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Hea 05 Acoustic performance

Number of credits available	Minimum standards
Building type dependent	No

Aim

To ensure the building's acoustic performance including sound insulation meet the appropriate standards for its purpose.

Assessment criteria

The following is required to demonstrate compliance:

Up to three credits for Education, Healthcare, Office and Law courts building types

The building meets the appropriate acoustic performance standards and testing requirements defined in the checklists and tables section which defines criteria for the acoustic principles of:
1. Sound insulation
2. Indoor ambient noise level
3. Reverberation times.

Up to three credits are available for Industrial, Retail, Prisons and ‘Other’ building types

Up to two credits

Where the building meets the acoustic performance standards and testing requirements detailed in Table 23 (see Checklists and tables) for all relevant functional areas.

Up to three credits

Where a suitably qualified acoustician (see relevant definitions) is appointed to define a bespoke set of performance requirements for all function areas in the building using the three acoustic principles defined in criterion 1, setting out the performance requirements for each and the testing regime required.

Up to four credits are available for Multi-residential and Other, Residential institutions building types

One, three or four credits are available for Multi-residential and Other, Residential institution buildings where the relevant criteria in the checklists and table section have been applied. Please also see CN3.

Checklists and tables

Table 19 BREEAM acoustic criteria for Education buildings

Education buildings (three credits)
First credit - Sound insulation
Criteria	Achieve the performance standards set out in Section 1 of Building bulletin 93: Acoustic design of schools: performance standards, February20151Building bulletin 93: Acoustic design of schools: performance standards, Department of Education, February 2015 (BB93) relating to airborne sound insulation between spaces and impact sound insulation of floors.
Testing requirement	A programme of pre-completion acoustic testing is carried out by a compliant test body in accordance with the BB93 requirements and the ANC Good Practice Guide, Acoustic testing of Schools2ANC Good Practice Guide, Acoustic Testing of Schools, version 1.2, July 2011.
Second credit - Internal indoor ambient noise levels
Criteria	Achieve the indoor ambient noise level standards set out within Section 1 of BB93for all room types. For lightweight roofs and roof glazing, calculations using laboratory data with ‘heavy’ rain noise excitation as defined in BS EN ISO 140-183BS EN ISO 140-18:2006 Acoustics. Measurement of sound insulation in buildings and of building elements are required (in accordance with the guidance in BB93) for teaching/learning spaces to demonstrate that the reverberant sound pressure level in these rooms are not more than 25 dB above the appropriate limits presented within Section 1 of BB93, table 1.
Testing requirement	Indoor ambient noise levels (excluding rain noise): A programme of acoustic measurements is carried out by a compliant test body in accordance with the ANC Good Practice Guide, Acoustic testing of Schools. Rain noise: installation of a specification compliant with the BB93criteria demonstrates compliance, reference is also made to the notes below.
Notes	For heavy weight roofs, or parts of the roof that are heavyweight, with a mass per unit area greater than 150kg/m² (including those with sedum planting) that do not have any glazing or rooflights, calculations are not required, as such the credit can be awarded on a default basis of compliance.
Third credit - Reverberation
Criteria	Acoustic environment (Control of reverberation, sound absorption and speech transmission index (STI)): Teaching and study spaces: achieve the requirements relating to reverberation time for teaching and study spaces set out within table 6 in Section 1 of BB93. Open plan teaching spaces: achieve the performance requirements relating to speech transmission index (STI) set out within Section 1.8 of BB93 . Corridor and stairwells: for those that give direct access to teaching and study spaces, achieve the performance requirements relating to sound absorption.
Testing requirement	Teaching and study spaces: A programme of acoustic measurements is carried out by a compliant test body in accordance with the ANC Good Practice Guide, Acoustic testing of Schools. Open plan teaching spaces: STI Measurements of the STI should be taken in at least one in ten typical student listening positions in the open plan spaces in accordance with the ANC Good Practice Guide, Acoustic testing of Schools. Corridors and stairwells: Installation of a specification compliant with the BB93 criteria demonstrates compliance. Where this refers to the use of Building Regulations, the country-specific Building Regulations or standards can be applied.

