Matthewsgreen Primary School and Community Facility Acoustics - Stage 3 Report

For: Faithful + Gould

Job No: 1014076

Doc Ref: 1014076-RPT-AS-001

Latest Revision: C

Date: 17/02/2017

Cundall Johnston and Partners LLP One Carter Lane London EC4V 5ER Tel +44 (0)20 7438 1600 www.cundall.com

160 Matthewsgreen Primary School and Community Facility Stage 3 Report | March 2017

Project Name: Matthewsgreen Primary School and Community Facility

Client: Faithful + Gould

Report Title: Acoustics - Stage 3 Report

Job Number: 1014076

Document Revision History

Revision Issue Date Purpose of issue / description of revision Ref

- 03/02/2017 Draft issue for comment

A 10/02/2017 Updated following review

B 16/02/2017 Updated following review

C 17/02/2017 Updated following review

Document Validation (latest issue)

17/02/2017 17/02/2017 17/02/2017 X X X Principal author Checked by Verified by

Signed by: Lees, Alex Signed by: Hyden, Matthew Signed by: Turner, Rob

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Executive Summary

This report outlines the acoustic design strategy for the proposed teaching block at Matthewsgreen Primary School and Community Facility, Wokingham.

The purpose of this report is to stipulate acoustic performance requirements for the development which are in line with current regulations and codes of practice, in particular Building Bulletin 93 ‘Acoustic design of schools – performance standards’ (BB93). Acoustics-related planning conditions are also addressed within this report.

Acoustic performance criteria are set out on the basis of relevant guidance and standards in relation to:

 Indoor ambient noise levels;  Airborne and impact sound insulation;  Reverberation time; and  Services plant noise limits. With regards to achieving appropriate internal ambient noise levels, a hybrid ventilation strategy has been developed for the building, based on noise modelling of nearby roads. A short-term noise survey was also carried out at the site in order to provide a reference point for the modelled noise levels. The noise survey confirmed the assumption that road traffic noise will be dominant at the school site. It is proposed that classrooms on the northern façade shall be provided with Enhanced Natural Ventilation Units (ENVUs), whereas higher noise levels on the southern façade will necessitate a mechanical ventilation system. With regard to internal sound insulation, performance requirements for the internal partitions and floors have been provided to meet the minimum criteria set out in BB93, along with examples of suitable constructions. Details and guidance have also been provided for internal doors, glazing and the proposed moveable partition.

Regarding the reverberation times within the proposed building, advice on acoustic absorption is given in order to achieve the target reverberation time in the key spaces. This includes indicative acoustic absorption coverage areas required to achieve the criteria.

A noise limit for any new items of external plant have been set to prevent increasing the existing background noise level. This limit is summarised in the table below and is to be applied at 1m from the façade of the nearest noise-sensitive receptor.

School and community centre Existing background noise Plant noise level limit dB operation period (hrs) level dB LA90 LAeq, T

08:00 to 22:00 hours 55 45 Table 1 – Plant noise limits

It is understood that external building services plant is only likely to operate whilst the school and community centre are open i.e. 08:00 to 22:00 hours.

Further coordination works will be required during the next stage to assess the proposed construction against the required performance and advise on acoustically critical detailing such as junction and penetration details.

This report and marked-up acoustic strategy drawings are based upon Atkins architectural drawings dated 27 January 2017. Strategy drawings will need to be updated to match architectural general arrangement drawings as the design progresses beyond Stage 3.

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Contents

Introduction ...... 1

1.1 Brief ...... 1

1.2 Design Standards ...... 1

Acoustic design criteria ...... 2 2.1 Planning conditions ...... 2 2.2 Building Bulletin 93 ...... 2

Baseline noise conditions ...... 4 Acoustic design advice ...... 5 4.1 Building envelope ...... 5 4.2 Ventilation strategy ...... 5 4.3 Dividing floors ...... 5 4.4 Internal partitions ...... 5 4.5 Internal glazing ...... 6 4.6 Doorsets ...... 7 4.7 Reverberation control ...... 7

M&E Acoustics ...... 9 5.1 External plant noise emission ...... 9 5.2 Plant isolation ...... 9 5.3 General advice ...... 9

Appendix A – Planning Conditions ...... 11 Appendix B – Acoustic strategy drawings ...... 12 Appendix C - Alternative performance standards ...... 15 Appendix D – Background noise level data ...... 16

© This report is the copyright of Cundall Johnston & Partners LLP. The report is for the sole and confidential use of Faithful + Gould. It must not be reproduced whole or in part without the express written authorisation of Cundall Johnston & Partners LLP. Parties other than those specifically named in this disclaimer must not rely upon this report. Any third party relying on this report does so at their own risk. Cundall accepts no duty or responsibility whatsoever (including in negligence) to any such third party.

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Introduction

1.1 Brief

This report sets out the acoustic strategies for the proposed Matthewsgreen Primary School and Community Facility. The acoustic strategy highlights the design solutions that could be employed, whilst delivering cost- effective and serviceable acoustic solutions to facilitate an excellent teaching, learning and working environment for the School.

All advice included in this report should be read in conjunction with architectural, structural, mechanical and any other relevant design requirements. Any discrepancies should be communicated to the Acoustic Consultant.

1.2 Design Standards

In England and Wales, all new schools/school buildings are controlled under the Building Regulations Requirement (E4) of Approved Document Part E (ADE) ‘Resistance to the Passage of Sound’. The Building Regulations state that the way of satisfying Requirement E4 is to demonstrate that all the performance standards detailed in Section 1 of ‘Building Bulletin 93 – Acoustic Design of Schools’ have been met.

