Noise Insulation Between Flats: Soundproofing Guide
A comprehensive guide to noise insulation between flats, covering Building Regulations Part E, the difference between airborne and impact noise, soundproofing standards for new builds and conversions, acoustic improvement options, and managing agent responsibilities for handling noise complaints in blocks of flats. Understand your rights, your lease obligations, and how noise remediation works can be funded through the service charge.
What Is Noise Insulation Between Flats?
Noise insulation between flats refers to the acoustic performance of the separating walls, floors, and ceilings that divide one dwelling from another in a block of flats. Effective soundproofing is essential for ensuring that residents can enjoy their homes without being disturbed by noise from neighbouring properties. In purpose-built flats, the separating elements are typically designed to meet specific acoustic standards. In converted flats, achieving adequate sound insulation can be more challenging due to the limitations of the original building structure.
Poor noise insulation is one of the most common complaints in residential blocks and can lead to disputes between neighbours, formal noise complaints, and requests for the managing agent to intervene. The issue affects quality of life, property values, and the overall management of the building. Understanding the regulatory framework, the types of noise involved, and the available remediation options is important for leaseholders, freeholders, and managing agents alike.
This guide explains the Building Regulations that govern acoustic performance, the distinction between airborne and impact noise, the obligations contained in most leases, and the practical steps that can be taken to improve soundproofing between flats. For related guidance on neighbour disputes and behavioural noise, see our nuisance and anti-social behaviour guide.
Building Regulations Part E: Resistance to the Passage of Sound
Approved Document Part E of the Building Regulations sets out the requirements for resistance to the passage of sound in residential buildings in England and Wales. It applies to new-build developments, conversions, and material changes of use, and establishes minimum acoustic performance standards for separating walls and floors between dwellings.
Standards for New-Build Flats
For new-build flats, Part E requires separating floors to achieve a minimum airborne sound insulation value of 45 dB DnT,w+Ctr and a maximum impact sound level of 62 dB LnT,w. Separating walls must achieve a minimum airborne sound insulation value of 45 dB DnT,w+Ctr. These standards provide a reasonable level of acoustic comfort between dwellings in purpose-built blocks. Developers must demonstrate compliance through either pre-completion sound testing or registration with the Robust Details scheme.
Standards for Conversions
For converted flats and material changes of use, Part E applies slightly relaxed standards, recognising the practical constraints of working with existing building fabric. Separating floors in conversions must achieve a minimum airborne sound insulation of 43 dB DnT,w+Ctr and a maximum impact sound level of 64 dB LnT,w. Separating walls must achieve 43 dB DnT,w+Ctr. Even with these reduced thresholds, achieving compliance in older buildings can require significant intervention, including the installation of floating floors, independent ceilings, and additional layers of acoustic insulation.
Pre-Completion Sound Testing
Pre-completion sound testing is a requirement under Part E for demonstrating that separating elements meet the specified acoustic performance standards before a building is occupied. Testing is carried out by an accredited testing body and involves measuring both airborne and impact sound transmission through a representative sample of separating walls and floors. The alternative to site testing is registration with the Robust Details scheme, which allows developers to use pre-approved construction details that have been shown to consistently meet the required standards without the need for individual site testing.
Types of Noise: Airborne vs Impact
Understanding the difference between airborne noise and impact noise is essential for diagnosing noise problems in blocks of flats and selecting the appropriate soundproofing solution. The two types of noise behave differently and require different treatment approaches.
Airborne Noise
Airborne noise is sound that originates in the air and travels through walls, floors, and ceilings to reach an adjoining dwelling. Common sources of airborne noise in flats include speech, television and music, and barking dogs. The sound waves strike the surface of the separating element, causing it to vibrate and re-radiate the sound on the other side. The effectiveness of a wall or floor in resisting airborne noise depends on its mass, its stiffness, and whether it contains air gaps or acoustic absorption materials. Heavier, denser construction generally provides better airborne sound insulation.