Table 20 BREEAM acoustic criteria for Healthcare buildings

Healthcare buildings (three credits)
First credit - Sound insulation
Criteria	Achieve the airborne sound insulation performance standards set out in Section 2 of HTM 08-01: Acoustics, 20134HTM 08-01: Acoustics, Health Technical Memorandum, Department of Health, 2013 determined according to the privacy requirements using both Table 3 and Table 4 from HTM 08-01: Acoustics. Impact noise is controlled at source and the weighted standardised impact sound pressure level (L’nT,w) does not exceed 65dB in noise-sensitive rooms, following the guidance in HTM 08-01: Acoustics. For assessments in Scotland, see also CN5.
Testing requirement	A programme of pre-completion acoustic testing is carried out by a compliant test body in accordance with the requirements of Section 7 of HTM 08-01: Acoustics. For assessments in Scotland, see also CN5.
Second credits - Internal indoor ambient noise levels
Criteria	The indoor ambient noise requirements for noise intrusion from external sources in Table 1 of HTM 08-01: Acoustics, 2013 are not exceeded. The values for internal noise from mechanical and electrical services in Table 2 of HTM 08-01: Acoustics are not exceeded. For assessments in Scotland, see also CN5.
Testing requirement	A programme of acoustic measurements is carried out by a compliant test body in accordance with the Section 7 of HTM 08-01: Acoustics. Rain noise: Installation of a specification compliant with the HTM 08-01: Acoustics criteria demonstrates compliance. For assessments in Scotland, see also CN5.
Third credit - Reverberation
Criteria	Acoustic environment (Control of reverberation, sound absorption and speech transmission index (STI)): Achieve the requirements relating to sound absorption set out in Section 2 of HTM 08-01: Acoustics. For assessments in Scotland, see also CN5.
Testing Requirement	A programme of acoustic measurements is carried out by a compliant test body in accordance with the Section 7 of HTM 08-01: Acoustics. For assessments in Scotland, see also CN5.

Table 21 BREEAM acoustic criteria for Office buildings

Office buildings (three credits)
First credit - Sound insulation
Criteria	The sound insulation between acoustically sensitive rooms and other occupied areas complies with the performance criteria given in Section 7 of BS 8233:20145BS 8233: Sound Insulation and noise reduction for buildings - Code of practice, 2014.
Testing requirement	A programme of pre-completion acoustic testing is carried out by a compliant test body in accordance with the acoustic testing and measurement procedures outlined in the Additional information section of this BREEAM issue.
Notes	If testing is to be carried out where the office is not yet furnished, then section 7.5 of BS 8233:2014 should be referred to when determining the performance criteria. Where the office is to be furnished at the time testing is carried out, then refer to section 7.7.6 of BS 8233:2014 for the relevant performance criteria.
Second credit - Internal indoor ambient noise levels
Criteria	Achieve indoor ambient noise levels that comply with the design ranges given in Section 7 of BS 8233:2014.
Testing requirement	A programme of acoustic measurements is carried out by a compliant test body in accordance with the acoustic testing and measurement procedures outlines in the Additional information section of this BREEAM issue.
Third credit - Reverberation
Criteria	Acoustic environment (control of reverberation, sound absorption and speech transmission index): Achieve the requirements relating to sound absorption and reverberation times, where applicable, set out in Section 7 of BS 8233:2014.
Testing Requirement	A programme of acoustic measurements is carried out by a compliant test body in accordance with the acoustic testing and measurement procedures outlined in the Additional information section of this BREEAM issue.

