|Number of credits available||Minimum standards|
Building type dependent
To ensure the building's acoustic performance, including sound insulation meets the appropriate standards for its purpose.
This issue is split into two parts:
The following is required to demonstrate compliance:
|1||A suitably qualified acoustician (SQASuitably qualified acoustician) (see Relevant definitions) is appointed by the client at the appropriate stage in the procurement process (but no later than completion of outline design) to provide early design advice on:|
|1.a||External sources of noise impacting the chosen site|
|1.b||Site layout and zoning of the building for good acoustics|
|1.c||Acoustic requirements for users with special hearing and communication needs|
|1.d||Acoustic treatment of different zones and façades.|
|2||All unoccupied spaces comply with the indoor ambient noise level targets as detailed in the more rigorous of criteria 2.a or 2.b:|
|2.a||Indoor ambient noise level targets within national building regulations or other appropriate good practice standards|
|2.b||Where national building regulations or good practice standards do not exist for the building type or do not provide indoor ambient noise targets, the indoor ambient noise levels comply with 'good practice' criteria levels outlined in Table 20|
|3||A SQA carries out ambient noise measurements to ensure that the relevant spaces achieve the required levels. Where the measurements identify that spaces do not meet the standards, remedial works are carried out and the measurements repeated to confirm that the levels are achieved prior to handover and occupation.|
|4||The sound insulation between acoustically sensitive rooms and other occupied areas comply with the privacy index, as detailed in the more rigorous of criteria 4.a or 4.b:|
|4.a||Sound insulation between acoustically sensitive rooms and other occupied areas comply with targets within national regulations or other appropriate good practice standards|
|4.b||Where relevant national regulations or good practice standards do not exist for the building type or do not provide sound insulation performance targets, the sound insulation between acoustically sensitive rooms and other occupied areas complies with the following privacy index: Dw + LAeqT > 75. Where privacy is viewed to be critical by the client or design team (e.g. doctor's consulting room, consulting room within a bank) or where the room is adjacent to a noisy space such as a music room, the area should comply with an enhanced privacy index: Dw + LAeqT > 85.|
|5||The source and receive room sound pressure levels from which Dw is determined are measured in accordance with (EN) ISO 140-4:1998 and rated in accordance with (EN) ISO 717-1:1996. Measurements must be based on finished, but unfurnished rooms, accounting for, and to include the effect of, any carpets and acoustically absorbent ceilings specified.|
|6||Teaching and learning spaces with lightweight roofs and roof glazing demonstrate that the reverberant sound pressure levels in these rooms are not more than 25 dB above the appropriate limits given in Table 20|
|7||Rooms or areas used for speech (including meeting rooms and rooms for public speaking) or rooms used for music performance and rehearsal, achieve reverberation times as detailed in the more rigorous of criteria 7.a or 7.b and 7.c:|
|7.a||Demonstrate that the reverberation time or equivalent absorption area for relevant spaces complies with targets within relevant national regulations or other appropriate good practice standards|
|7.b||Where relevant national regulations or good practice standards do not require the control of reverberation time, achieve reverberation times compliant with Table 21|
|7.c||In addition, if relevant to the assessed building, all areas used for teaching, training and educational purposes achieve reverberation times compliant with Table 22|
|8||The building meets the acoustic performance standards and testing requirements as detailed in the more rigorous of EITHER:|
|8.a||Airborne and impact sound insulation values comply with the performance improvement standards, as compared to the relevant national regulations outlined in Table 23|
|8.b||Airborne and impact sound insulation levels comply with the performance standards outlined in Table 24 unless otherwise stated within these criteria.|
|9||A programme of pre-completion testing is carried out by a compliant test body EITHER:|
|9.a||Based on the normal programme of testing described in the relevant national regulations for every group or sub-group of rooms for residential purposes; this must demonstrate that the performance standards detailed within this issue are achieved OR|
|9.b||Where there are no relevant national regulations in place, or they require laboratory measurements to demonstrate compliance, the programme of on site pre-completion testing must be carried out based on the 'Frequency of testing required' guidance (see calculation procedures in Methodology) for every group or sub-group of rooms.|
