducing cooling effectiveness and creating unnecessary load on CRAH and CRAC systems.

Air tightness testing can help operators achieve:

  • Reduced cooling energy consumption
  • More stable rack inlet temperatures
  • Lower bypass airflow
  • Improved CRAH/CRAC efficiency
  • Better airflow separation
  • Improved cooling performance for high-density IT environments

Poorly sealed COLO pods, containment systems or HAC corridors can contribute to thermal instability, hot spots and increased cooling demand.

APT’s specialist testing provides measurable evidence of containment performance and helps identify areas requiring remedial work.

What We Air Test in Data Centres

APT can test a range of containment and airflow-controlled areas, including:

  • COLO containment zones
  • HAC corridors
  • Hot aisle containment systems
  • Pod-based containment systems
  • Return-air plenums
  • Data hall containment enclosures

Our testing can assess both operational leakage performance and construction air tightness, giving operators and project teams a comprehensive understanding of how effectively the containment system is performing.

Key Airtightness & Leakage Measurements

3% Leakage Criterion – Performance Testing

APT can assess HAC and COLO containment leakage against the specified project performance criterion, including a 3% leakage target based on the design IT airflow, where tthe projecthas bdopted fthis criterion

This provides a practical measure of how effectively the containment system is separating supply and return airflow under controlled test conditions.

Always confirm the applicable leakage criterion against the project’s design specification, commissioning requirements, and relevant standards.

ATTMA Air Tightness Testing – Construction Quality

APT can also measure air leakage relative to the enclosure’s surface area. This assesses the physical airtightness and construction quality of the containment system.

Testing can help identify defects such as:

  • Poorly sealed doors
  • Gaps around containment panels
  • Inadequately sealed joints
  • Cable and service penetration leakage
  • Floor and ceiling interface gaps
  • Construction defects within the enclosure

Using both performance-based leakage measurements and air permeability testing gives project teams a more complete picture of containment quality.

High-Pressure Integrity Testing for COLO & HAC Enclosures

In addition to operational air leakage testing, APT can undertake high-pressure integrity testing of COLO pods and HAC corridors.

A higher-pressure test, typically around 75 Pa where specified, can expose weaknesses that may not appear during lower-pressure operational testing.

Potential issues can include:

  • Panel deflection
  • Door movement or bowing
  • Seal failure
  • Roof-panel movement
  • Plenum interaction
  • Weaknesses around interfaces and penetrations

High-pressure testing provides additional information about the enclosure’s behaviour and integrity under increased pressure conditions. This can be particularly useful when assessing containment systems during commissioning or investigating performance concerns.

Blower Door Smoke Air Leakage Surveys

APT also provides specialist blower door smoke leakage surveys for COLO suites and HAC corridors.

This diagnostic approach combines controlled pressure testing with smoke tracing to identify the location and direction of unwanted air movement visually.

Smoke surveys can reveal leakage paths that may be difficult to locate through airflow measurements alone, including:

  • Leakage around containment doors and seals
  • Gaps between panels and roof sections
  • Cable tray and service penetrations
  • Leakage at floor interfaces
  • Plenum bypass routes
  • Construction defects behind or around IT equipment

By pressurising the containment area and introducing controlled smoke, our engineers can trace air movement and identify specific leakage locations.

Photographic evidence can then help contractors undertake targeted remedial sealing.

This makes blower door smoke surveys particularly useful during:

  • Data centre commissioning
  • Pre-go-live inspections
  • Defect investigations
  • Remedial works
  • Post-remediation validation

Our Data Centre Air Tightness Testing Process

APT’s testing process can include:

  1. Initial assessment of the containment area and test requirements.
  2. Test preparation, including identifying and temporarily sealing relevant openings where required.
  3. Blower door installation and controlled pressurisation of the test enclosure.
  4. ATTMA flow-curve analysis and leakage measurement.
  5. Operational pressure testing, including testing at 7.5 Pa where specified.
  6. Higher-pressure integrity testing, where required by the project.
  7. Smoke-tracing diagnostics to identify individual leakage paths.
  8. Leakage identification and photographic documentation.
  9. Clear reporting against the agreed project criteria.
  10. Practical recommendations for remedial sealing and retesting.

This gives project teams clear, actionable information on the airtightness and containment performance of their data centre environment.

Benefits of Air Testing COLOs & HAC Corridors

Specialist air tightness testing can help data centre operators and project teams achieve:

  • Reduced cooling energy consumption
  • Lower unwanted or bypass airflow
  • Improved CRAH/CRAC performance
  • More consistent rack inlet temperatures
  • Better airflow separation
  • Improved cooling performance for high-density loads
  • Greater confidence during commissioning
  • Identification of construction defects before handover
  • Verification of remedial works
  • Improved long-term containment performance

For mission-critical facilities, early leak detection can prevent avoidable cooling inefficiencies and increase confidence that the installed containment system is performing as intended.

Why Choose APT for Data Centre Air Testing?

APT specialises in air tightness testing for data centres, combining air testing expertise with an understanding of containment systems and the airflow requirements of mission-critical environments.

We provide:

  • Accurate leakage measurements
  • Detailed and easy-to-understand reports
  • Specialist diagnostic testing
  • Smoke leakage surveys
  • High-pressure integrity testing
  • Practical, contractor-friendly recommendations
  • Post-remediation verification
  • UK-wide testing coverage

Our services support data centre operators, COLO providers, M&E consultants, commissioning teams, main contractors and mission-critical facility managers.

APT provides testing across the UK, including major data centre locations such as London, Manchester, Poole, Dorset and other UK data centre hubs.

Get a Quote for COLO & HAC Air Tightness Testing

APT Sound Testing provides specialist airtightness testing for COLO suites, HAC corridors, and data centre containment systems across the UK.

Whether you require testing during construction, commissioning, pre-go-live checks, or after remedial works, our team can provide accurate measurements, diagnostic investigation, and clear reporting.

For more information or to discuss your data centre testing requirements:

Email: info@airpressuretesting.net
Telephone: 01525 303905

Contact APT today to discuss your COLO or HAC air tightness testing requirements and arrange a quotation.

Types of Sound Insulation Testing
Types of Sound Insulation Testing Needed on Flats

Types of Sound Insulation Testing Needed on Flats

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What Types of Sound Insulation Testing Are Needed on Flats?

One question clients regularly ask is: “What types of sound insulation testing are needed for flats?”

If you’re building a new block of flats or converting an existing property into separate dwellings, sound insulation testing is an important part of the Building Regulations process.

Under Approved Document E (ADE), separating walls and floors need to provide a suitable level of protection against noise travelling between homes. This includes everyday sounds such as conversations, television, music and footsteps.

The exact testing requirements depend on whether you’re dealing with a new-build development or a conversion. Still, two main types of sound insulation testing apply: airborne sound testing and impact sound testing.

Airborne Sound Insulation Testing

Airborne sound testing looks at how effectively a wall or floor stops sound travelling through the air.

Typical examples include speech, television, music and general household noise.

Where are airborne sound tests required?