The acoustic strategy detailed in this report is provided in aim to fully comply with the criteria set out within:

 Building Bulletin 93 ‘Acoustic Design of Schools: Performance Standards’ (v17 February 2015);  Local Planning Authority requirements. The minimum acoustic requirements outlined in BB93 are mandatory to all new teaching and learning spaces within the proposed development. Although recommendations are given for administration and ancillary spaces, the performance standards for these areas are for guidance purposes only.

This report also takes into account guidance from the following additional publications:

 BS 4142:2014 – Methods for rating and assessing industrial and commercial sound; and  CIBSE Guide B – Heating, ventilating, air conditioning and refrigeration. Where the design of the school deviates from the BB93 criteria, alternative performance standards must be agreed with the School and Building Control.

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Acoustic design criteria Upper limit for the Guideline limit for indoor ambient noise cumulative noise Room type level from mechanical This Chapter outlines the acoustic performance criteria that are required to be achieved by the design of the (dB LAeq,30mins) * services, NR Matthewsgreen school. Primary / Reception / Nursery classroom, Main Hall, Studio, Multi-purpose Hall, Group Room, SEN 35 29 Resource 2.1 Planning conditions Teaching space for special hearing and 30 24 As part of the planning application for the wider development, several conditions are attached specifically to communication needs (specific SEN rooms) Matthewsgreen School. Noise related conditions relevant to this report are summarised below and Circulation space not intended for teaching 45 39 reproduced in Appendix A to this report. ICT Suite, Food/Sci/D&T, Library, Meeting, Office**, 40 34 Staff room**, Resource / Breakout Area  Condition 11 – Development briefs This condition appears to relate to the wider development as a whole and as such is not addressed Toilet**, Kitchen**, Hygiene** 50 44 within this report. * Values are specified in terms of dB LAeq, 30mins, which is the average noise level measured over a 30 minute period. **Criteria for ancillary spaces are for guidance only.  Condition 51 – Proposed Development – Protection from external noise Table 2 - Indoor ambient noise level criteria

Due to the constraints of the school site (being sandwiched between two major roads) it is unlikely that For rooms ventilated using natural or mixed mode / hybrid systems, IANLs up to 5 dBA above the values these criteria can feasibly be met without implementing extensive mitigation measures e.g. noise required for the associated space are permitted for noise break-in, i.e. for a standard classroom, the internal bunds. IANL would be ≤ 40 dBA, as opposed to ≤ 35 dBA.  Condition 52 – Noise from services associated with new buildings Noise from any new items of plant associated with the proposed development should be designed to During the summertime, natural or hybrid ventilation under control of teachers to prevent overheating during the criteria set out later in this report, when assessed at 1m from the façade of the nearest noise the hottest 200 hours of the year should be designed such that the indoor ambient noise level does not sensitive property. exceed 55 dB LAeq inside any spaces intended for student use.  Condition 53 – Submission prior to installation on a building The IANL excludes contributions from teaching activities (including noise from staff/students and This condition shall be addressed at a later design stage once plant selections have been finalised. playgrounds), equipment used in the space (such as computer equipment, etc.) and rain noise.  Condition 54 – School – Protection from external noise 2.2.2 Discrete noise events The building envelope design advice is provided in Section 4.1 of this report which addresses this condition. In order to protect students from regular discrete noise events, e.g. aircraft or trains, indoor ambient noise levels should not exceed 60 dB LA1,30mins. BB93 states that this is achieved by default for spaces with IANLs up 2.2 Building Bulletin 93 to 40 dB LAeq,30min, but requires assessment in spaces with higher IANL limits, e.g. 45 and 50 dB.

The acoustic design strategy is based on achieving the minimum requirements as set out within BB93 which 2.2.3 Rain impact noise sets out the acoustic requirements for schools, as follows: Although rain noise is excluded from the general IANL criteria, it is recommended that roofs and roof glazing 2.2.1 Internal ambient noise levels are designed to provide suitable control of rain noise reverberant sound pressure level in a space, such that during ‘heavy’ rain fall, the IANLs should not be more than 25 dB above the appropriate IANL specified in BB93 stipulates maximum indoor ambient noise level (IANL) criteria for all teaching and student spaces based Table 2. on the use of each space. Criteria relevant to Matthewsgreen School are reproduced in Table 2. The external building fabric and the ventilation strategy should provide sufficient sound reduction such that IANL criteria are 2.2.4 Airborne sound insulation maintained. The minimum airborne sound insulation performance of internal partitions and floors between adjacent Guideline limits are also provided for mechanical services noise, which are secondary to the limits for ambient teaching spaces is dictated by the activity noise level in the source room and the noise tolerance of the noise (LAeq,T) which should be achieved in the presence of both mechanical and environmental noise break-in. receiving room.

The on-site performance standards for airborne sound insulation between spaces are provided in terms of minimum BB93 Weighted Standardised Level Difference DnT,w. The sound insulation performance required by BB93 which are relevant to the proposed school are detailed in Table 3 and Table 4.