Impact Noise
Impact noise is generated when an object physically strikes a surface, sending vibrations directly through the building structure. The most common source in flats is footfall, particularly on hard surfaces such as laminate, tile, or engineered timber. Other sources include dropped objects, children running, and furniture being dragged. Impact noise is often the most difficult to address because vibrations travel through the structure rather than the air. The most effective approach to reducing impact noise is a floating floor or resilient layer that decouples the walking surface from the structural floor beneath.
Flanking Noise
In addition to direct transmission, flanking noise bypasses the main separating element and travels through connected structures such as external walls, floor edges, service voids, and ductwork. Even where the main separating floor or wall has been upgraded, flanking paths can significantly reduce overall performance. Addressing flanking noise requires careful detailing at junctions and may involve isolating the flanking elements separately. This is a particular challenge in converted buildings where the original construction was not designed for acoustic separation.
Common Noise Complaints and Managing Agent Response
Noise complaints are among the most frequent issues raised by leaseholders in blocks of flats. They can relate to behavioural noise, structural inadequacy, or a combination of both. Managing agents play a central role in investigating complaints, enforcing lease covenants, and recommending practical solutions. For broader guidance on nuisance issues, see our nuisance and anti-social behaviour guide.
Hard Flooring and Footfall Noise
One of the most common complaints involves impact noise caused by leaseholders replacing carpeted floors with hard surfaces such as laminate, tile, or engineered wood. Without adequate acoustic underlay, hard flooring dramatically increases the transmission of footstep noise to the flat below. Many leases contain covenants requiring leaseholders to maintain carpet or to obtain consent before installing hard flooring, and to ensure that any replacement achieves equivalent acoustic performance. The managing agent can enforce these covenants and require the leaseholder to install appropriate acoustic underlay or to reinstate soft floor coverings.
Music, Television, and Speech Noise
Airborne noise from music, television, and loud conversation is another frequent source of complaints. Where the noise is caused by antisocial behaviour or unreasonable volume levels, the managing agent can write to the occupier reminding them of their lease obligations regarding nuisance and quiet enjoyment. Where the noise is at normal domestic levels but is still audible due to poor sound insulation, the issue is structural rather than behavioural, and the solution lies in improving the acoustic performance of the separating elements. Rules governing communal areas may also be relevant where noise emanates from shared spaces.
Building Services Noise
Noise from building services, including boilers, water pipes, lift machinery, and communal heating plant, can be a significant source of disturbance. This type of noise is typically the responsibility of the freeholder or management company, as it relates to communal infrastructure. Solutions include anti-vibration mounts, acoustic enclosures, lagging of pipework, and replacement of ageing equipment. The managing agent should investigate all reports of building services noise and commission specialist advice where the source is unclear.
Acoustic Improvement Options
Where noise insulation is found to be inadequate, there are a range of acoustic improvement options available. The right solution depends on the type of noise, the existing construction, and the level of improvement required. These works may qualify as major works and should be planned and consulted on accordingly.
- Floating floors: a decoupled floor system on a resilient layer above the structural floor, reducing impact noise transmission to the dwelling below
- Resilient bars and independent ceilings: metal channels fixed to ceiling joists supporting a new plasterboard layer, breaking the direct vibration path
- Acoustic mineral wool insulation: dense mineral fibre installed within floor voids, wall cavities, and ceiling spaces to absorb sound energy
- Acoustic underlay for hard flooring: specialist resilient layers beneath laminate, tile, or engineered timber to reduce footfall impact noise
- Independent stud walls: a new wall on a separate frame alongside the existing party wall, with an air gap and acoustic insulation between
- Acoustic sealant and gap treatment: sealing gaps around service penetrations, pipe runs, sockets, and wall-floor junctions to prevent sound leakage
- Anti-vibration mounts and acoustic enclosures: isolating mechanical plant and lift equipment from the building structure to reduce vibration transmission
- Mass-loaded vinyl barriers: a thin but dense membrane added to walls and ceilings to increase mass and improve airborne sound insulation
The choice of solution should always be informed by an acoustic survey carried out by a qualified acoustician. This ensures that the correct noise paths are identified and that the proposed treatment will deliver the required level of improvement. For guidance on how these works are funded and managed, see our service charge guide.