Testing may be required between:

  • Living rooms in neighbouring flats
  • Bedrooms in neighbouring flats
  • Living rooms and bedrooms
  • Separating floors between flats

Airborne testing applies to both new-build flats and conversion projects.

How does an airborne sound test work?

During the test, a high-powered dodecahedron loudspeaker generates pink noise in one room. Class 1 sound meters then measure the sound levels in both the source room and the receiving room.

The results are used to calculate the airborne sound insulation performance, expressed as DnT,w + Ctr.

Minimum performance requirements

For residential developments, the typical minimum requirements are:

  • New-build flats: ≥ 45 dB
  • Conversions: ≥ 43 dB

These figures are an important part of demonstrating compliance with Approved Document E.

For a more detailed explanation, see our guide to Airborne Sound Testing.

Impact Sound Insulation Testing

Impact testing is slightly different. Rather than measuring sound travelling through the air, it measures noise created by physical impact on a separating floor.

Think about footsteps from the flat above, a chair being moved, or an object being dropped on the floor.

Where are impact tests required?

Impact testing is required for separating floors between dwellings, including conversions where a new flat is created above or below another dwelling.

How does impact testing work?

A calibrated tapping machine is placed on the upper-flat floor. The machine repeatedly drops a series of metal hammers onto the floor in a controlled pattern.

A Class 1 sound meter measures the resulting noise level in the room below.

The lower the measured result, the better the floor controls impact noise.

Minimum performance requirements

Typical limits are:

  • New-build flats: ≤ 62 dB
  • Conversions: ≤ 64 dB

If you’re dealing with an existing or upgraded floor, it’s particularly important to consider the floor construction and acoustic build-up before work starts.

For more information, see our guide to Sound Testing Floors in Flats.

Sound Testing Requirements for New-Build Flats

For a typical new-build flat development, you will generally need to consider:

  • Airborne testing of separating walls
  • Airborne testing of separating floors
  • Impact testing of separating floors

The number of tests required depends on the size and layout of the development, as well as the different types of separating construction being used.

For example, a small block may typically require something along the lines of:

  • 2 airborne wall tests
  • 2 airborne floor tests
  • 2 impact floor tests

However, confirm the exact testing schedule for each project rather than relying on a standard number of tests.

What about Robust Details?

If a development is constructed in accordance with an applicable Robust Details specification, sound testing may not be required for those particular separating elements.

However, you must follow the relevant Robust Details specification correctly, including the required registration and construction details. If the construction differs from the specification, testing may still be required.

Sound Testing Requirements for Conversion Flats

Conversions can be more challenging from an acoustic perspective.

Older buildings were not necessarily designed with the same levels of sound insulation expected between modern dwellings. Existing floors and walls can therefore perform very differently from one property to another.

For conversion projects, the required testing can include:

  • Airborne wall testing
  • Airborne floor testing
  • Impact floor testing

Why test before construction?

For conversions, we often recommend pre-construction sound testing where appropriate.

Testing the existing structure before carrying out acoustic upgrades can help establish how well the existing floor or wall performs. You can then use this information to determine what improvements are likely needed.

It can be much more cost-effective to identify an acoustic problem before installing the new floor or ceiling than to discover it during the final compliance test.

For further guidance, see our article on Designing for Sound Insulation.

Pre-Construction and Post-Construction Sound Testing

Sound insulation testing can be useful at different stages of a project.

Pre-construction testing

Pre-construction testing is particularly useful on conversion projects.

It allows you to assess the existing construction before acoustic upgrade work begins. The results can then help inform the design of the proposed floor or wall build-up.

Post-construction testing

Post-construction, or pre-completion testing, is carried out once the relevant construction work has been completed.

These tests provide the results needed to demonstrate compliance with Building Control where testing is required.

For a more detailed explanation of the process, see our guide to Pre- and Post-Construction Sound Insulation Testing Methodology.

Sound Testing for Lease Conditions and Hard Flooring

Building Regulations aren’t the only reason you may need sound testing in a flat.

Some lease agreements, particularly in London, include acoustic requirements for flooring alterations. This is especially common when replacing carpet with timber, laminate or engineered wood flooring.

In these situations, an acoustic assessment or sound testing may be required before and/or after the flooring is installed.

Depending on the lease and the requirements of the building, this could involve:

  • Pre-installation airborne and impact testing
  • Acoustic assessment and design advice
  • Installation of an appropriate acoustic floor system
  • Post-installation verification testing

Check the lease requirements before starting work. Getting the acoustic requirements right at the design stage can help avoid problems later.

For more information, see our guide to Sound Testing and Acoustic Design for Lease Conditions.

Why Choose APT Sound Testing?

At APT Sound Testing, we work with developers, builders, architects, landlords and property professionals across London and the South East.

Our services include:

  • UKAS-accredited testing laboratory status
  • ATTMA Level 2 certification
  • More than 22 years of experience in acoustics and sound insulation testing
  • Specialist experience with London and South East developments
  • Fast site attendance, often within 24–48 hours
  • Same-day certification
  • In-house sound testing engineers rather than subcontractors
  • Additional services including air testing, thermal imaging and diagnostic smoke surveys

Because our engineers test a wide range of residential projects, we can often identify potential problems quickly and provide practical advice on what may need to be addressed.

The aim is simple: help you get the testing right and avoid unnecessary project delays.

Need Sound Insulation Testing for a Flat?

Whether you’re developing a new block of flats, converting an existing property or carrying out alterations to a leasehold flat, getting the acoustic requirements right early can save time and money.

If you need sound insulation testing in London or the South East, or you’d like advice about acoustic design and compliance, get in touch with APT Sound Testing.

Email: info@aptsoundtesting.co.uk
Phone: 07775 623464
Website: www.aptsoundtesting.co.uk

We can often attend sites within 24–48 hours, with certificates available the same day where appropriate.

Replacing Carpet with Wooden Flooring
Sound Testing When Replacing Carpet with Wooden Flooring

Sound Testing When Replacing Carpet with Wooden Flooring

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Sound Testing When Replacing Carpet with Wooden Flooring

Replacing carpet with wooden, laminate or engineered timber flooring is a popular home improvement project in apartment buildings and flats. However, switching from a soft floor covering to a hard floor finish can significantly affect a property’s acoustic performance.

Many apartment leases include specific requirements for replacement flooring, often requiring the new floor construction to provide acoustic performance that is equivalent to, or no worse than, the original carpeted floor. Failing to meet these requirements can result in neighbour complaints, disputes with freeholders or managing agents, breaches of lease conditions and potentially expensive remedial works.

At APT Sound Testing, we help leaseholders, property managers, freeholders and flooring contractors manage the acoustic requirements associated with carpet-to-wood flooring conversions.

Our approach can include pre-works sound testing, acoustic design reviews and post-installation sound testing, providing a clear process for assessing and verifying the acoustic performance of the replacement floor.

For further guidance, see our sound testing roadmap for leaseholders.

Why Does Acoustic Performance Matter When Replacing Carpet?

Carpet and underlay can provide a useful degree of impact sound absorption, helping to reduce the transmission of everyday noises such as footsteps, dropped objects and movement across the floor.