Table 22 BREEAM acoustic criteria for Law courts buildings

Law courts buildings (three credits)
First credit - Sound insulation
Criteria	The sound insulation between acoustically sensitive rooms and other occupied areas complies with the performance targets given in Section 28 of Court Service Design Guide (CSDG), HMCS, 20106Court Service Design Guide (CSDG), Her Majesty's Court Service (HMCS), 2010. For assessments in Scotland, see also CN5.
Testing requirement	A programme of pre-completion acoustic testing is carried out by a compliant test body in accordance with the requirements of Section 28 of the CSDG and ‘Calculation Procedures’ where applicable. For assessments in Scotland, see also CN5.
Second credits - Internal indoor ambient noise levels
Criteria	Achieve indoor ambient noise levels that comply with the requirements of Section 28 of the CSDG. For assessments in Scotland, see also CN5.
Testing requirement	A programme of acoustic measurements is carried out by a compliant test body in accordance with Section 28 of the CSDG. For assessments in Scotland, see also CN5.
Third credit - Reverberation
Criteria	Acoustic environment (Control of reverberation, sound absorption and speech transmission index): Achieve the requirements relating to sound absorption and reverberation times, where applicable, set out in Section 28 of the CSDG. For assessments in Scotland, see also CN5.
Testing requirement	A programme of acoustic measurements is carried out by a compliant test body in accordance with Section 28 of the CSDG and ‘Calculation Procedures’ where applicable. For assessments in Scotland, see also CN5.

Table 23 BREEAM acoustic criteria for Industrial, Retail, Prisons and Other building types

Industrial, Retail, Prisons and Other building types (two credits)
First credit – Sound insulation and internal indoor ambient noise levels
Room function	All room functions
Criteria	Internal indoor ambient noise levels: Indoor ambient noise levels comply with the design ranges given in BS 8233: 2014 unless otherwise stated below. Where the room types below are present, the appropriate criteria for ambient noise levels, sound insulation and acoustic privacy must also be achieved.
Testing requirement	Internal indoor ambient noise levels: A programme of pre-completion acoustic testing is carried out by a compliant test body in accordance with the acoustic testing and measurement procedures outlined in the Additional information section of this BREEAM issue.
Room function	Educational space (teaching and lecture spaces)
Criteria	Internal indoor ambient noise levels: Achieve the indoor ambient noise level standards set out within Section 1 of BB93 for all teaching and lecture theatre room types. See also the criteria below for acoustically sensitive rooms and apply if relevant.
Testing requirement	Internal indoor ambient noise levels: A programme of acoustic measurements is carried out by a compliant test body in accordance with the ANC Good Practice Guide, Acoustic testing of Schools. Rain noise: Installation of a specification compliant with the BB93 criteria demonstrates compliance; reference is also made to the Notes section in Table 19 .
Notes	For heavy weight roofs, or parts of the roof that are heavyweight, with a mass per unit area greater than 150kg/m² (including those with sedum planting) that do not have any glazing/rooflights, calculations are not required. As such, the credit can be awarded on a default basis of compliance.
Room function	Medical treatment rooms
Criteria	Sound insulation: Achieve the airborne and impact sound insulation criteria in Health Technical Memorandum HTM 08-01. For assessments in Scotland, see also CN5.
Testing requirement	Sound insulation: A programme of pre-completion acoustic testing is carried out by a compliant test body in accordance with the requirements of Section 7 of HTM 08-01: Acoustics.
Room function	Acoustically sensitive rooms
Criteria	Sound insulation: The sound insulation between acoustically sensitive rooms and other occupied areas complies with the example matrix relating to internal sound insulation within Section 7.5 of BS 8233:2014 which takes into consideration the likely level of activity noise, the degree of privacy required and the sensitivity of the adjacent space. It may be considered appropriate to adapt the levels of sound insulation presented within the table according to a specific building’s use and any modification to the criteria should be justified by an SQA. Examples of rooms with a 'confidential' privacy requirement may include human resources meeting rooms, or rooms where private conversations may be taking place, however their 'activity noise' is likely to be only 'typical' and then the level of sound insulation would be determined based on the sensitivity of the receiving space. Factory spaces are likely to be considered less sensitive as a receiving space than an adjacent office area, however the activity noise level may be anticipated to be higher.
Testing requirement	Sound insulation: A programme of pre-completion acoustic testing is carried out by a compliant test body in accordance with the acoustic testing and measurement procedures in the Hea 05 Acoustic performance section.
Notes	See Hea 05 Acoustic performance. 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.
Second credit – Reverberation
Room function	Rooms/areas used for speech or performance, including public speaking
Criteria	Achieve reverberation times compliant with Section 1 of BB93. In addition, or alternatively, if relevant to the assessed building; classrooms, seminar rooms and lecture theatres achieve reverberation times compliant with section 1 of BB93.
Testing requirement	Reverberation times within teaching and study spaces: A programme of acoustic measurements is carried out by a compliant test body to achieve the required performance standards set out in table 6 in section 1 of BB93. Measurements should be carried out in accordance with the ANC Good Practice Guide, Acoustic testing of Schools. Open Plan teaching spaces: STI Measurements of the STI should be taken in at least one in ten typical student listening positions in the open plan spaces in accordance with the ANC Good Practice Guide, Acoustic testing of Schools. Corridors and stairwells: installation of a specification compliant with the BB93criteria demonstrates compliance. Reference is also made to the Notes below.
Notes	Where the reverberation time required by the relevant standard is not appropriate for the type of space/building assessed, the acoustician must confirm why this is the case. In addition the acoustician must set alternative appropriate reverberation times and provide these to demonstrate compliance.