|10||The number of credits awarded will depend on improvement to the national regulations determined according to Table 23 or Table 24. Where commercial space is below the residential space, only airborne sound insulation tests will be required.|
Function of area
Indoor ambient noise level*
General spaces (staffrooms, restrooms)
≤ 40 dB LAeqT
|Single occupancy offices||≤ 40 dB LAeqT|
|Multiple occupancy offices||40-50 dB LAeqT|
|Meeting rooms||35-40 dB LAeqT|
|Receptions||40-50 dB LAeqT|
|Spaces designed for speech, e.g. teaching, seminar or lecture rooms||≤ 35 dB LAeqT|
|Concert hall, theatre or auditoria||≤ 30 dB LAeqT|
|Informal café or canteen areas||≤ 50 dB LAeqT|
|Catering kitchens||≤ 50 dB LAeqT|
|Restaurant areas||40-55 dB LAeqT|
|Bars||40-45 dB LAeqT|
|Retail areas||50-55 dB LAeqT|
|Manual workshops||≤ 55 dB LAeqT|
|Sound recording studios||≤ 30 dB LAeqT|
|Laboratories||≤ 40 dB LAeqT|
|Sports halls or swimming pools||≤ 55 dB LAeqT|
|Library areas||40-50 dB LAeqT|
|Hotel bedrooms||< 35 dB LAeqT|
|* Where ranges of noise levels are specified and privacy is not deemed by the final occupier to be an issue, it is acceptable to disregard the lower limit of the range and consider the noise level criteria to be lower than or equal to the upper limit of the range1 BS 8233 Sound insulation and noise reduction for buildings - Code of practice, 2014.|
Reverberation time T*
|*Where the reverberation times stated above or in the referenced documents are not appropriate for the type of space or building being assessed, the acoustician must confirm why this is the case. In addition, the acoustician must set alternative appropriate reverberation times at the design stage and provide these to demonstrate compliance.|
Type of room
Small (fewer than 50 people)
Large (more than 50 people)
|Control room for recording||< 0.5|
|Audio-visual, video conference rooms||< 0.8|
|*Tmf is the arithmetic average of the reverberation times in the 500 Hz, 1 kHz and 2 kHz octave bands2Building Bulletin 93: Acoustic Design in Schools, A Design Guide, 2004, UK Department for Education & Employment.|
|Credits awarded according to improvement over national legislation, standard or other defined baseline|
Airborne sound insulation
Impact sound insulation
|Individual bedrooms & self-contained dwellings|
|1||Insulation values are at least 3dB higher||Insulation values are at least 3dB lower*|
|3||Insulation values are at least 5dB higher||Insulation values are at least 5dB lower*|
|4||Insulation values are at least 8dB higher||Insulation values are at least 8dB lower*|
|*The index used to express impact sound insulation is usually based on the level of transmitted impact sound, such that a lower measured value indicates greater resistance to impact sound transmission. If the converse for the locally defined national index is true, the credit award will be based on the same performance increase as detailed for the airborne sound insulation and an accompanying statement from a SQA.|
|Credits awarded according to sound insulation performance standards|
Airborne sound insulation
DnT,w + Ctr dB (minimum values)
Impact sound insulation
L'nT,w dB (maximum values)
|Individual bedrooms & self-contained dwellings|
Shell and core (non-residential and residential institutions only)
|Applicable assessment criteria|
Indoor ambient noise criteria:
Both options: All criteria relevant to the building type and function apply (an alternative method to demonstrate compliance applies in this instance, refer to CN1.1 for further information).
Sound insulation and reverberation criteria:Both options: These criteria are not applicable.
Refer to Appendix D – Shell and core project assessments for a more detailed description of the shell and core assessment options.
|Alternative means of demonstrating compliance|
The basic built form has a large impact on the acoustic performance of the building, and in the case of a shell only or shell and core development, this aspect of the build would be outside the control of the tenant. A SQA must carry out a quantifiable assessment of the specification of the build form, construction and any external factors that are likely to affect the indoor ambient noise levels. From this assessment, the SQA must confirm that given a typical arrangement and fit-out specification for the building type, the development is likely to meet the levels required to demonstrate compliance with the BREEAM criteria.
Where the specific room functions and areas within the building are yet to be defined, the acoustician must base their assessment on the most sensitive room type likely to be present in the building, as a worst case. For example, in a retail assessment, where there are likely to be offices, the acoustician should make an assessment based on this scenario.