Replacing carpet with a hard floor finish can change how impact sound is generated and transmitted through the building. Without an appropriate acoustic floor system, noise transmission to the flat below may increase.

This is why many residential leases contain flooring clauses requiring leaseholders to demonstrate that a replacement floor will provide an appropriate level of acoustic performance.

Before installing a new floor, it is therefore important to understand how the existing floor performs and what acoustic performance the proposed replacement system needs to achieve.

Stage 1: Pre-Works Sound Testing

The first stage establishes the acoustic performance of the existing carpeted floor.

APT Sound Testing can undertake airborne and impact sound insulation testing in accordance with the relevant recognised UK testing standards. These measurements provide an objective assessment of the existing floor construction before any alterations.

You can then use the results as a baseline when assessing the proposed replacement flooring.

Benefits of pre-works testing include:

  • Establishing the existing airborne sound insulation performance.
  • Measuring impact sound transmission through the existing floor.
  • Providing objective acoustic information for leaseholders, freeholders and managing agents.
  • Helping reduce the potential for disputes following installation.
  • Establishing an evidence-based performance benchmark for the replacement floor.

Testing before work begins is particularly valuable because it records the original floor’s performance before it is altered.

Stage 2: Acoustic Design Review for the Replacement Floor

Once the existing floor has been tested, the proposed flooring construction can be reviewed against the property’s and lease’s acoustic requirements.

Depending on the project, this may involve considering:

  • Acoustic underlays.
  • Floating floor systems.
  • Engineered timber flooring.
  • Laminate flooring systems.
  • Resilient acoustic mats.
  • Isolation layers.
  • Existing structural floor constructions.
  • Floor finishes and installation methods.

The objective is to identify a floor build-up that provides the required acoustic performance.

The acoustic performance of a flooring system can depend on more than the flooring product itself. The type of structural floor, acoustic layer, installation method and interaction between the different components can all be relevant.

An acoustic review before installation can therefore help identify potential issues at the design stage, when changes are generally easier and less expensive to make.

For further information about changing from carpet to a hard floor finish, see this guide to changing from carpet to a wood floor in flats.

Stage 3: Post-Installation Sound Testing

Once the new flooring has been installed, post-installation sound testing can be undertaken to assess the acoustic performance of the completed floor construction.

The testing can be carried out using the same general assessment methodology as the pre-works testing, allowing you to compare the results with the baseline measurements.

The final test report provides independent acoustic evidence of the completed floor’s performance.

Where testing is required as part of a lease condition or approval process, the report can also provide useful documentation for leaseholders, freeholders, managing agents and other parties involved in the project.

Why Test Before and After a Flooring Upgrade?

Testing before and after installation provides a more complete picture of the floor’s acoustic performance.

The pre-works test establishes the starting point, while the post-installation test assesses the completed floor.

This approach can help:

  • Identify the acoustic performance of the original floor.
  • Establish an objective benchmark.
  • Inform the selection of an appropriate flooring system.
  • Verify the performance of the completed installation.
  • Provide independent documentation for relevant parties.
  • Reduce uncertainty around acoustic compliance.

For leaseholders undertaking significant flooring alterations, obtaining objective acoustic evidence can be an important part of managing the project.

Sound Testing for Leaseholders Across London and the South East

APT Sound Testing has carried out floor replacement acoustic assessments for residential properties across London and the South East.

We work with a range of clients, including:

  • Leaseholders and apartment owners.
  • Property management companies.
  • Freeholders.
  • Resident management companies.
  • Flooring contractors.
  • Interior designers.
  • Architects.
  • Surveyors.

Our experience with residential flooring projects lets us provide practical acoustic advice alongside testing, helping clients understand the acoustic implications of switching from carpet to a hard floor finish.

UKAS-Accredited Sound Insulation Testing

APT Sound Testing is a UKAS-accredited testing laboratory operating to ISO/IEC 17025 for relevant testing activities.

UKAS accreditation provides independent recognition of the laboratory’s competence and the quality systems supporting its testing activities.

Our acoustic measurements are undertaken using appropriate calibrated equipment and established testing procedures by experienced acoustic professionals.

For projects that require independent, formally documented acoustic testing, using an appropriately accredited testing laboratory can provide additional confidence in the test results.

Planning to Replace Carpet with Wooden Flooring?

If you are planning to replace carpet with wooden, laminate, or engineered timber flooring in an apartment building, it is worth considering the acoustic requirements before removing the existing floor.

APT Sound Testing can provide a complete acoustic assessment service, including:

  • Pre-works sound testing
  • Acoustic design review
  • Review of proposed floor constructions
  • Acoustic advice on flooring systems
  • Post-installation verification testing
  • Acoustic reporting

Assessing the existing floor before work begins and testing the completed installation can provide a clear evidence trail throughout the flooring upgrade.

This can be particularly useful where the lease requires the replacement floor to maintain an appropriate level of acoustic performance.

Request a Quote for Leaseholder Sound Testing

Whether you are refurbishing a single apartment or managing flooring works across a larger residential development, APT Sound Testing can provide acoustic testing and advice tailored to your project.

Contact APT Sound Testing for a quotation and expert guidance on sound testing for carpet-to-wood flooring conversions.

Call: 07775 623464
Email: info@aptsoundtesting.co.uk
Website: www.aptsoundtesting.co.uk

Planning a carpet-to-wood flooring conversion? Contact APT Sound Testing before the work begins to discuss your acoustic testing requirements.

BS8233 Noise Assessments
Guide to a BS8233 Noise Impact Assessment

Guide to a BS8233 Noise Impact Assessment

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How to Prepare for a BS8233 Noise Impact Assessment

The accuracy of a BS8233 Noise Impact Assessment, also known as a BS8233 noise survey, depends heavily on how well you prepare the site before monitoring begins.

BS8233:2014 requires noise measurements to reflect the existing noise environment. This means the site must be in suitable condition for reliable, meaningful measurements.

Whether you are preparing for a planning application, discharging a planning condition, or assessing a proposed residential development, a little preparation can help the survey run smoothly and produce accurate results.

Below is a practical guide to preparing your site for a BS8233 noise assessment.

1. Ensure Safe and Unrestricted Access to the Monitoring Location

Position noise monitoring equipment in a secure, representative location. Before the survey begins, make sure the agreed monitoring position is easy to access.

You should:

  • Provide clear access to the agreed monitoring location.
  • Remove stored materials, vehicles or temporary structures that could obstruct the equipment.
  • Ensure the area is safe, dry and free from potential hazards.
  • Avoid locations where equipment could be accidentally damaged, moved or tampered with.

Provide suitable access so the acoustic consultant can position the microphone correctly and capture representative baseline noise levels.

2. Maintain Normal Site Conditions

For the results to be representative, the survey should reflect the site’s normal environmental conditions.

Where possible:

  • Do not change normal site operations unless specifically instructed by the acoustic consultant.
  • Avoid introducing temporary noise sources such as generators, radios or additional plant.
  • Ensure unusual activities are not taking place during the monitoring period.