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Activity noise in source room Mid frequency reverberation time, Tmf Space Minimum DnT,w (seconds) Low Average High Very High

Noise High N/A 35 45 50 Classrooms ≤ 0.6 tolerance in Medium 40 45 50 55 receiving room Low 45 50 55 55 Main Hall, Studio*, Multi-Purpose Room, Table 3 – BB93 new build performance standards for airborne sound insulation between spaces 0.8 – 1.2 Community Hall BB93 also specifies airborne sound insulation requirements for the corridor wall between occupied spaces and circulation spaces, where a corridor door and/or ventilators are to be incorporated. The following performance criteria are applicable for the proposed design of Matthewsgreen School. T ≤ 0.4 averaged from 125 Hz to 4kHz octave band centre frequencies Minimum Minimum SEN Minimum and composite Rw composite Rw of Minimum dB Rw Dn,e,w -10 lg(N) Room type of wall and wall, glazing T ≤ 0.6 s in every octave for doorset (dB) for N ventilators glazing with no and ventilator band in this range. (dB) ventilator (dB) (dB) Library ≤ 1.0 Specific SEN rooms, 45 38 35 37 Group Area Multi-purpose ≤ 1.2 Hall (open plan resource / breakout area)

All other spaces used for teaching 40 33 30 32 Meeting room ≤ 0.8 or learning Table 4 - BB93 performance standards for airborne sound insulation between occupied spaces and circulation spaces

2.2.5 Impact sound transmission Staff Room**, Offices** ≤ 1.0 BB93 sets out the performance standards for impact sound transmission of floors. Values are specified in terms of maximum Weighted Standardised Impact Sound Pressure Level (L’nT,w) with lower values being more stringent.

*It is assumed that the Studio is a multi-purpose space for drama / occasional music performances, etc. For most general teaching spaces, a maximum impact sound pressure level of 60 dB L’nT,w is required, **Acoustic absorption in ancillary / community spaces are guidance values only and are not a requirement of building regulations. reducing to 55 dB L’nT,w for more noise sensitive spaces, such as teaching spaces intended specifically for students with special hearing or communication needs. Table 5 - Reverberation time criteria Reverberation control in corridors, entrance halls and stairways 2.2.6 Reverberation control The objective is to absorb sound in corridors, entrance halls and stairwells to reduce the level of transmission For occupied spaces into teaching spaces. BB93 sets out maximum reverberation times for different teaching and learning areas, these are provided on The BB93 requirement is to provide sound absorption coverage as calculated in accordance with ADE, the mark ups in Appendix B. The reverberation time criteria are for rooms that are finished, furnished for Section 7. This section of the ADE describes two calculation methods, A and B, for controlling reverberation in normal use, but unoccupied. the common internal parts of domestic buildings. One of these methods should be used to determine the amount of absorption required. The reverberation time for standard classrooms is quoted in terms of mid-frequency reverberation time (Tmf) which is the arithmetic average of the reverberation times in the 500 Hz, 1 kHz and 2 kHz octave bands. It should be noted that corridors and stairwells that do not give direct access to teaching spaces are not covered by this requirement.

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Baseline noise conditions

As detailed in the previous Stage 2 report, Cundall carried out a noise modelling exercise in order to predict potential levels of noise incident upon the school, due to the proposed North Distributor Road (NDR) situated at the southern site boundary. In addition, the A329(M) to the north was included in the model to predict noise levels at the north façade of the school.

It was found that once the NDR is fully constructed and operational, noise emissions from this road and the A329(M) to the north will be dominant across the site, and as such the acoustic design of the school is based upon the calculated noise impact from these sources. Other less significant noise sources include the Toutley Depot to the northeast and overflying aircraft travelling to and from Heathrow.

Noise levels were predicted with a noise model based upon future (2026) peak-hour traffic flow information supplied by WSP, in line with the previous Environmental Impact Assessment carried out for the wider development. The noise modelling process is described in more detail in the 1014076-RPT-AS-001 Acoustics Stage 2 Report.

Predicted free-field noise levels at the southern and northern façades of the proposed building are provided in the table below. A 2 dB margin has been included to account for uncertainties in the noise modelling process.

Predicted noise levels in Façade Floor dBA

Ground 59 North 1st 60 Ground 63 South 1st 63 Table 6 - Predicted free-field noise levels at the southern and northern façades

A short-term noise survey was also carried out at the site in order to provide a reference point for the modelled noise levels, details of which can be provided upon request. The noise survey confirmed the assumption that road traffic noise will be dominant at the school site. However, as the school was assessed against future traffic flows in 2026, the results of the noise survey were not used directly to inform the acoustic design of the school.

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Acoustic design advice

Most onerous School Worst case Minimum This Chapter provides practical acoustic design advice to achieve the on-site acoustic performance Room BB93 IANL building predicted façade Dn,e,w -10 lg N for requirements set out for Mathewsgreen School (as detailed in Chapter 2). type criterion façade noise level (dBA) ENVU (dB) (dB LAeq,30mins)

