Residential Acoustic Design

Acoustic design to meet the requirements of the UK building regulations, national standards, and guidance. 

Noise Intrusion

Assessment of external noise impact.

Noise Emission

Assessment of operational phase noise emissions

Sound Insulation

Design of sufficient internal sound insulation.

From planning application, through design and construction, all the way to commissioning. Completely Sound Limited can support you during every phase of your project.


Acoustic Design

Although each project will have bespoke requirements, and detailed design will be dependent on many factors, not least the project specific design targets, but also the input from other sub consultants. However in general our aim during concept design (Stage 2), and developed design (stage 3), will be to provide the following information:

  • assessment of external noise impact, and specification of façade requirements;
  • assessment of operational phase noise emissions (from externally fixed plant, for example);
  • provision of sufficient internal sound insulation measures.

During technical design (stage 4) further detailed design will include specific measures to control noise from mechanical and electrical systems, specification of specific products (for instance, internal wall constructions and glazing specifications), as well as junction detailing to ensure adequate protection again flanking transmission, or noise break out from services.

For a free no obligation quote: 

T: 0845 508 0890

M: 0787 247 0205


Approved Document E

Approved documents are set out to provide guidance on setting out and delivering common building constructions. However, scope does exist to meet their minimum requirements by bespoke means.

The basis for any residential acoustic design comes from the UK Building Regulations. Part E of these regulations sets out the minimum performance standard to provide:

  • suitable protection against sound from other parts of the building and adjoining buildings;
  • protection against sound within a dwelling-house etc.
  • adequate reverberation within common internal parts of a building containing flats or rooms for residential purposes;
  • acoustic conditions for schools.
Approved Document E
Sound insulation

Performance Standards

Section 0 of approved document E provides the relevant acoustic design standards.

​The minimum values for Airborne sound insulation for separating walls, floors and stairs that have a separating function is 45 dB (DnT,w + Ctr).

In general terms, the performance of a partition system will be proportional to the mass of the system. For a simple, single skin partition, the performance of the wall will increase by approximately 5 dB, every time you double the mass.

In reality common partition systems are more complex than this, and changes in state (from solid to air), varying wall cavity sizes, junctions with other building elements, and the use of mineral fibre insulation, will all affect a partitions performance.


The maximum impact sound insulation values for floors and stairs that serve a separating function is 62 dB (L’nT,w). Mechanical resilience is king when discussing impact sound insulation. Unlike airborne transmission through walls, simply including a cavity is not as feasible within a floor system. A resilient layer within a floor can absorb mechanical energy, and will help to dampen vibrations before they are re-radiated as airborne noise into an adjacent space.

Material change of use

A slight relaxation of the sound insulation requirements occur in situations involving dwelling-houses, flats and rooms for residential purpose, formed by a material change of use. Such a change in use exists where there is a change in the purposes for which, or the circumstances in which, a building is used. Examples of this may include situation in which a building is used as a dwelling, or a part of it used as a flat or room for residential purpose, where previously this was not the case.


Pre-completion testing has applied to rooms for residential purposes, houses and flats formed by conversion of other building since 1 July 2004. Approved document E also provides the details of the requirements for pre completion testing, including the types of room to be tested, the grouping of similar construction types, and information to be reported.

Details of the procedure, and rating of results, for the purpose of testing within residential buildings, are found in ISO 140, and ISO 717 for Measurement, and rating of results, respectively.

Airborne sound insulation

Airborne sound insulation is measured in terms of the weighted standardised level difference (DnT,w). The difference level, in each 1/3 octave band, is standardised to a 0.5 second reverberation time, then weighted in order to provide a single figure value. In the process of calculation, an additional Spectrum Adaption Term (Ctr) is applied. This term was introduced in ISO 717-1:1996 ‘Rating of sound insulation in buildings and of building elements — Part 1: Airborne sound insulation’. It represents an A-weighted urban traffic noise spectrum, and can be thought of an a ‘low frequency correction’ to account for relatively low difference levels at the lower end of the assessment range.

Tests are performed using high volume white or pink noise, measured either side of the partition under assessment, in accordance with the relevant technical procedure. This is then corrected for background noise level, and reverberation time.



Tests are performed using high volume white or pink noise, measured either side of the partition under assessment, in accordance with the relevant technical procedure. This is then corrected for background noise level, and reverberation time.

Impact sound insulation

Impact sound insulation on the other hand is measured using the Weighted Standardised Impact Sound Pressure Level (L’nT,w). Again, standardised to account for a 0.5s reverberation time, and weighted in order to provide a single figure value.

From 1 July 2004, use of robust details in new houses and flats has been accepted as an alternative to pre-completion testing.

T: 0845 508 0890
M: 0787 245 0205


A: The Glider Business Centre,
65 Lowther Road,
Dunstable, LU6 3NL

T: 0845 508 0890
M: 0787 247 0205