The objective is to measure the typical ambient noise climate, not conditions that are unusually quiet or noisy.

3. Avoid Short-Term or Artificial Noise Sources

Temporary noise sources can affect the results and may make the recorded data less representative of typical conditions.

Before monitoring begins:

  • Switch off temporary plant or equipment that is not normally in use.
  • Avoid scheduling deliveries or construction activities during equipment installation where possible.
  • Keep windows and doors in their usual positions rather than changing them specifically for the survey.
  • Inform contractors and site staff that noise monitoring is taking place.

This helps ensure that the survey data provides a realistic indication of the existing noise environment relevant to the proposed development.

4. Confirm Power Availability Where Required

Many BS8233 noise surveys use autonomous Class 1 sound level meters that can operate independently for extended periods. However, some monitoring arrangements may require a mains electricity supply.

If mains power is required, ensure that:

  • A stable 240V supply is available.
  • There is a safe and suitable indoor location for any powered equipment.
  • The equipment does not need to rely on a generator, as generators can introduce additional noise and potential power fluctuations.

Your acoustic consultant should confirm any power requirements before the survey date.

5. Provide Accurate Site Information

Good information before the survey allows the acoustic consultant to plan the assessment effectively and select appropriate monitoring locations.

Where available, provide:

  • Site layout plans.
  • Proposed development drawings.
  • Operating hours for commercial premises.
  • Details of known noise sources, such as industrial premises, public houses, commercial premises or busy roads.
  • Site access instructions.
  • Contact details for the person responsible for providing access.

The more accurate the information provided, the easier it is to identify potential noise sources and determine appropriate monitoring positions and durations.

6. Keep the Monitoring Equipment Secure

If equipment is left on site for 24 hours or longer, it must remain undisturbed throughout the monitoring period.

To help protect the equipment:

  • Ensure the monitoring location is secure.
  • Notify relevant staff, tenants or site personnel that monitoring equipment has been installed.
  • Do not move, switch off or interfere with the equipment.
  • Keep vehicles, materials and other objects away from the microphone.

Moving or interfering with monitoring equipment can affect the validity and reliability of the recorded data.

7. Inform Neighbours or Occupants Where Necessary

For residential and mixed-use developments, it may be useful to inform occupants or nearby residents that noise monitoring will take place.

You can:

  • Let occupants know when you will install the equipment.
  • Explain that the monitoring equipment is safe and designed to operate unobtrusively.
  • Ask occupants not to move or interfere with the equipment.
  • Explain that the purpose of the survey is to establish the existing noise environment.

Good communication can help prevent accidental interference and ensure the equipment remains undisturbed.

8. Consider Weather Conditions

Weather conditions can affect outdoor noise measurements, particularly during heavy rain or strong winds.

Before the survey:

  • Avoid installing equipment during extreme weather where possible.
  • Ensure the microphone has an appropriate windscreen fitted.
  • Protect equipment from direct rainfall.
  • Follow your acoustic consultant’s advice if weather conditions become unsuitable.

The acoustic consultant will assess weather conditions and determine whether the measurements remain suitable for use in the assessment.

9. Allow Sufficient Monitoring Time

The required monitoring period will depend on the development, site conditions and requirements of the assessment.

For many residential developments, monitoring may include:

  • 24-hour noise monitoring to establish daytime and night-time noise levels.
  • Longer monitoring periods where site conditions or planning requirements make this appropriate.
  • Additional night-time measurements where required by the local authority or Environmental Health.

The site must remain accessible, and the monitoring equipment must remain undisturbed for the full agreed monitoring period.

BS8233 Noise Survey Preparation Checklist

Proper site preparation helps ensure the acoustic consultant obtains accurate, representative results.

Before the survey, make sure you have:

  • Provided safe and unrestricted access to the monitoring location.
  • Maintained normal site conditions.
  • Removed or avoided temporary noise sources where appropriate.
  • Confirmed power availability if required.
  • Supplied relevant drawings and site information.
  • Kept the monitoring equipment secure.
  • Informed occupants or site staff where necessary.
  • Maintained typical environmental conditions.
  • Considered weather conditions.
  • Allowed sufficient time for the agreed monitoring period.

Good preparation helps the acoustic consultant obtain reliable data to assess the site’s existing noise environment in accordance with BS8233:2014.

Need a BS8233 Noise Impact Assessment?

If you need a BS8233 Noise Impact Assessment, our UKAS-accredited acoustic consultants can help.

With more than 25 years of industry experience, we provide BS8233 noise surveys across London and the South East for residential developments, planning applications and noise-related planning conditions.

Whether you are submitting a planning application, discharging a noise condition or assessing a proposed development, we can provide professional noise monitoring and clear, practical reports designed to meet local authority requirements.

Email: info@aptsoundtesting.co.uk
Call APT Sound Testing: 01525 303905

You can also download our BS8233 Noise Assessment Checklist to help prepare your site before monitoring begins.

BREEAM Thermal Imaging Surveys:
BREEAM Thermal Imaging Surveys

BREEAM Thermal Imaging Surveys

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BREEAM Thermal Imaging Surveys: Thermographic Inspections

At APT Sound Testing, we have been providing professional BREEAM thermal imaging surveys for more than 10 years. Our experienced team uses high-resolution thermal imaging equipment to identify issues with insulation continuity, thermal bridging and heat loss, helping clients meet BREEAM requirements and improve building performance.

All of our thermal imaging surveys are carried out by Level 2 certified thermographers, providing clients with a professional and reliable assessment of their building.

What Is a BREEAM Thermal Imaging Survey?

Thermographic surveys are an important part of the BREEAM assessment process. BREEAM (Building Research Establishment Environmental Assessment Method) is one of the world’s leading methods for assessing the sustainability and environmental performance of buildings.

BREEAM sets standards for sustainable building design, construction and operation. Both BREEAM New Construction and BREEAM Domestic Refurbishment recognise the value of suitable thermographic surveys carried out by a suitably qualified Level 2 thermographer.

A thermal imaging survey uses specialist infrared cameras to detect temperature variations across the building envelope. These temperature differences can highlight areas where insulation may be missing, poorly installed or discontinuous, as well as potential thermal bridging and other defects.

What Can Thermal Imaging Surveys Identify?

A professional thermographic inspection can be used for a wide range of applications, including:

  • Insulation continuity checks
  • Thermal bridging
  • Areas of heat loss
  • Paths of air leakage
  • Building envelope defects
  • Underfloor heating inspections
  • Flat roof condition surveys
  • Data centre thermal surveys
  • Electrical and mechanical installation inspections
  • General building performance investigations

We provide thermal imaging surveys for both commercial and domestic properties, with the scope of each inspection tailored to the requirements of the project.

Non-Invasive and Non-Destructive Testing

One of the key benefits of thermal imaging is that it is a completely non-invasive and non-destructive inspection method. There is no need to open up walls, remove finishes or physically damage the building to investigate potential insulation defects.

Our high-resolution thermal imaging equipment allows our certified thermographers to identify temperature differences that may indicate areas requiring further investigation, providing valuable information without disrupting the building.