4.1 Building envelope All spaces For the vast majority of traditionally-built façades, the weakest elements of the external elevation are the used for North 60 40 29 glazing and any ventilation openings. Normally, the specification of these elements will be the primary factor in teaching determining the internal ambient noise level within noise sensitive rooms due to noise ingress from outside. or learning The minimum façade sound reduction requirements below are based on the ‘worst case’ noise modelling All results presented in Chapter 3. Minimum acoustic requirements are dependent on whether ventilation is spaces used for provided by mechanical or natural means. South 63 35 37 teaching or Minimum learning Worst case BB93 IANL required Table 8 - Minimum ENVU sound insulation performance requirements School building predicted Room type criterion glazing sound façade façade noise In order to meet the overheating requirements, classrooms on the north façade will be provided with openable (dB LAeq,30mins) reduction index level (dBA) windows and an attenuated return air path into the corridors to allow for natural cross-ventilation during times Rw + Ctr (dB) of peak cooling load. At this stage of the assessment it has been assumed that this will be required for no All spaces used more than 200 hours of the year and therefore the IANL relaxation defined in BB 93 is applicable (see Section North 60 for teaching or 40 23 2.2.1). learning Any future changes to the cooling or ventilation strategy should be confirmed with the acoustic consultant so All spaces used South 63 for teaching or 35 31 that the effect on internal ambient noise levels can be appropriately considered. learning Table 7 - Minimum glazing sound insulation performance requirements 4.2.2 Main Hall The hall will be provided with a dedicated Air Handling Unit (AHU) with local control, which will determine the 4.2 Ventilation strategy quantity of fresh air and cooling needed in order to maintain the required CO2 levels and temperature set- points. Based on the calculated noise level incident at the façade locations and on achieving the BB93 IANL criteria, a hybrid ventilation strategy has been developed for the Matthewsgreen School. 4.3 Dividing floors Due to the relatively high external noise levels at the south façade, it is anticipated that the use of natural ventilation through open windows will be likely to result in the IANL criteria being exceeded. Therefore, it is The current floor build-up is proposed to comprise 75mm screed laid on 10mm acoustic underlay on 250mm not recommended for the school to rely upon open windows to provide normal ventilation rates on the south hollow-core concrete planks, with exposed soffits in the rooms beneath. façade. This build-up is expected to provide the required on-site airborne sound insulation performance required by 4.2.1 Classrooms BB93 (listed in Section 2.2.4). However, when an acoustic underlay product is selected it should be checked to see that the overall floor construction will meet the impact sound insulation requirements of BB93. As noted in the previous stage 2 report, acoustic modelling demonstrated that noise levels at the south façade of the building are likely to exceed the BB93 allowances for naturally ventilated spaces. Due to this constraint, It should be noted that if any of the teaching spaces, in particular the studio, are to be used for activities classrooms on the south façade will be provided with mechanical heating and cooling. involving high level activity noise such as music, the floor construction may need to be reviewed to provide higher sound insulation. Classrooms on the both façades of the building will be provided with façade mounted Enhanced Natural Ventilation Units (ENVUs) in order to provide the required fresh air to each classroom. Each unit must be 4.4 Internal partitions capable of providing the following minimum level of sound attenuation: This Section must be read in conjunction with the latest acoustic mark-ups (see Appendix B). The drawings indicate the sound insulation requirements of partitions, based on achieving the on-site airborne sound insulation requirements as outlined in Section 2.2.4.

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Specifications are based on partitions being full height from structural floor to structural soffit with no It is understood that proposals currently include a moveable partition between the Nursery and Reception penetrations for glazing or ventilation within the dividing element, except where stated. If there is a rooms. The minimum airborne sound insulation performance between the two rooms is required to comply requirement for glazing or ventilation openings within partitions, performance requirements may need to be with the BB93 requirements of minimum 45 dB DnT,w. adjusted accordingly. Due to less favourable mounting conditions, which decrease the effectiveness of the acoustic seals, moveable Table 9 shows some examples of drylining partition constructions to achieve the airborne sound insulation partitions typically can only achieve a maximum on-site 40 dB R’w and a maximum laboratory performance of performance requirements. 55 dB Rw. As such, although the movable partition will provide greater flexibility for the school, the sound insulation between the two spaces will be limited when in simultaneous use, potentially resulting in disruption from noisy activities in one space being clearly audible in the other. Mineral Rating wool in Cavity/stud Typical construction Should this moveable partition be absolutely required, this will need to be justified as an alternative (dB) cavity performance standard (APS), in accordance with Section 0.5 of BB93. It is recommended that an airborne (mm) sound insulation criteria is sought with on-site performance of 40 dB DnT,w specified as a minimum standard. 2 layers 12.5 mm SoundBloc board (≥10.6 kg/m² 70 mm metal Acoustud 25 per layer) either side An alternative performance standard for the moveable partition is provided in Appendix C to this report, and the process described in more detail. 50 DnT,w Min. 75 mm timber stud 2 layers 12.5 mm SoundBloc board (≥10.6 kg/m² with Gypframe RB1 50 per layer) either side Alternatively, the moveable partition could be replaced with a fixed partition which provides a sound insulation resilient bar either side rating of at least 45 dB DnT,w. 2 layers 12.5 mm SoundBloc board (≥ 10.6 kg/m² 70 mm metal C studs 50 per layer) either side 4.4.3 Moveable partition – community spaces

45 DnT,w Min. 75 mm timber stud Current proposals also include an operable wall between the Community Hall and the Multi-Purpose Room. 2 layers 12.5 mm SoundBloc board (≥ 10.6 kg/m² with Gypframe RB1 50 per layer) either side Regarding a moveable partition to a hall, Section 1.2.2. of BB93 provides the following exception for operable resilient bar walls which could be applied in this case: 1 layer 12.5 mm plasterboard (≥ 8 kg/m²) either 48 mm metal C studs 25 side “c) Where there is an operable wall or folding partition between a teaching area and a hall, the DnT,w between the spaces should be at least 40 dB. The end user should be made aware that the sound insulation 40 Rw 1 layer 15 mm SoundBloc board (≥ 12.6 kg/m²) performance of the operable wall may not facilitate simultaneous independent use of the spaces on either Min. 75 mm timber stud - either side side.”