One credit can be awarded where this has been achieved.
Residential - Partially fitted and fully fitted
|Applicable assessment criteria - Single and multiple dwellings|
Refer to Appendix E – Applicability of BREEAM New Construction to single and multiple dwellings, partially and fully fitted for a more detailed description of residential assessment options.
default case - Applies to detached dwellings
|Four credits are available where there are no attached dwellings.|
Attached multiple dwellings where separating walls or floors occur only between non-habitable rooms
Three credits are available.
Note: these criteria apply only to walls, floors and staircases that perform a dwelling to dwelling separating function. Internal partitions are beyond the scope of this issue.
|Other appropriate good practice standards or regulations||As detailed in the assessment criteria it is possible to use a national or local equivalent to the BREEAM requirements stated; however this must be approved by BRE Global. The Approved standards and weightings list can be used to check for previously approved standards or to propose a new national or local standard.|
|Building types without areas 'used for speech'||Where a building type does not have areas 'used for speech', it does not need to comply with the relevant 'reverberation times' criteria. In these instances, the credit available for reverberation can be awarded by default where the building complies with the indoor ambient noise level and sound insulation criteria.|
|Acoustically sensitive rooms|
Where the term 'acoustically sensitive rooms' is referenced in this BREEAM issue, it refers to any room or space the design team or client deems to be acoustically sensitive for the purposes of privacy, which may include the following types of spaces or rooms (where specified):
|Remedial works||Where a programme of pre-completion testing identifies that spaces do not meet the standards, remedial works must be carried out prior to handover and occupation, and the spaces retested to ensure compliance. Remedial works must be carried out to all affected and potentially affected areas, including rooms or spaces previously untested of a similar construction and performance requirement. The test report, or covering correspondence, should include a clear statement that the testing is in accordance with the required standard (where specified) or the BREEAM criterion 3 and Methodology section, and include the relevant pass or fail criteria.|
|Privacy index||To increase the ambient noise level, where privacy is required or the ambient targets include a minimum as well as maximum limit, an artificial sound source or sound masking system may be required. Any artificial sound source or sound masking system should be installed and in operation at the time of the acoustic testing to demonstrate compliance.|
|Reverberation times||Where the reverberation time required by the relevant standard is not appropriate for the type of space or building being assessed, the SQA must confirm why this is the case. In addition the SQA must set alternative appropriate reverberation times at the design stage and provide these to demonstrate compliance.|
Programme of testing
It is not acceptable to undertake a shorter test programme due to site readiness on the day of testing. If this issue arises additional testing should be scheduled. It may be that testing at less than the typical regime identified would be acceptable in some instances. Where this is the case, clear reasoning must be provided by the compliant test body prior to awarding the credits.
|Building type specific|
Long term stay residential institutions.
Rooms not covered by residential criteria.
Long term stay residential institutions often contain a mixture of 'non-residential' areas such as offices, small retail outlets, meeting rooms etc. and residential areas, e.g. self-contained dwellings or rooms for residential purposes.
Where less than 5% of the floor area of the assessed building includes 'non-residential' areas, these areas do not need to be assessed, hence only the residential spaces need to be assessed against the residential criteria to demonstrate compliance with criterion 8 .
Where more than 5% of the floor area of the assessed building includes areas other than self-contained dwellings or rooms for residential purposes:
The calculation for the percentage of floor area that is 'non-residential' should only include occupied spaces (as defined in BREEAM issue Hea 01 Visual comfort).
|Hotel type - Sound insulation||Bedrooms in hotels must be considered acoustically sensitive rooms. Sound insulation (DnT,w) for partitions and floors between rooms and between rooms and corridors should be > 50dB.|
|Residential only - Acoustic testing|
Testing should be between habitable rooms on the ground floor and at higher storey levels, if applicable. Where there are not enough suitable separating walls or floors in a development to carry out the number of tests specified in the relevant national regulations or standards, all of the available suitable separating walls or floors must be tested.