Experienced Level 2 Thermographers

Our team of certified professional engineers has extensive experience in thermal imaging, BREEAM assessments, construction, engineering, building maintenance and professional management.

We understand that every building and project is different. Our surveys are therefore planned around the specific requirements of your property, whether you need a BREEAM thermal survey for a new development, a refurbishment project or a wider building investigation.

We use professional, high-resolution thermal imaging equipment designed to provide detailed and accurate results. Following the inspection, we produce a comprehensive report and issue it electronically for convenient access.

Where project requirements allow, reports can normally be provided within 24 hours of completing the survey.

When Should a BREEAM Thermal Survey Be Carried Out?

A BREEAM thermographic inspection can generally be undertaken once the building envelope is complete and the heating system is operational. Suitable environmental and building conditions are important to ensure that the thermal survey can identify temperature differences effectively.

We can advise you on the requirements for your specific project and provide guidance on preparing the building ahead of the inspection.

A Complete Pre-Completion Testing Service

APT Sound Testing can provide more than just thermal imaging. We can also assist with a range of pre-completion and building performance testing requirements, including:

  • Air tightness testing for Building Regulations Part L
  • Sound insulation testing for Building Regulations
  • Planning noise surveys in accordance with BS 8233 and BS 4142
  • Server room integrity testing
  • Thermal imaging surveys for BREEAM and building performance assessments

By combining multiple testing services, we can provide a convenient, coordinated solution for construction and refurbishment projects.

What Do We Need to Provide a Quotation?

Getting started is straightforward. To prepare a quotation, we typically require a few details about your project, including:

  • The building location
  • Floor plans
  • Elevation drawings
  • The type and size of the building
  • The purpose and scope of the thermal survey

We can also provide an informative checklist to help you prepare your property and ensure the survey can be completed efficiently.

BREEAM Thermal Imaging Surveys Across London and the UK

Whether you require a BREEAM thermal imaging survey in London or elsewhere in the UK, APT Sound Testing can provide professional thermographic inspection services tailored to your project.

Our Level 2 certified thermographers have extensive experience across commercial, residential and construction projects. We focus on providing clear, accurate and useful reports that help identify potential issues and support the wider assessment and compliance process.

If you’re unsure whether a thermal imaging survey is required for your project, our team can discuss your requirements and advise you on the appropriate testing.

Arrange Your BREEAM Thermal Imaging Survey

If you require a professional BREEAM thermal imaging survey, contact APT Sound Testing today.

Call us on 01525 303905 or email info@aptsoundtesting.co.uk to discuss your project and request a quotation.

Our experienced team is ready to assist with your thermal imaging and pre-completion testing requirements from initial enquiry through to the completed report.

Air Tightness Testing
APT Air Tightness Testing Services

APT Air Tightness Testing Services

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APT Sound Testing – Air Tightness Testing Service

APT Sound Testing provides air tightness testing across London and the United Kingdom. We undertake air testing on all types of projects from single dwelling to the largest commercial buildings and data centres. We are one of the few companies that are UKAS accredited to undertake both Air & Sound testing in compliance to Building Regulations and Standards. This means we can undertake Air, Sound and Vent Testing Packages during the same visit which provides our clients with cost savings and improved on site co-ordination. Unlike many companies we do not subcontract our works.

Also known as blower door testing, air tightness testing, is the process of measuring the amount of air leakage from a building through the building envelope. To try and help our clients better understand and prepare for their air tightness testing, we have tried to explain and answer our customer’s most common questions. For more information on our air tightness testing services you can also visit our Services Page.

What is Air Tightness Testing for Building Regulations?
Air testing is mandatory in the United Kingdom and is governed by Part L of the Building Regulations, this split into two parts; for domestic properties Part L1A should be used and for commercial properties Part L2A should be referenced.

Building Regulations Part L states air tightness testing should be carried to check the air leakage that occurs through a buildings envelope. The air leakage test checks the amount of air that escapes through gaps or air leakage paths through the building fabric. If the building is more air tight, less energy will be being needlessly lost, thus lowering the carbon emissions of the building. Air testing also shows how efficient a building is at retaining conditioned air which will also put less straight on your mechanical and ventilation system. Failing to maintain adequate air tightness can lead to up to 50% of heat loss from within a building to the outside atmosphere.

What air leakage target do I need to achieve?
Most new dwellings and commercial buildings need to achieve an air leakage of 3m3/hr/m2 to 5m3/hm2, this rate would usually be acceptable by building control and your SAP assessor as an acceptable result, although you need to check each your designed SAP assessment as there may be items within your buildings design that that may affect this figure.

How long does the air test take?
Most air tightness tests can be completed in 1-2 hours if they pass straight away; however, tests can take much longer if they initially fail. It usually speeds up the process if customs prepare their buildings in-line with our air tightness checklist as its means we can start the testing as soon as we arrive on site instead of waiting for the client to tape up areas, or make upgrades to the building envelope.

We also offer a smoke testing service to locate the air leakage paths within a building envelope which can also take extra time; however this often allows our clients to seal and pass their building at the first attempt even if their building initially fails the air test.

How do you undertake an air tightness test?
The air tightness test is undertaken in-line with Building Regulations Part L1 & L2 and ATTMA TS1 & TS2. Basically we measure the pressure differential across the envelope of the building by means of the temporarily installation of a large fan inside a door panel. Thereafter, a range of static pressures and environmental readings are taken.

The fan is switched on and the air pressure in the property is gradually increased or decreased and the differential pressure is recorded at each step, usually from 25 Pa to 70 Pa. The total air flow required to achieve a pressure differential of 50 Pa is calculated and divided by the total building envelope area to provide the leakage rate in m3/h.m2@50Pa.

How do I prepare my building for the air test?
The more complete you’re building the more chance you have of passing the air tightness test at the first attempt. We send our and air test checklist with every quotation to help our client prepare for the testing. It is our aim to help clients pass their air test at the first attempt.

Basically you prepare the building in-line with our checklists and the items below, you will generally have a much better chance of passing the testing at the first attempt.

  1. The building envelope should be fully complete; this includes walls, floors and ceilings.
  2. All doors and windows must be fully fitted and able to shut tightly against their seals.
  3. All electric fittings must be installed and functional.
  4. All mechanical fittings must be installed and functional.
  5. Gaps within walls and floors must be sealed.
  6. All service penetrations must be fully sealed through the building envelope.
  7. Bathrooms and kitchens must be fully fitted and all service penetrations sealed.
  8. All mechanical ventilation turned off with grilles sealed.
  9. All trickle vents to windows and doors must be sealed.
  10. All fireplaces must be sealed.
  11. Ensure water is present in soil pipes.
  12. 240v power must be available on site.

If you need an airtightness test, please call us on 01525 303905 or email info@aptsoundtesting.co.uk for a no-obligation quote. If you need more information on how to prepare your building for the air test,, please download our airtightness testing checklist. Alternatively, please visit our website at www.aptsoundtesting.co.uk for more information on our pre-completion testing services.