1 layer 12.5 mm SoundBloc board (≥ 10.6kg/m2) 70 mm metal C studs - This is considered a reasonable approach to a community space, assuming that the operational benefits for either side opening up the spaces outweigh the acoustic needs of the affected spaces. Suitable timetabling would need 45 Rw to be developed such that noisy activities within one space do not occur at the same time as noise-sensitive 1 layer 15 mm fibre reinforced plasterboard (≥ 70 mm metal C studs 25 activities in the other. 13.9kg/m2) either side Table 9 - Example drylining internal partition construction 4.5 Internal glazing Suitable acoustic detailing and quality of workmanship on site will be needed to allow the expected performance to be achieved on site. All internal glazing should provide airborne sound insulation performance equivalent to that of the partition in which it is located. Alternative board types may be used, providing they equal or exceed the minimum mass per unit area (kg/m²) of those specified above. In corridor walls, the glazing sound insulation performance can be relaxed slightly, however every care must be taken such that the overall rating of the partition is not degraded. The following rule of thumb can be 4.4.1 Flanking transmission applied to set the minimum performance for glazing.

Flanking paths will include any floors, ceiling, separating wall and cladding constructions, and noise transmitted via flanking paths should be sufficiently controlled in order to achieve the on-site airborne and % of wall area which comprises glazing Maximum reduction in glazing Rw permitted impact sound insulation performance requirements. < 10 % -3dB

As such, all penetrations and junctions will need to be carefully detailed during the next design stage in order 10 - 20 % -2dB to maintain the acoustic separation (both horizontal and vertical adjacencies) between all occupied spaces 25 – 45 % -1dB within the Matthewsgreen School.

4.4.2 Moveable partition - school

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Table 10 - Internal glazing sound insulation performance Mid frequency Class of Minimum required Any instances where a reduction in internal glazing sound insulation performance is proposed should be Space reverberation time, absorbent absorption area reviewed by the acoustic consultant prior to construction or installation on site, even if the reduction is in line Tmf (seconds) material % of floor area with the above rule of thumb. A 47 % Studio** 0.8 – 1.2 4.6 Doorsets C 79 % T ≤ 0.4 averaged from Doorsets in corridor partitions to acoustically sensitive spaces must provide a minimum laboratory airborne 125 Hz to 4kHz octave A 100 % sound insulation performance of 30 dB Rw or 35 dB Rw. These ratings can be achieved by a well fitted solid band centre frequencies core doorset where the door is sealed effectively around its perimeter within a substantial frame. A doorset is SEN typically comprised of a particle core or laminated softwood core, with the following specifications: and T ≤ 0.6 s in every octave C 168 % band in this range. Performance rating Mass per unit area Thickness A 32 % 2 30 dB Rw 27 kg/m 44 mm Library ≤ 1.0 C 52 % 2 35 dB Rw 29 kg/m 54 mm Grp Area A 29 % Table 11 - Doorset specifications (open plan ≤ 1.2 C 46 % The Rw requirement for the door at their indicative locations is shown on the acoustic mark ups AS00(80)1001 resource/breakout area) and AS01(80)1001, which are also attached in Appendix B to this report. A 38 % Meeting room ≤ 0.8 Acoustically rated doorsets must not be undercut or have grilles for ventilation or any other purpose. C 64 % A 32 % Staff Room† ≤ 1.0 4.7 Reverberation control C 55 % A 25 % Reverberation control is a key design factor in providing successful educational facilities. Appropriate Offices etc. † ≤ 1.0 reverberation times help to enhance speech intelligibility, reduce noise build up and provide a comfortable C 42 % atmosphere for users of the building. A 58 % Multi-Purpose Room† 0.8 – 1.2 Advice included in this Section is provided based on achieving the BB93 criteria. C 94 % A 80 % 4.7.1 Absorption material performance Community Hall† 0.8 – 1.2 C 130 %

The minimum absorption coverage to meet the BB93 reverberation time targets as outlined in Section 2.2.6 * Typically, acoustic absorption is applied to all available surface of the soffit/ceiling to provide an even distribution of acoustic are provided in Table 12. For the purpose of informing the building design, the minimum required absorption absorption. However, due to the large volume and higher ceiling of the hall, additional acoustic absorption to the wall surfaces will be required in order to achieve the BB93 reverberation time criterion for the room’s intended use. Wall acoustic absorption should areas have been calculated based on Class A and C acoustic absorption. The absorption coefficients of the also be distributed evenly wherever possible, but it is useful to apply the wall absorption behind/to the sides of the audience two absorption classes are provided in Table 13. location to improve speech projection. ** It is assumed that the studio is a multi-purpose space for drama / occasional music etc. The absorption requirements have been calculated based on hard floor finishes. If carpet floor finishes are to † Acoustic absorption in ancillary / community spaces are guidance values only and are not a requirement of building regulations. be incorporated, the above acoustic absorption coverage requirements may be reduced slightly. Table 12 - Acoustic absorption requirements

Mid frequency Class of Minimum required Octave band centre frequency, Hz Absorption coefficients, α Space reverberation time, absorbent absorption area Absorption class Tmf (seconds) material % of floor area 125 250 500 1k 2k 4k A 70 % A 0.60* 0.70 0.90 0.90 0.90 0.80 Classrooms ≤ 0.6 C 117 % C 0.40* 0.60 0.60 0.60 0.50 0.55

*Acoustic absorption at 125Hz is listed for information only A 110 % Main Hall* 0.8 – 1.2 Table 13 - Absorption coefficients of Class A and C acoustic absorption C 179 %

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4.7.2 Circulation spaces

Advice relating to absorption in corridors and stairwells detailed in Approved Document E of the Building Regulations 2010 should be applied to enclosed circulation spaces such as corridors and stairwells (excluding emergency stairwells). This advice is detailed below.