Note: separating walls can be defined as those walls which separate dwellings.
|Residential only - Mixed use developments||For mixed use developments where commercial premises share a separating wall or floor with residential spaces, a SQA shall propose an appropriate baseline performance making reference to national or international guidance, or good practice.|
Residential only - Commercial space
|Where a commercial space is separated from a dwelling or room for residential purposes by a separating wall or floor, testing shall be carried out between the commercial space and dwelling, with the commercial space being used as the source room irrespective of the volume.|
|Residential only - Pre-completion testing|
No pre-completion testing is required where separating walls or floors only occur between non-habitable rooms, or non-habitable rooms and other spaces. In such cases, three credits can be awarded following an assessment by a SQA confirming that the constructions detailed would be capable of achieving the relevant performance requirements. No pre-completion testing is required where the dwellings are detached. In such cases, four credits can be awarded by default.
|Residential only - Measurement procedures||Additional information outlines the requirements for carrying out measurements and calculations to demonstrate compliance with this BREEAM issue. The appointed acoustician must confirm that the acoustic performance has been measured or calculated in accordance with these procedures. Where the acoustician has felt it necessary to deviate from these procedures, they must give justifiable reasons why they have done so.|
Where specific guidance on testing, measurement and calculation is not stated in the criteria tables above for the relevant building type, or within the relevant standard or guidance referenced, the following procedures can be followed by the acoustician when measuring or calculating the levels required to demonstrate compliance with this BREEAM issue.
Measurements of sound insulation (airborne and impact) should be made in accordance with the relevant part of the ISO 16283 series. For measurements of reverberation time, the relevant principles of ISO 354:2003 should be used and the guidance provided in ISO 16283-1:2014 should be followed in respect of the number of source and microphone positions, and decay measurements. For measurements of ambient noise, when no specific guidance is available, the following procedures should be used.
The above is intended as guidance for undertaking acoustic testing or measurements to demonstrate compliance with the performance requirements in BREEAM. If the acoustician has felt it necessary to deviate from the above procedures, they should provide a reason for doing so and confirm that the alternative procedures are adequate for demonstrating that the building meets the acoustic performance requirements.
When the country does not have legislation regarding frequency of testing, the following guidance below sets out the number of airborne or impact sound insulation tests to be conducted on each group or sub-group. A unit is either a flat or a house. Where units contain a single habitable room, i.e. bedsits, the number of tests required is halved.
The following guidance and examples on how to define groups and sub-groups is provided:
|Type of testing||Houses||Apartments|
|Number of tests|
|Airborne sound insulation test of separating walls between units||2||2|
|Airborne sound insulation test of separating floors between units||N/A||2|
|Impact sound insulation tests of separating floors between units||N/A||2|
If a development consists of three houses; one set of tests will be required:
If a development comprises 42 houses and 59 apartments; then five sets of tests between houses and 6 sets of tests between apartments will be required:
|Criteria||Interim design stage||Final Post-construction stage|
|All (non-residential type)|
Professional report or study and calculations from the acoustician.
Letter of appointment or other confirmation demonstrating when the acoustician was appointed.
The relevant section or clauses of the building specification or contract, or a formal letter from the project team regarding commitments.
Professional field report or study and calculations from the acoustician post-construction demonstrating compliance with the relevant credit criteria.
Evidence, such as a formal letter from the acoustician or their test report confirming that they meet BREEAM’s definition of a SQA.
Where remediation works have been carried out, a professional field report or study and calculations from the acoustician post-completion of the works demonstrating compliance with the credit requirements.
|All (residential buildings and residential institutions)|
Where pre-completion testing will be carried out, a letter from the developer confirming the intent to:
Copies of the sound insulation field test results or a letter of confirmation that the required sound insulation performance standards as detailed in the assessment criteria have been achieved AND
Evidence that the tests have been carried out by a compliant test body.
Noise assessments based on NR curves are often used by building services consultants to predict internal noise levels due to mechanical ventilation systems. However, the BREEAM requirement uses the indoor ambient noise level, LAeq,T which includes external noise transmitted via the façade as well as internal noise such as that from mechanical ventilation systems. In the absence of strong low frequency noise, LAeq,T can be estimated from the NR value using the following formula: LAeq,T≈ NR + 6 dB. Therefore, if the NR value is known, but not the sound pressure levels in the individual frequency bands, an estimate for the indoor ambient noise level LAeq,T can still be determined from the NR value for the building services noise. The LAeq,T for the external noise transmitted via the façade must then be combined with the LAeq,T for the building services.
BREEAM International New Construction 2016
Reference: SD233 – Issue: 2.0
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