Environmental Conditions for Thermal Imaging
Sound Testing Services Explained

Sound Testing Services Explained

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A Guide to Sound Testing Services

Airborne and Impact Sound is transmitted through most walls and floors by setting the entire structure into vibration. This vibration generates new sound waves of reduced intensity on the other side. The passage of sound into one room of a building from a source located in another room or outside the building is termed ”sound transmission”. 

Sound transmission loss or Sound Reduction Index, R dB, is a measure of the effectiveness of a wall, floor, door or other barrier in restricting the passage of sound. The sound transmission loss varies with frequency and the loss is usually greater at higher frequencies. The unit of measure of sound transmission loss is the decibel (dB). The higher the transmission loss of a wall, the better it functions as a barrier to the passage of unwanted noise across the dividing (acoustic) partitions.

Approved Document E stipulates that there are two types of sound insulation in buildings: airborne and impact. Airborne sound insulation is used when sound produced directly into the air is insulated and it is determined by using the sound reduction index. Impact sound insulation is used for floating floors and it is determined by the sound pressure level in the adjacent room below.

A sound insulation test of a separating partition will be considered as a pass if the airborne sound insulation is equal to or greater than the DnT,w + Ctr value shown for the appropriate dwelling in the table, for airborne testing in new builds properties a figure of 45dB or greater is required and for Impact testing 62dB and below. For conversion properties a figure of 43dB or greater is required and for Impact testing 64dB and below.

Sound Testing Services

What is DnT,w

DnT,w is an in-situ measured performance parameter which demonstrates the level of resistance to sound transmission between two adjacent spaces, such as flats or houses. The measurement will include both direct sound transmission and flanking sound transmission of the construction. Flanking transmission is the effect of sound travelling through the building and may be particularly evident where beams and joists bridge a common partition or along poorly isolated lightweight wall constructions.

The DnT,w of a separating wall or floor will typically be of the order 5 to 7 dB lower than the manufacturers specified Rw (single figure quantity of sound insulation) for the single element, due principally to the contribution from flanking sound transmission around the element when it is built on site – this should always be accounted for in the initial acoustic design.

What is Ctr

Ctr is the spectrum adaption term. It is a correction attributed to the sound insulation quantity to account for urban traffic noise.

What is L’nT,w

L’nT,w is an in-situ measured performance parameter which demonstrates the level of resistance to impact sound transmission between floors. The impact measurement includes both direct sound transmission and flanking sound transmission.

Weighted Sound Reduction Index Rw

When specifying the acoustic performance of an acoustic partition in a more general manner, it can be useful to describe the sound insulation by a single number. The weighted sound reduction index, Rw , is a rating method given in EN ISO 717-1. This standard fits a standard reference curve to the measured sound reduction index curve.

Within the EN ISO 717-1 standard, a rating method is also given where the Rw value is completed by two C-terms which are applied to two models of the noise spectra for various types of noise. These two terms, Rw + C and Rw + Ctr, also include the frequency range 100 – 3150 Hz but can be extended to 50 – 5000 Hz. As industrial and traffic noise often have high sound levels which are also below 100 Hz, it is recommended that the extended frequency area is used.

The summary value, Rw + C, gives the reduction value in dBA for a spectrum with a level which is equally high in all third-octave bands. This can be used for:

•             Highway road traffic travelling at speeds in excess of 80 km/h

•             Factories emitting mainly medium and high frequency noise

•             Living activities (talking, music, radio, TV)

•             Railway traffic at medium and high speed

•             Jet aircraft at a short distance

The summary value Rw + Ctr also gives the reduction value in dBA, spectrum with low-frequency dominance such as:

•             Disco music

•             Urban road traffic

•             Railway traffic at low speeds

•             Factories emitting mainly low and medium frequency noise

Both the impact and airborne insulation performance of floors and walls should be carefully considered from the start of the project to ensure that the minimum performance requirements for new and converted developments are met inline with Approved Document E

If you would like more information in regards to our sound testing and/or noise survey services, please contact us now at info@aptsoundtesting.co.uk.

APT Sound Testing and Acoustic Design
Sound Testing – Common Questions & Answers

Sound Testing – Common Questions & Answers

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Sound Testing – Common Questions & Answers

To try and help our clients better understand Sound Insulation Testing for Approved Documents E, we have collated the most common and questions (along with answers) clients have asked us over the last ten years. If you have further questions not contained within this article then please don’t hesitate to contact us.

What is Sound Insulation Testing?
Sound insulation is the property of a wall and /or dividing partition to resist the passage of noise. The sound Insulation testing is a method of quantifying the sound insulation performance of walls and/or floors. Sound Insulation testing can be carried out on party walls, party floors or facades of any building.

Do I need sound insulation testing on my Property?
One of the largest single reasons 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 is Approved Document E?

Approved Document Part E of the Building Regulations, sets out minimum standards for sound insulation performance to be achieved by party wall and party floors, you can achieve compliance with Part E by undertaking Pre-Completion Sound Testing

When is the Sound Testing carried out?
The Sound Insulation Testing is carried out when the buildings are 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 must be carried out before any soft coverings such as carpet have been laid to the floors. No furniture – such as beds or settees should be in the rooms during the sound testing as it will have an effect on the results. 

Are internal partitions 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; however, approved document E does state that internal partitions should achieve 40dB.

Do detached properties require sound testing for Part E of Building Regulations?
No, only attached properties require sound tests such as semi-detached dwellings or blocks of flats. Detached properties share no common partitions with any other properties.

How many sound insulation tests should I need 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.
  • 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.

Which plots selected for sound testing?
We usually specify the amount of sound insulation tests that is required on each project and this will be shown on a schedule within our fee proposal. This allows our clients to forward the schedule to building control to seek their approval prior to the test. We first look at the floor plans then work out a testing schedule taking into account testing through the projects ‘habitable rooms’ i.e. lounges & bedrooms where possible. 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 sound insulation testing.

How do I Prepare my Site for Sound Insulation Testing? 

APT Sound Testing always send out a sound testing checklist along 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.

How long will the sound testing take?

The time taken to undertake the sound insulation 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.

Will the sound insulation testing disrupt work on site? 
we require 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 or loud hammering etc.  

How do I know if I’m ready for a sound insulation test?
We send out a checklist with all quotations to allow our clients to check they are ready for the sound testing. Basically the plots should be at least at second fix stage – for further details please refer to our sound test checklist.

What sound testing equipment do you use?

We use the latest UKAS calibrated acoustic equipment, for ease of use and reliability. unlike many other companies we able inform clients if they have passed or failed straightaway whilst on site. This allows us to offer acoustic advice and collect detailed construction information whilst on site, in the event of wall and/or floors failing the sound testing.

What if I only have 110V and not 240V on site?

Unfortunately we cannot undertake the testing off 110V or localised generator power; we will need 240V to undertake the sound 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. We need to gain access to the neighbouring properties to undertake the sound test as we test the wall partition. You will also need to ensure that access is provided to the neighbouring properties throughout the sound testing.

Can you offer acoustic advice to help me to pass my sound testing?
APT 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 floor 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, we can then advise if any changes are required to lower the chance of sound test failures.