Absorption Space Recommended area coverage class

Corridors 100 % of floor area Class C

Stairwells and 100% Class D common areas Or 50% Or Combined area of: Stair treads; Class C Upper surface of the intermediate landing; Upper surface of the landings (excluding ground floor), and; Ceiling area on the top floor Table 14 - Acoustic absorption requirements in circulation spaces

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M&E Acoustics 5.3.2 Crosstalk Where ductwork passes through a partition, or where rooms share common ductwork, crosstalk attenuation should be applied to ensure that the acoustic performance of the existing partitions is not degraded. 5.1 External plant noise emission Wherever possible, ductwork layouts should be designed such that they do not pass between acoustically To meet with the requirements of Planning Condition 52, the following noise emission limit at 1m from the rated partitions separating teaching spaces. nearest noise sensitive receptor has been set out for new building services plant associated with the proposed development. This limit should be used to select appropriate equipment and specify any noise attenuation 5.3.3 Regenerated noise measures required All ductwork elements will contribute to regenerated noise within the ductwork. Attenuators, dampers and vanes will disrupt the airflow and generate noise within the ductwork. The air speed within each system zone Existing background noise Plant noise level limit dB Time period should be selected to limit regenerated noise levels. level dB LA90 LAeq, T Terminal elements such as grilles should be selected to enable the required background noise level criterion Daytime (07:00-23:00 hrs) 55 50 within rooms to be satisfied. Note 5.3.4 Air velocity The plant noise limit has been set out based upon the background noise levels presented in the ES Chapter (background noise data used provided in Appendix D). As such, the suitability of this noise emission limit is limited to For each doubling of air velocity, regenerated noise across a fitting will rise by approximately 15 dB. Thus, it is the accuracy of the background noise level data provided in the ES Chapter. essential that ducts should be sized to keep air velocities suitably low in acoustically sensitive areas.

Table 15 - Plant noise limit 5.3.5 Pipework The above limit is applicable to the cumulative noise level from all new items of plant when running under normal operation, and a further 5 dB correction is applicable if the new plant has any tonal characteristics. With regards to pipework noise, there are four primary acoustic concerns with piping systems:

The nearest receptor is likely to be a dwelling as residential areas are currently under construction on three  Excessive water flows and pressures causing high levels of broadband noise; sides of the school site.  Inadequate vibration isolation for noise and vibration from pipes, pumps and fan-powered equipment;  Unsealed penetrations through sound rated walls and slabs, and; 5.2 Plant isolation  Undersized valves or their actuators causing cavitation, chatter or whistle. Large plant items should be mounted on a heavy base/framework and fixed to an inertia slab rather than Therefore, good space planning is imperative. Pipework that may cause these problems should be kept away suspended from the ceiling/soffit, to prevent structure-borne noise transfer. from critical spaces and vibration isolation should be used to ensure no rigid contact between piping and surrounding structures or walls. Most mechanical equipment including fans, chillers, AHUs and pumps will require isolation from the building structure by means of spring mounts or similar isolators. Such isolation measures should provide 95% Cast iron pipe is preferable to PVC for waste/drain lines. Where cast iron pipe is not possible, pipe lagging efficiency. (and / or boxing in with plasterboard) may be required.

Flexible connections should be employed between isolated plant and non-isolated components such as pipes 5.3.6 Services penetrations and ductwork. These connections should allow unrestricted movement of the plant item. Wherever possible, services must not pass through partitions dividing adjacent teaching spaces, but be routed Plant and/or associated equipment located in the ceiling voids or exposed to potential noise sensitive spaces via an adjoining corridor or non-teaching space. may need to be acoustically lagged (or boxed in using plasterboard) to mitigate any case radiated noise generated by plant. Where there is no other option but to pass services through sound-resisting partitions, care must be taken to see that the acoustic integrity of the partition is not compromised.

5.3 General advice 5.3.7 Service Risers / SVPs

5.3.1 Attenuators Any pipework passing through noise sensitive spaces, or resulting in openings in partitions must be acoustically sealed. BB93 refers to guidance within Approved Document E, which states that: Primary attenuators should be incorporated into ductwork near to plant. This helps to reduce airborne noise transmission to the building to an acceptable level. ‘Pipes and ducts…should be enclosed for their full height. The enclosure should be constructed of material having a mass per unit area of at least 15 kg/m2. Either line the enclosure, or wrap the duct or pipe within the Secondary attenuators may be required in order to reduce induct noise levels and achieve the required enclosure, with 25 mm unfaced mineral wool.’ background noise level within the occupied space.

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Boxing out of services could therefore be achieved with 1 layer of Gyproc Plank (15 kg/m²), or 2 layers of 12.5 mm Wallboard (16 kg/m²), or equivalent. Any boarding option will require 25 mm unfaced mineral wool insulation to be placed inside the boxing. Any access doors or hatches to risers must provide the same level of acoustic performance and be well sealed when closed.

Boarding must be full height, taken from structural floor up to the soffit, and sealed at top and bottom using a bead of non-hardening sealant.

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Appendix A – Planning Conditions (b) calculations showing the likely impact of noise from the development; (c) a scheme of works or such other steps as may be necessary to minimise the effects of noise from the development; Condition 11 – Development briefs (d) The building shall not be used until written approval of a scheme under (c) above has been given by the “11. Before submission of reserved matters to comply with Condition 2 for the sub-phases containing: Local Planning Authority and works forming part of the scheme have been completed.”

i) the Local Neighbourhood Centre; Condition 54 – School – Protection from noise

ii) the Primary School and; “The school hereby approved shall be designed and/or insulated so as to provide attenuation against externally generated noise in accordance with a mitigation scheme to be submitted to and approved in writing iii) Community Facilities by the Local Planning Authority before its construction commences. The scheme shall ensure that all noise implications, but specifically the future noise implications of the Northern Distributor Road (assuming full traffic as defined on the Land Use Parameter Plan, Drawing No 2197-A-1010-G, a Development Brief for each of flows at the outset), the A329(M) and Toutley Industrial Estate are mitigated so that internal and external these parts of the site shall be submitted to and approved in writing by the Local Planning Authority and the ambient noise levels comply with Building Bulletin 93 – Acoustic Design of Schools – a Design Guide or any details pursuant to reserved matters shall be in accordance with the approved Development Brief. document that supersedes it.