Lease Covenant Obligations Regarding Noise
Most residential leases contain covenants that are directly relevant to noise insulation and soundproofing between flats. These covenants impose obligations on leaseholders and give the freeholder or managing agent the authority to enforce standards of behaviour and property maintenance that protect the acoustic environment of the building.
Nuisance and Annoyance Covenants
Almost all leases contain a covenant not to cause nuisance or annoyance to other occupiers. This broad obligation covers excessive noise from music, parties, and any activity that unreasonably disturbs neighbours. The managing agent can rely on this covenant to require a leaseholder to reduce noise levels and, if the leaseholder fails to comply, can escalate through formal breach of covenant proceedings. Our nuisance and anti-social behaviour guide explains the enforcement process in detail.
Floor Covering Covenants
Many leases require leaseholders to maintain adequate floor coverings, typically specifying that floors must be carpeted or that hard flooring may only be installed with the landlord's consent and subject to conditions regarding acoustic performance. These covenants exist specifically to protect downstairs neighbours from impact noise. Where a leaseholder has installed hard flooring in breach of the lease, the managing agent can require them to install acoustic underlay or to reinstate carpet. Enforcing floor covering covenants is one of the most effective tools available for addressing noise complaints in blocks of flats.
Alterations Covenants
Leases typically require leaseholders to obtain the landlord's consent before carrying out alterations to their flat. This is particularly important for noise insulation because alterations affecting the building structure, such as removing or modifying separating floors and ceilings, can compromise acoustic performance. The managing agent should ensure that any consent includes conditions relating to sound insulation standards and may require acoustic testing before and after the works.
Service Charge Implications of Noise Remediation Works
Where noise remediation works involve the building structure or communal areas, the cost will usually be recoverable through the service charge. This raises important questions about consultation, reasonableness, and the rights of leaseholders to challenge the costs.
Section 20 Consultation
If the cost of acoustic improvement works exceeds 250 pounds per leaseholder, the freeholder or managing agent must carry out the statutory consultation process under Section 20 of the Landlord and Tenant Act 1985 before proceeding. This involves notifying leaseholders of the proposed works, inviting observations and contractor nominations, obtaining estimates, and providing a further opportunity for comment before the contract is awarded. Failure to consult limits the amount recoverable to 250 pounds per leaseholder. The major works guide provides a detailed overview of the Section 20 process.
Reasonableness of Costs
Leaseholders have the right to challenge whether the costs of noise insulation works have been reasonably incurred under Section 19 of the Landlord and Tenant Act 1985. The managing agent must demonstrate that the works are necessary, the specification appropriate, and the costs reasonable. Commissioning a professional acoustic survey before specifying works helps establish the case for the proposed solution and supports the reasonableness of the expenditure if challenged at the Tribunal.
Reserve Fund Contributions
Where a building has an established reserve fund and the lease permits its use for improvement works as well as repairs, acoustic improvement works may be funded from the reserve. This reduces the immediate financial impact on leaseholders by spreading the cost over time. Managing agents should plan ahead for known acoustic issues and include provision for noise remediation in the long-term maintenance plan and service charge budget.
Frequently Asked Questions About Noise Insulation Between Flats
What are the Building Regulations for noise insulation between flats?
Building Regulations Approved Document Part E sets out the requirements for resistance to the passage of sound in residential buildings in England and Wales. Part E applies to new-build flats, conversions, and material changes of use. It specifies minimum acoustic performance standards for separating walls and floors between dwellings, covering both airborne sound insulation and impact sound insulation. For new-build flats, separating floors must achieve a minimum airborne sound insulation value of 45 dB DnT,w+Ctr and a maximum impact sound level of 62 dB LnT,w. Separating walls must achieve a minimum airborne sound insulation value of 45 dB DnT,w+Ctr. Conversions have slightly relaxed standards, with separating floors requiring 43 dB DnT,w+Ctr for airborne sound and 64 dB LnT,w for impact sound. Pre-completion sound testing or Robust Details registration is required to demonstrate compliance before a building is occupied.
Who is responsible for soundproofing between flats?