Rest Assured & Contact APT Sound Testing

We believe in working with our clients on all types of projects from small end of terrace developments up to large blocks of flats. 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 need sound insulation testing for your current project, please call our team on 01525 303905 or email info@aptsoundtesting.co.uk  We can provide you with expert advice and are happy to offer a free, no obligation quote along with our informative

checklist to help you prepare for the sound testing.

Sound Testing Consultancy
Acoustic Design & Sound Testing Consultancy

Acoustic Design & Sound Testing Consultancy

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APT Acoustic Design & Sound Testing Consultancy

APT provides acoustic design and sound testing and consultancy to help architects, developers and homeowners achieve the minimum requirements of Part E of the Building Regulations for new build and/or conversion projects. Sound transfer between walls in dwellings is a common problem and its often down to poor-quality construction – this is often down to the contractors installing party walls and floors being on price work and not taking time and care during the construction process resulting in poor workmanship.

Excess sound transfer occurs as a result of airborne noise such as tv, music, voices. The airborne sound wave strikes the wall, and the pressure variations cause the wall to vibrate resulting in noise. This noise (vibrational energy) is transferred through the wall partition and radiated as airborne sound.

The 4 elements of robust soundproof design to pass party wall sound testing
There are 4 main elements of soundproofing that need to be considered to pass sound testing through walls. It’s worth noting that all 4 elements throughout the process, all of which have a direct relation to the conduction and transmission of sound vibrations, they are: Mass, Decoupling, Absorption and Damping. If you incorporate all the four elements into your party wall design, then airborne sound transference should be kept to a minimum and you will pass your precomplation sound testing.

If all four elements are undertaken to your project, then there is a higher chance you will pass your party wall sound insulation testing at the first attempt.

Adding mass to pass party wall sound testing
The first element of a robust soundproofing design is the adding of mass. if the wall construction has a higher mass, the soundwave will struggle to vibrate the wall itself in order to permeate through it as it will have less movability, making it less probable for sound vibrations to travel through. One the most common ways to add mass by the inclusion of cement board or soundboard. This adds mass and makes the walls as heavy and thick as possible. Adding mass to walls is one of the easiest ways to decrease sound vibration, although will not reduce deep bass sounds from being heard.

Working out required mass required for wall to pass the sound insulation test can be quite difficult. For instance, the acoustic rating of a typical masonry wall increases from 45 dB to 50 dB when the thickness is increased from 100 mm (block laid on edge) to 215 mm (block laid flat). This doubling of mass does not need to be achieved by a doubling of thickness of a wall, as you can greatly increase the mass by opting for a masonry that has a minimum mass of 1900kg/m3 or (190/m2) whereas many lightweight blocks such as thermalite are only 500kg/m3 (50kg/m2), which can easily lead to sound test failure if used in the wrong situation such as the inner envelope construction and or a single skin construction for party walls.

It’s worth remembering for sound to conduct through a wall, it has to actually move or vibrate the party wall ever so slightly. A heavy mass wall is always much harder to move than a lighter wall. It is very important to note that a heavy wall will still vibrate, just not as easily as the lighter one, with this in mind we then need to use the 2nd element of soundproofing design which is the Decoupling of materials.

If all the above updates relating to adding mass are undertaken to your project, then there is a higher chance you will pass your party wall sound insulation testing at the first attempt.

Adding Decoupling to Pass Party Wall Sound Testing
The second element of a robust soundproofing design is decoupling. Basically, the term definition of decoupling is to separate objects or construction. With decoupling, you can introduce a cavity between two layers of drywall and/or masonry which separates the two wall constructions. By doing this, a layer of air is created in-between the walls which provides good sound insulation.

Decoupling materials within party wall construction is mostly done with resilient sound clips, resilient acoustic channel, or extra framing i.e., double stud or staggered stud walls. In most instances, sound vibrations will transfer easiest from material to material with solid connections, rather than through open space such as cavities.

In our experience coupled wall constructions usually have the worst sound insulation performance, this is because the sound has a solid sound transfer path via the direct fixed plasterboard to the framing and then through the direct fixed plasterboard on the other side. To improve the sound insulation performance of the party wall you need to introduce acoustic decoupling by reducing the number of connections by installing resilient sound clips, or by breaking the path entirely via the introduction of a 2nd wall leaf and cavity.

Resilient sound clips are small metal and rubber connections that attach to the timber of blockwork with screws. Resilient bars are then installed to the clips and plasterboard is then fastened to the channel. Sound clips provide acoustic decoupling by suspending the plasterboard on the resilient bars approx. 25-40mm from the timber or blockwork wall. This type of system is often favoured by developers as it has a minimal build up in comparison to constructing a double leaf wall with cavity and is much quicker to install.

If all the above decoupling updates are undertaken to your project, then there is a high change you will pass your party wall sound insulation testing at the first attempt.

Adding absorption to pass party wall sound testing
The third element of a robust design is the introduction of noise absorption materials within the party wall construction. In all cases, careful selection of good quality soundproofing insulation materials will contribute towards a successful sound test in compliance with Approved Document E. Absorption materials can be acoustic slabs and acoustic rolls.

The introduction of acoustic insulation materials such as Gyproc RW3 mineral wool (min mass 45kg/m3) can be a good place to start. The material is placed into the wall in order to absorb these soundwaves, but the insulation is not compressed. Acoustic insulation is good at removing low-level noise issues and can be quite easy to handle and install. The acoustic slabs are dense and effectively block out noise frequencies across party walls and floors in blocks of flats etc.

When you’re working on metal of timber stud walls, you can simply insert the acoustic slab straight onto the wall, making sure it’s fitted neatly between the metal /timber studs with no sagging or holes in the material. You can then install the rest of your acoustic solution such as resilient bars and acoustic plasterboard and apply an acoustic sealant around all gaps and holes.
If all the above absorption updates are undertaken to your project, then there is a higher chance you will pass your party wall sound insulation testing at the first attempt.

Adding damping to pass party wall sound testing
The 4th element of a robust soundproofing design (or acoustic design) is the introduction of noise damping within the party wall construction. Noise damping materials can be acoustic resilient layers and rubber panels which help to reduce vibration within the party wall construction. Dense recycled rubber panel systems are high performance wall soundproofing solution aimed at providing good noise damping performance. Unlike other acoustic solutions, this dense recycled rubber is fairly easy to install and will provide a reliable soundproofing-barrier.

Noise damping materials are usually quite easy to fit, as the acoustic rubber panels just need to be cut to size and stuck to the party wall covering the entire party walls surface. Proprietary adhesives are usually supplied with the rubber panels. The wall can then be finished off by adding two layers of acoustic plasterboard. When used correctly, this simple upgrade system, can improve the performance of a single skin brick wall by 7-10dB or achieve 46dB to 48dB Dnt, W +CTr which exceeds the requirements of Approved Document E for party walls 43dB Dnt, W +CTr in conversion projects.

If all the above damping upgrades are undertaken to your project, there is a higher chance of passing your party wall sound insulation testing at the first attempt.

Watch out for noise flanking transmission through party walls
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 via a continuous timber floor, but also through the supporting wall. This can be as simple as the party wall been built straight off the top of the timber floor finish, so the noise travels under the party wall via the continuous timber floor.