[…] No part of the school building or external space shall be occupied or brought into use until the noise mitigation measures to serve it have been implemented in accordance with the approved details and the measures shall The Primary School Development Brief shall contain: be retained thereafter.”

[…]

iv) a strategy for achieving noise levels in accordance with Building Bulletin 93 – Acoustic Design of Schools – a Design Guide or any document that supersedes it including an external noise level not exceeding 55 dB LAeq,30min for unoccupied outdoor areas and an external teaching area where the

noise level is below 50 dB LAeq,30min.”

Condition 51 - Proposed Development - Protection from external noise

“Prior to the commencement of development, details of a scheme of works, for protecting the occupiers of the development (including the residual accommodation, open spaces and the school) from externally generated noise for each sub phase shall be submitted to and approved in writing by the Local Planning Authority. All works forming part of the scheme shall be implemented before any dwelling is first occupied”.

Condition 52 – Noise from services associated with new buildings

“Noise resulting from the use of plant, machinery or equipment shall not exceed a level of 5dB(A) below the existing background level (or 10dB(A) below if there is a particular tonal quality) when measured according to British Standard BS4142-2014, at a point one metre external to the nearest noise sensitive premises.”

Condition 53 – Prior to installation on a building the following shall be submitted to the Local Planning Authority:

“(a) written details concerning any proposed air handling plant, chillers or other similar building services including:

(i) the proposed number and location of such plant as well as the manufacturer’s information and specifications.

(ii) the acoustic specification of the plant including general sound levels and frequency analysis under conditions likely to be experienced in practice.

(iii) the intended operating times.

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Appendix B – Acoustic strategy drawings

Acoustic strategy drawings for Matthewsgreen School are included in the following two pages.

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175 Note 1: Plant Partitions surrounding the plant room have been based on an assumed 1014076 reverberant noise level no greater 5147552-ATK-Z1-01-DR-A-1010_P3 P3 than 80 dBA. Note 2: To minimise flanking noise via Adjacent corridors, it is recommended that doorsets doorsets are separated as far apart as practicable, either side of a DO NOT SCALE FROM THIS DRAWING partition. Note 3: Lift There should be no hard contact Notes between the lift shaft and lightweight partitions of noise-sensitive adjacent spaces. Note 4: Open The library is open to the corridor and Plan Library as such has been classed as an Area open plan resource area, rather than an enclosed library. Note 5: Due to the presence of nearby open Upgraded plan teaching spaces, the acoustic partitions rating for these partitions and doorsets have been increased. Note 6: Servery As per the guidance in Building Bulletin 93, Section 1.2.3 Exceptions, a serving hatch between a kitchen and hall should have as high a level of sound insulation as practicable (not less than 18 dB R ). Note 7: Movable While there is not specific guidance for partition the rating of movable partitions -Classbase between classbases, it is recommended that a movable partition, rated to achieve a performance 10 dB higher than the rating of a solid partition, be set, resulting in a performance of 55 dB Rw. It should be noted that movable partitions will not provide the same level of sound insulation performance as a solid partition and may not facilitate simultaneous use of both spaces. A timetable should be created for scheduled use of each space. Note 8: Movable Building Bulletin 93, Section 1.2.3 partition Exceptions, the sound insulation -Hall performance of a movable partition separating a teaching area and hall should be at least 40 dB DnT,w. It is recommended that a movable partition rated to achieve a performance of at least Rw 60 dB be specified. Note 9: Natural It should be noted that rooms with full ventilation natural ventilation strategies (excluding SEN spaces) may relax the required IANL by up to 5 dB.

00-001 Community Hall 200.0 m2

00-008 M.WC 00-009 00-007 M.WC Kitchenette 17.5 m2 00-010 F.WC 00-019 Clks 00-011 Ext. Store 00-002 00-016 Lobby / Clks Clks F.WC 00-030 Clks Multi-Purpose Room Nur. Ext. St. 6.5 m2 Clks Circulation 12.0 m2 Circulation 103.0 m2 00-012 00-021 00-028 00-036 00-041 Clks 00-048 Clks Clks Clks Matthewsgreen Primary School WC/B'by 00-020 Reception Classroom 00-006 Nursery Reception Classroom 4.5 m2 Nur. WC 66.0 m2 61.5 m2 61.5 m2 61.5 m2 61.5 m2 Child'n WC 00-017 12.0 m2 00-033 00-040 00-047 C. St. R. WC's P. WC 13.5 m2 00-013 Clrn Store Library 17.5 m2 44.0 m2 10.5 m2 Office 2 Store Store Store 00-005 8.0 m2 WOKINGHAM BOROUGH COUNCIL Office 1 00-018 7.5 m2 Changing Places 00-022 00-024 VOID ABOVE Grp Area VOID ABOVE Grp Area VOID ABOVE 12.0 m2 Nur. Kitchenette St. Server C. St. S.WC S.WC ATKINS 00-004 00-003 12.0 m2 6.0 m2 00-080 Circulation 00-051 00-050 Lobby 00-025 Circulation 76.5 m2 Circulation Staircase 6.5 m2 PE Store 70.0 m2 GROUND FLOOR 95.5 m2 35.5 m2 ACOUSTIC STRATEGY 00-067 Lift 00-070 00-066 Store 00-061 Store Sick Bay Off. / Mtg Hygiene Repro P. WC 00-014 00-078 9.0 m2 10.5 m2 11.0 m2 10.5 m2 AS00(80)1001 S2 - For Information Mech. Plant Stairs 00-062 C.St 00-055 00-052 00-015 Acc. WC 36.0 m2 00-027 24.0 m2 Classroom Classroom Studio Kitchen 00-026 00-075 Chair St. 00-076 00-068 62.5 m2 Clks 00-058 Clks 62.5 m2 57.0 m2 65.0 m2 Main Hall Lobby 1014076 NTS 14.0 m2 00-074 Gen. Office Head / Mtg Circulation 182.0 m2 19.5 m2 00-065 Int. Room 20.5 m2 17.0 m2 00-077 PPA 7.5 m2 Clks JW MRE TN P2 Elec. Plant 7.0 m2 Clks 18.0 m2