Table 24 BREEAM acoustic criteria for Multi-residential buildings and 'Other residential' institutions

Multi-residential and 'Other residential' buildings (four credits)
Room function	Individual bedrooms and self-contained dwellings
Criteria	One credit Airborne sound insulation values are at least 3dB higher and impact sound insulation values are at least 3dB lower than the performance standards in the relevant Building Regulations or Standards. Three credits Airborne sound insulation values are at least 5dB higher and impact sound insulation values are at least 5dB lower than the performance standards in the relevant Building Regulations or Standards. Four credits Airborne sound insulation values are at least 8dB higher and impact sound insulation values are at least 8dB lower than the performance standards in the relevant Building Regulations or Standards.
Testing requirement	A programme of pre-completion testing is carried out by a compliant test body based on the normal programme of testing described in the relevant Building Regulations or Standards for every group or sub-group of dwellings (houses, flats or rooms for residential purposes) this must demonstrate that the performance standards detailed within this table are achieved. OR Use of constructions for all relevant building elements have been registered with and assessed and approved by Robust Details Limited (RDL) and found to achieve the performance standards required for the number of credits sought (see additional information section for further information on Robust Details).
Notes	Testing should be between habitable rooms on the ground floor and at higher storey levels if applicable. Where there are insufficient suitable separating walls or floors in a development to carry out the number of tests specified in the appropriate Building Regulations or Standards, all of the available suitable separating walls or floors must be tested. See also CN5 and CN3.

Compliance notes

Ref	Terms	Description
Shell and core
CN1	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 – BREEAM UK New Construction and Shell and Core Project Assessments for a more detailed description of the above shell and core assessment options.
CN1.1	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 suitably qualified acoustician (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 the developer's works will enable a future tenant utilising a typical fit-out and specification to meet the levels required to demonstrate compliance with the BREEAM criteria.
Simple buildings
CN2	Applicable assessment criteria	This issue is not applicable.
General
CN3	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.
CN3.1	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 re-tested 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 criteria (see Hea 05 Acoustic performance and Hea 05 Acoustic performance section), and include the relevant pass/fail criteria.
CN3.2	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, for example in small healthcare facilities. Where this is the case, clear reasoning must be provided by the compliant test body prior to awarding the credit(s).
Building type specific
CN4	Education BB93, February 2015 See Table 19	The Acoustic Performance Standard for the Priority Schools Building Programme (APS), June 2013, referenced in previous versions of the manual has been replaced by the ‘Building Bulletin 93: Acoustic design of schools: performance standards’ published by the Department of Education in February 2015.
CN4.1	Multi-residential or Other, Residential institutions Rooms not covered by residential criteria	Multi-residential and other 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 Table 24 . Where more than 5% of the floor area of the assessed building includes areas other than self-contained dwellings or rooms for residential purposes: If awarding 1 credit, only the self-contained dwellings and/or rooms for residential purposes need to be assessed to demonstrate compliance. If awarding 3 or 4 credits the ‘non-residential’ areas must meet the relevant criteria for their function, as set out in Table 23 for ‘other buildings’ and the self-contained dwellings or rooms for residential purposes need to be assessed to demonstrate compliance. 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) covered by the Other buildings criteria.
Country specific
CN5	Country specific guidance	The following Standards or Building Regulations etc. are relevant for the assessment of the issue: England For Multi-residential assessments, where the criteria refer to the performance standards in Building Regulations, in England, this is referring to Approved Document E 2003 edition, with amendments 2004 and 2010 – Resistance to the passage of sound. Northern Ireland For Multi-residential assessments, where the criteria refer to the performance standards in Building Regulations, in Northern Ireland, this is referring to - DOE Technical Booklet G - Sound 2012 Scotland For Healthcare buildings, where the criteria refer to the use of HTM08-01, assessments in Scotland should use SHTM08-017SHTM 08-01, Scottish Health Technical Memorandum 08-01: Specialist Acoustics, NHS National Services Scotland, May 2011. For Law Courts buildings, where the criteria refer to the use of Section 28 of Court Service Design Guide (CSDG), HMCS, 2010-assessments in Scotland should refer to ETS-01 Courtroom technology and spatial requirements design guide 20118ETS-01 Courtroom technology and spatial requirements, design guide, Scottish Court Service, 2011 and ETS-03 Estates technical standard environmental performance, design guide 20119ETS-03 Estates technical standard environmental performance, design guide, Scottish Court Service, 2011. For Multi-residential assessments, where the criteria refer to the performance standards in Building Regulations, in Scotland, this is referring to Approved Document E 2003 edition, with amendments 2004 and 2010 – Resistance to the passage of sound. Wales For Multi-residential assessments, where the criteria refer to the performance standards in Building Regulations, in Wales, this is referring to Approved Document E 2003 edition, with amendments 2004 and 2010 – Resistance to the passage of sound.