Responsibility for soundproofing between flats depends on the terms of the lease, the nature of the building, and how the noise issue has arisen. In general, the structure of the building, including separating floors and walls, is the responsibility of the freeholder or the management company acting on behalf of leaseholders. If the original construction fails to meet adequate acoustic standards, the freeholder or developer may bear responsibility for remediation. However, if a leaseholder has carried out alterations to their flat that have compromised the sound insulation, such as removing carpets to expose hard flooring without installing adequate acoustic underlay, that leaseholder may be responsible for restoring the acoustic performance. The lease will often contain covenants relating to floor coverings and nuisance that govern these obligations. Managing agents play a key role in mediating between parties and enforcing lease covenants where noise complaints arise.
Can I make a noise complaint to my managing agent?
Yes, you can and should report persistent noise issues to your managing agent. Managing agents are responsible for enforcing the terms of the lease, which typically include covenants against causing nuisance or annoyance to other occupiers. When you make a noise complaint, the managing agent will usually investigate the source and nature of the noise, review the relevant lease covenants, and contact the leaseholder or tenant responsible. Common complaints include impact noise from hard flooring, loud music, television noise transferring through party walls, and noise from building services such as boilers and pipework. The managing agent may request that the offending party takes steps to reduce the noise, such as installing acoustic underlay or observing quiet hours. If the issue relates to structural inadequacy rather than behaviour, the managing agent may need to commission an acoustic survey to assess the building fabric and recommend improvement works.
What is the difference between airborne and impact noise in flats?
Airborne noise and impact noise are the two principal categories of sound transmission between flats, and they behave differently. Airborne noise is sound that travels through the air before striking a wall or floor and passing through to the adjoining dwelling. Common examples include speech, television and music noise, and barking dogs. The effectiveness of a wall or floor in resisting airborne noise is measured in decibels using the DnT,w+Ctr metric. Impact noise, by contrast, is generated when an object physically strikes a surface, causing vibrations that travel directly through the structure. Common examples include footsteps, dropped objects, furniture being moved, and children running. Impact noise performance is measured using the LnT,w metric, where a lower value indicates better insulation. Addressing airborne noise typically involves increasing the mass or adding acoustic absorption to walls and ceilings, while impact noise is best reduced at source through floating floors, resilient layers, and appropriate floor coverings.
How much does soundproofing between flats cost?
The cost of soundproofing between flats varies significantly depending on the type of noise being addressed, the construction of the existing separating elements, and the level of improvement required. As a general guide, installing a floating floor system with acoustic insulation and a resilient layer costs between 50 and 100 pounds per square metre, depending on the specification. Adding an independent ceiling with resilient bars and acoustic plasterboard typically costs between 60 and 120 pounds per square metre, including labour and materials. For walls, an independent stud wall with acoustic insulation can cost between 40 and 80 pounds per square metre. A full acoustic survey to assess the current performance and recommend solutions typically costs between 500 and 1,500 pounds depending on the size of the property and number of elements tested. These costs can be substantial when applied across multiple flats, which is why service charge funding and Section 20 consultation are important considerations for blocks of flats.
Can noise insulation works be funded through the service charge?
Whether noise insulation works can be funded through the service charge depends on the terms of the lease and the nature of the works. If the separating floors and walls form part of the building structure, and the lease permits the landlord or management company to carry out works to maintain, repair, or improve the structure, then the cost of acoustic improvement works may be recoverable through the service charge. Where the cost of the works exceeds the Section 20 consultation threshold, currently 250 pounds per leaseholder, the landlord must follow the statutory consultation process under Section 20 of the Landlord and Tenant Act 1985 before the works are carried out. Failure to consult properly limits the amount recoverable from each leaseholder to 250 pounds. Leaseholders have the right to challenge whether the costs are reasonably incurred through the First-tier Tribunal. It is also possible to fund acoustic works through the reserve fund if one has been established and the lease permits its use for improvement works as well as repairs.
Need Help With Noise Insulation in Your Block?
Whether you are a leaseholder dealing with noise complaints and want to understand your rights, a director seeking advice on acoustic improvement works, or you need help managing noise insulation issues in a converted block or purpose-built development, Block is here to help. Our experienced team manages soundproofing and noise remediation projects across hundreds of buildings nationwide.