Another common noise flanking issue encountered on many office conversions, is the inclusion of lightweight (thermalite) blockwork in the original inner envelope and party wall construction. The mass of a blockwork wall should be approx. 1850kg/m2; however, a standard thermalite block may be as low as 450kg/m2, approx. one quarter of the recommend mass. This means the noise can pass to neighbouring flats via the lightweight walls, even when the party wall has been designed and built to pass Part E by a large margin.

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, due to onsite noise flanking resulting in sound test failure.

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

If all the above noise flanking considerations are employed on your contract, then there will be a much higher chance you will pass your party wall sound insulation testing at the first attempt.

Sound proofing masonry party walls to pass precompletion sound testing
There are many soundproofing solutions for masonry walls; however, it depends on what types of masonry have been used for the existing/new wall construction. To try and help you on your soundproofing journey, I have listed four acoustic solutions for masonry walls; however, each solution should be carefully checked with the material manufactures prior to onsite installation.
Here are three ways to soundproof a masonry party wall:

  1. For High mass Masonry – Check that all masonry and mortar pointing is complete, then apply a timber baton to the wall, then add resilient bars and a layer of 15mm sound insulation board. This only needs to be done to one side of the wall, where high mass masonry has been used.
  2. For Low mass Masonry – Check that all masonry and mortar pointing is complete, then apply a layer baton to the wall, then add resilient bars and RW45 acoustic insulation. finish with 15mm Sound Board. This needs to be done to both sides of the wall, where low mass masonry has been used.
  3. For Low mass Masonry (higher spec) – Check that all masonry and mortar pointing is complete, then apply a Gyproc G.L 1 wall lining solution to the wall, then add RW45 acoustic insulation to the inside of the metal frame. Then finish with two layers of Sound Board.
    Where high levels of sound insulation are required – Check that all masonry and mortar pointing is complete, then creating a new partition wall using 70mm met-sec with a cavity void to the party wall, fill the metal frame with acoustic insulation (min mass 60kg/m3) and finish with 2 layers of Acoustic Plasterboard. Unfortunately, this reduces the width of the room by up to 125mm.We can help with the party wall sound proofing design
    Sound Proofing Metal Party Walls to Pass Precompletion Sound Testing
    Metal stud walls are the most common type of interior wall; however, they are also extremely popular when it comes to party walls between dwellings. While metal walls are quick and easy to install, they’re really not very soundproof. Luckily, it’s possible to soundproof a stud wall, although it will take some acoustic design knowledge.
    One of the simplest ways of soundproofing a metal stud wall is to isolate each side of the wall and add mass. To soundproof a stud wall effectively, you can either add a completely independent wall in from of the existing wall, although you can also attain the required soundproofing levels by upgrading the existing wall.
    Here are three common ways to soundproof your metal party wall:
  4. For internal metal walls –fill the metal frame (min width 70-100mm) with acoustic insulation (min mass 45kg/m3) and install 1 x 15mm layer of soundboard to either side of the metal frame – please note this will not comply with the levels required for Approved Document E.
  5. For dividing metal party walls – fill the 100mm metal frame (with Rw45 acoustic insulation (min mass 45kg/m3) and attach “resilient channel” to each side of the studs and install 2 x 15mm sound board to either side of the wall.
  6. For high spec dividing metal party walls – use 2 x 70mm met-sec wall, with a 50mm cavity. Fill both metal frames with acoustic insulation (min mass 45kg/m3) and finish with a single layer of 15mm Acoustic Plasterboard.
    If the walls are existing i.e., it is a conversion project, you may need to gain access to the base and head of the party wall, to undertake the acoustic upgrades within floor and ceiling voids, this is also required to reduce the chance of flanking noise.

The importance of sample sound testing for Part E compliance
Unfortunately, retrofitting to improve sound insulation performance is difficult to achieve and not always 100 per cent successful. We always recommend you have sample sound testing undertaken between dwellings before embarking on expensive insulation works and on conversion projects as this provides an accurate overview of the sound insulation performance of existing walls and floors, as well as highlighting noise flanking issues.

For block of flats, it’s worth remembering that you will need to consider require both airborne and impact sound tests to ensure compliance with the 2014 Building Regulations Technical Guidance Document E (Sound). For houses you just need to consider walls.

Our roadmap to sound testing success
APT Sound Testing works with hundreds of builders, architects and property developers helping them with the acoustic design of their developments. Consequently, we are well placed to understand the challenges that adequately sound proofing party-walls poses to new build and/or conversion projects. Our roadmap to soundproofing success includes:

  1. Sample Sound Insulation Testing – We undertake sample sound testing to identify the sound levels for the existing party walls and floors. Thereafter a more targeted acoustic design can be undertaken to the partitions saving time and money through the construction process.
  2. Acoustic Consultancy – We have considerable experience in all matters related to architectural acoustic design and detailing. We can help develop the initial acoustic design of the project from the initial design scheme stage, in particular acoustic isolation, and interior acoustics. We also use the latest Norsonic equipment analysers and sound sources for conventional and binaural acoustic measurements.
  3. Site Visits – we undertake site visits which allow you (the client) and your contractor to feel confident about the outcome of testing at the end of the build. The site visits let us check that the installation teams are installing the acoustic materials as per manufacturers avoiding crucial onsite mistakes. You can often have a compliant design which still fails due to poor workmanship; the site survey visits negate the risk of sound test failure.
  4. Precompletion Sound Insulation Testing – We visit site and undertake the final pre-completion testing to ensure compliance with Building Regulations Part E and achieve building control sign off for the acoustic elements of the project.
    Using our friendly and proactive approach our acoustic engineers will work with you to achieve the required level of performance, however complex the project. Using the APT Sound Testing team, you will benefit from:
    a. all in one acoustic solution, that considers sample sound testing, acoustic design, and final pre-completion sound testing.
    b. vast amount of technical knowledge gained from providing consultancy on a wide range of projects for over 25 years (from small housing developments to multi-residential, mixed-use, or commercial sites) as well as experience from carrying out over 10,000 sound insulation tests.
    c. ongoing impartial independent advice – we are not affiliated with any acoustic manufacturers so the advice you receive is completely impartial. All correspondence with you remains strictly private and confidential.
    d. we endeavour to provide the cheapest acoustic solution to try and reduce costs and buildability issues. This will an off the shelf solution wherever possible.
    Getting the soundproofing design right from the word go, is key, and APT Sound Testing can help in all areas of acoustic design and sound insulation testing. For more information on our UKAS accredited sound testing or acoustic design services, please contact us at info@aptsoundtesting.co.uk or call us on 01525 303905.

Alternately for more information on how to prepare for your precompletion sound testing please download our sound testing checklist, or visit our website at www.aptsoundtesting.co.uk

Please Note: although we take every care to ensure the information was correct at the time of publication. Any written guidance provided does not replace the user’s professional judgement. It is the responsibility of the duty-holder or person carrying out the work to ensure compliance with relevant building regulations or applicable technical standards.