Methodology

Testing, measurement and calculation procedures

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/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 BS EN ISO 140 series, or the successor to these standards. For measurements of reverberation time, the relevant principles of BS EN ISO 354:2003 should be used and the guidance provided in BS EN ISO 140-7:1998 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:

Noise from both internal sources (e.g. mechanical ventilation systems, plant noise, noise-making systems) and external sources (e.g. traffic noise transmitted via the building façade) should be included, and, where windows are openable as part of the ventilation strategy, these should be assumed to be open for the purposes of calculations and open for measurements. If openable windows are not part of the background/permanent ventilation strategy, then these should be assumed to be closed for the purposes of calculation and closed for measurements.
Noise from occupants and office equipment (e.g. computers) should not be included in the measurements.
Unless otherwise stated in the referenced document, a rate of testing of at least one in ten rooms/spaces of each performance level shall be subject to on-site performance testing.
Measurements should be made in at least four rooms in which noise levels can be expected to be greatest either because they are on the noisiest façade or because they are on a naturally ventilated façade.
Where different ventilation strategies are used, measurements should be conducted in rooms utilising each strategy. Otherwise, measurements should be made in rooms on the noisiest façade.
T in L_Aeq,T is taken as the duration of the normal working day (typically 8 hours between 09.00 and 17.00).
Measurements need not be made over a period of 8 hours if a shorter measurement period can be used. In this case, measurements should be made when external noise levels are representative of normal conditions throughout the day.
Measurement periods less than 30 minutes may give representative values for indoor ambient noise levels and may be utilised where this is the case. However measurement periods shorter than 5 minutes should not be used.
Measurements should be taken in a minimum of three locations in rooms at a height of 1.2m above the floor level and at least 1m away from any surface.
Where relevant, measurement of airborne sound insulation between teaching spaces should be conducted between one in four pairs of adjacent rooms (or teaching spaces) of each room type or performance requirement category and construction type.
Where relevant, measurement of impact sound pressure level should be conducted in one in four teaching spaces (separated from rooms above) of each room type or performance requirement category and construction type.
The measured level of ambient noise should be used to determine compliance with the criteria for acoustically sensitive rooms. If at the time of acoustic commissioning it is not possible to measure ambient noise levels in the absence of construction or other extraneous noise sources that will not be present when the building is complete, then, for mechanical services the lower level of 35 dB, L_Aeq or the lowest design limit for the acoustically sensitive space should be used.

The above is intended as guidance for undertaking acoustic testing or measurement 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.