4th Floor 15 Colmore Row Birmingham, B3 2BH Tel: +44 (0)121 262 2720

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5147552-ATK-Z1-01-DR-A-1011_P3 P3 Note 1: Lift There should be no hard contact between the lift shaft and lightweight partitions of noise-sensitive adjacent spaces. Note 2: SEN This room has been designed DO NOT SCALE FROM THIS DRAWING specifically for hearing impaired students. Notes "Reverberation Time criteria for teaching spaces specifically for pupils having special hearing and communication needs:  T30 ≤ 0.4 seconds averaged from 125Hz to 4kHz OBCF; and  T30 < 0.6 seconds in every OB in this range." Due to the sensitive nature of the SEN spaces, it is recommended that the floors achieve an airborne sound insulation of at least 55 dB Rw. Note 3: Natural It should be noted that rooms with full ventilation natural ventilation strategies (excluding SEN spaces) may relax the required IANL by up to 5 dB.

01-002 01-004 SEN Res. P. WC 12.5 m2 38.0 m2 01-007 01-008 01-010 01-012 01-014 Food/Sci/D&T Classroom Classroom Classroom Classroom 61.5 m2 01-001 55.0 m2 55.0 m2 55.0 m2 55.0 m2 SEN / MI 12.0 m2

C.Stk Acc. WC Matthewsgreen Primary School Store Store Store Store

VOID VOID VOID Spec. St. 01-031 C.Stock Clks Clks ClksClks Clks Clks Clks 01-016 Circulation Stairs 59.5 m2 01-032 01-039 29.5 m2 WOKINGHAM BOROUGH COUNCIL Circulation Circulation 01-030 50.0 m2 40.0 m2 Stairs 40.0 m2 ATKINS Store Store Store Store Lift Riser

01-024 FIRST FLOOR 01-026 01-022 01-020 01-017 01-029 Classroom ACOUSTIC STRATEGY ICT Suite Classroom Classroom Classroom Staff Room 55.0 m2 62.0 m2 55.0 m2 55.0 m2 55.0 m2 48.0 m2 DN AS01(80)1001 S2 - For Information

1014076 NTS

JW MRE TN P2

4th Floor 15 Colmore Row Birmingham, B3 2BH Tel: +44 (0)121 262 2720

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 written confirmation from the school client body of areas of non-compliance, together with the justification Appendix C - Alternative performance standards for the need and suitability of the APS in each space”

An alternative performance standard (APS) for the moveable partition between the nursery and reception room is provided below:

Item Airborne sound insulation between spaces divided by a moveable partition

Location Nursery and Reception room

Reason for A moveable partition is proposed in this location to enable the two rooms to be alternative opened up into one larger space, for operational practicality purposes. standard

BB93 criteria 45 dB DnT,w

Alternative 40 dB DnTw standard

Possible practical Noisy activities in one space are likely to be audible in the other when in implications simultaneous use, and may result in disruption

BB93 APS guidance

Section 0.5 - Alternative performance standards

“Alternative performance standards (APS) may be adopted for new buildings, where justified by specific educational, environmental, or health and safety requirements. An APS should not normally be of a lower standard than those shown for refurbishment in the tables given n section 1 or those described in the exceptions in section 1. Where the performance standard for refurbishment is proposed as an APS for a new school, a full and proper case must be made and documented to justify the decision.

Any APS must be justified by a suitably qualified acoustician and the school client body on the grounds of educational, environmental or health and safety need. The contractor, with the assistance of the project acoustician, should make the building control body and the client aware of the practical implications with respect to the operation of the space.

The procedure set out in section 2.2 must be followed and fully documented in the project’s design risk register, building manuals or other documentation and this documentation should be made available to the school governors, staff and parents of pupils at the school, to ensure that the client and users of the school have the opportunity to understand the effect of any reduction in standards.”

Section 2.2. - Alternative performance standards

“In some circumstances alternative performance standards may be appropriate for specific areas within individual schools for particular educational, environmental or health and safety reasons (see section 0.5). In these cases, the following information should be provided to the building control body:

 a written report by a specialist acoustic consultant clearly identifying (a) all areas of non-compliance with the performance standards (b) the proposed alternative performance standards and (c) the technical basis upon which these alternative performance standards have been chosen

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Appendix D – Background noise level data

The background noise data used to set plant noise limits was taken from the Environmental Statement (ref), from which two relevant sections have been reproduced below, to help illustrate how the data was selected.

This approach was taken because, at the time of writing, the Matthewsgreen Site is an active construction site and noise surveys are no longer feasible. The measurement results from position MP2 (see map below) have been used as this was considered the closest position to the proposed school.

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