Evidence

Criteria	Interim design stage	Final post construction stage
All	One or more of the appropriate evidence types listed in The BREEAM evidential requirements section can be used to demonstrate compliance with these criteria.
4	Multi-residential specific Where Robust Details are to be used, the following must be provided: Design team confirmation that Robust Details chosen will achieve the required performance standards for sound insulation. Purchase Statement from RDL which confirms that the relevant plots are registered with RDL.	Completed Robust Details Ltd Compliance Certificate signed by the developer for all relevant constructions relating to the plots being assessed.

Criteria

Interim design stage

Final post construction stage

All

One or more of the appropriate evidence types listed in The BREEAM evidential requirements section can be used to demonstrate compliance with these criteria.

Multi-residential specific
Where Robust Details are to be used, the following must be provided:

Design team confirmation that Robust Details chosen will achieve the required performance standards for sound insulation.
Purchase Statement from RDL which confirms that the relevant plots are registered with RDL.

Completed Robust Details Ltd Compliance Certificate signed by the developer for all relevant constructions relating to the plots being assessed.

Additional information

Relevant definitions

Acoustically sensitive rooms

Where the term ‘acoustically sensitive rooms’ is referenced in this BREEAM issue, it refers to);

Cellular offices
Meeting/interview/consulting/treatment rooms.
Court buildings: Witness/consultation rooms and Judges'/magistrates' chambers and jury retiring rooms.
Prison buildings: Care/listener suites, Official visit rooms, 'Closed visits' rooms.
Educational buildings/spaces: rooms for teaching and learning i.e. classrooms, lecture theatres.
Rooms used for public speaking or seminars.
Any other room/space the design team or client deems to be acoustically sensitive for the purposes of privacy.

Compliant test body

A Compliant Test Body is defined as :

Organisations having United Kingdom Accreditation Scheme (UKAS) accreditation to the appropriate scope (for e.g. to BS EN ISO/IEC 17025), or who are accredited by a member of the International Accreditation Forum (IAF - www.iaf.nu) to the appropriate scope OR
Organisations or individuals registered with the Association of Noise Consultants (ANC) Registration Scheme OR
Companies or individuals that have been declared competent by an organisation who can provide evidence that they follow the relevant principles of BS EN ISO/IEC 17024 (Conformity assessment - General requirements for bodies operating certification of persons)10ISO/IEC 17024:2003 Conformity assessment - General requirements for bodies operating certification of persons in relation to BREEAM requirements.

Groups and sub-groups

As defined in the Building Regulations for England and Wales Approved Document E: Resistance to the Passage of sound, section 1 (paragraphs 1.11 – 1.17). For example, flats and study bedrooms are usually considered as two separate groups, and if there are significant differences in construction type then the groups will need to be broken down into sub groups. In addition to this, where there are steps or staggers greater than 300mm between dwellings, dwellings without steps/staggers should be treated as a different sub-group to those with step/staggers. This is because the presence of steps/staggers is likely to improve performance.

Habitable rooms

For the purpose of this issue, habitable rooms include any room where individuals will sit or lie down and require a reasonably quiet environmental to concentrate or rest. Such rooms are bedrooms, living rooms, dining rooms, studies as well as kitchen-dining and kitchen-living rooms.

Material change of use

This is where there is a change in the purpose for which or the circumstance in which a building is used e.g. where a building has been converted from a non-dwelling (office, school, church etc.) to a dwelling.

Multiple occupancy offices

Office space that is not cellular in nature, i.e. it is open plan, and designed to accommodate more than two desk spaces/workstations.

Non-habitable rooms

For the purpose of this issue, non-habitable rooms include any room that is not considered a habitable room (as defined above), it includes rooms such as kitchens, bathrooms, toilets, hallways, garages and laundry rooms.

Occupied spaces

Refer to BREEAM issue Hea 01 and note that for BREEAM issue Hea 05 there is a specific, unrelated, definition of 'unoccupied' with reference to acoustic testing and measurement, see Compliance notes for details.

Robust Details

Robust Details (RDs) are construction solutions that provide an alternative to pre-completion sound insulation testing as a method of complying with Requirements E1 of Approved Document E (2003 edition) of the Building Regulations (England and Wales), DOE Technical Booklet G - Sound 2012 (Northern Ireland) and Technical Handbook Section 5 - Noise, 2013 (Scotland). The relevant plots on a development must be registered with RDL and built in accordance with the RD specification. To give a reasonable level of assurance that these details will achieve the required minimum standards, RDL carry out random inspections during construction and random sound insulation tests after construction. A Robust Detail is deemed to be approved for BREEAM (Multi-residential building) credits only when it achieves a specified performance level as assessed by RDL. Robust Details can only be used in relation to assessment for new build dwellings and cannot be used to assess the performance of construction details in rooms for residential purposes or material change of use.

Room for residential purposes

This is defined within the Building Regulations for England and Wales Approved Document E as a room, or a suite of rooms which is not a dwelling (house or a flat) and which is used by one or more persons to live and sleep. It includes a room in a hostel, hotel, a boarding house, a hall of residence or a residential home, whether or not the room is separated from or arranged in a cluster group with other rooms, but does not include a room in hospital, or other similar establishment, used for patient accommodation.

Specified performance level

Robust Details are approved for credits under the Code for Sustainable Homes (CSH), where the specified performance levels set out below are met. Construction types that meet these levels are listed on the Robust Details website www.robustdetails.com on the CSH page. Where assessing self-contained dwellings in multi-residential buildings that are not defined as material change of use or rooms for residential purposes, Robust Details that meet the specified performance level as set out below can also comply with the credit criteria for self-contained units in Multi-residential buildings and reference must be made to the CSH page on the Robust Details website:

Mature Robust Details (published for over 12 months and at least 100 test results) – regular assessment based on the 90th percentile of results from the last 100 site tests
Low use Robust Detail (published for over 12 months but fewer than 100 test results) – initial assessment based on the first 30 tests needed to qualify for the Robust Details scheme and the site tests available, and reviewed regularly as new test results become available, until it becomes a mature Robust Detail or is rejected.
New Robust Detail (published for less than 12 months and fewer than 100 test results) – initial assessment based on the first 30 tests needed to qualify for the Robust Details scheme, and reviewed regularly as new test results become available, until it becomes a mature Robust Detail or is rejected.

It should be noted that not all RDs will necessarily achieve the performance levels required to achieve multi-residential credits. If in doubt, please check the list of currently approved details with RDL directly at www.robustdetails.com.

Suitably qualified acoustician (SQA)

An individual achieving all the following items can be considered to be 'suitably qualified' for the purposes of a BREEAM assessment:

Holds a degree, PhD or equivalent qualification in acoustics/sound testing.
Has a minimum of three years relevant experience (within the last five years). Such experience must clearly demonstrate a practical understanding of factors affecting acoustics in relation to construction and the built environment; including, acting in an advisory capacity to provide recommendations for suitable acoustic performance levels and mitigation measures.
An individual who holds a recognised acoustic qualification and membership of an appropriate professional body. The primary professional body for acoustics in the UK is the Institute of Acoustics.

Where a suitably qualified acoustician is verifying the acoustic measurements/calculations carried out by another acoustician who does not meet the SQA requirements, they must, as a minimum, have read and reviewed the report and confirm in writing that they have found it to:

Represent sound industry practice
Be appropriate given the building being assessed and scope of works proposed
Avoid invalid, biased and exaggerated recommendations.

Additionally, written confirmation from the third party verifier that they comply with the definition of a Suitably Qualified Acoustician is required.

Single occupancy offices

Cellular office space designed to accommodate one or two desk spaces/workstations (typically no greater than 10m²).

Unoccupied spaces

Where the term ‘unoccupied space’ is referenced in this BREEAM issue it refers to the nature of the space for the purpose of carrying acoustic calculations or measurements i.e. such measurements must be carried out when the space is unoccupied and therefore devoid of sources of noise.

Weighted standardized level differences (DnT,w)

HTM 08-01 defines this as the ‘unit for rating airborne sound insulation on-site’.

Weighted standardised impact sound pressure level (L'nT,w)

HTM 08-01 defines this as the ‘unit for rating impact airborne sound insulation on-site’.

Other information

Noise rating (NR) curves

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, L_Aeq,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, L_Aeq,T can be estimated from the NR value using the following formula: L_Aeq,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 L_Aeq,T can still be determined from the NR value for the building services noise. The L_Aeq,T for the external noise transmitted via the façade must then be combined with the L_Aeq,T for the building services.