Oakdale Primary School Playground Noise Assessment...May 04, 2017 · Playground Noise Assessment Page 6 Oakdale Primary School Report 17/0074/R2/0 // 4th May 2017 8 hour school day

Oakdale Primary School

Playground Noise Assessment Report 17/0074/R2

This report and associated surveys have been prepared and undertaken for the private and confidential use of our client only. If any third party whatsoever comes into possession of this report, they rely on it at their own risk and Cole Jarman Limited accepts no duty or responsibility (including in negligence) to any such third party. Cole Jarman Limited Reg. in England and Wales No. 7102436 [email protected] www.colejarman.com

Head Office +44 (0)1932 829007 Manchester Office +44 (0)161 2093644 John Cree House, 24B High Street, Addlestone, Surrey, KT15 1TN Peter House, 1 Oxford Street, Manchester, M1 5AN

Oakdale Primary School

Playground Noise Assessment Report 17/0074/R2

Hamson Barron Smith

3 Maltings Place

169 Tower Bridge Road

London

SE1 3JB

Revision Description Date Prepared Approved

0 1st Issue 4th May 2017 Tim Fox Johnny Berrill

Playground Noise Assessment

Page 2 Oakdale Primary School Table of Contents Report 17/0074/R2/0 // 4th May 2017

Table of Contents

1 Introduction 3

2 Site Layout 3

2.1 Existing Layout 3

2.2 Proposed Layout 3

2.3 Nearest Noise Sensitivities 3

3 School Noise Assessment Guidance 3

4 Assessment 5

4.1 Existing Noise Levels 5

4.2 Calculations and Assumptions 5

4.3 Results 6

5 Conclusions 7

Attachments

Glossary of Acoustic Terms 17/0074/SP1 Site plan showing current playground layouts

17/0074/SP2 Site plan showing proposed playground layouts

17/0074/SCH1 Attended survey results

End of Section


Page 3 Oakdale Primary School Report 17/0074/R2/0 // 4th May 2017

1 Introduction

1.1 As part of the refurbishment and new build works taking place at Oakdale Primary School, it is proposed for the playground areas to change location and size. Due to this, it has been raised that a playground noise assessment should be undertaken as part of the planning application.

1.2 This report describes the assessment of the likely noise change due to the proposed school development based on prediction of existing and resultant noise levels from the school external play areas.

2 Site Layout

2.1 Existing Layout

2.1.1 The school currently occupies playgrounds around the site. These are shown in green on the attached site plan 17/0074/SP1.

2.1.2 Playing fields for soft play wraps around the school to the west and north of the site. The largest area of hard play is located at the south-east corner of the site. A nursery with outdoor play area is located at the east of the side, to the north-east of the main school building. Between the western side of the school building and the playing fields are additional hard play areas.

2.2 Proposed Layout

2.2.1 The proposed layout is shown on the attached site plan 17/0074/SP2. As part of the development works, playground areas are to move and/or change in size; as shown in green on the site plan.

2.2.2 The hard play area to the south-east is to be replaced with a car park. A new hard and soft play area is proposed to be located to the east of the new extension block. The hard play areas to the west are to increase in size.

2.3 Nearest Noise Sensitivities

2.3.1 Residential houses bound the site to the east and south of the site. Changes from playground noise levels will be assessed at these positions. The assessment positions are shown on the attached site plan 17/0074/SP2.

3 School Noise Assessment Guidance

3.1 When assessing changes in the noise climate due to redevelopment of the site at nearby sensitive receivers, the approach taken is to compare LAeq noise levels in the existing and proposed scenarios. The basis for this form of assessment can be found in the consultation ‘Guidelines for Noise Impact Assessment’ written by the Institute of Environmental



Management and Assessment and the Institute of Acoustics. Having established the likely change in noise levels, the significance of the change can be determined.

3.2 While PPG24 has been revoked, it still contains some technical content which remains valid and relevant. The glossary states:

“A change of 3 dB(A) is the minimum perceptible under normal conditions, and a change of 10 dB(A) corresponds roughly to a halving or doubling the loudness of a sound.”

3.3 The IEMA guidelines 2014 for environmental noise impact assessment back this statement by stating:

“For broadband sounds which are very similar in all but magnitude, a change or different in noise level of 1 dB is just perceptible under laboratory conditions, 3 dB is perceptible under most normal conditions, and a 10 dB increase generally appears to be twice as loud. These broad principles may not apply where the change in noise level is due to the introduction of a noise with different frequency and/or temporal characteristics compared to sounds making up the existing noise climate. In which case changes of less than 1 dB may be perceptible under some circumstances.”

3.4 The minimum perceptible change of 3 dB(A) is also implicit in other assessment methods. For example in BS 5228:2009 Code of Practice for Noise and Vibration Control on Construction and Open Sites, for certain ambient noise levels, it recommends limiting construction noise such that it does not result in an increase in total noise levels of more than 3 dB(A).

3.5 Taking account of these factors the following table relates changes in overall sound levels to normal human response.

Sound Level Change, dB(A)

Interpretation

Subjective Impression Impact Description 0.0 No change No Change 0.1 to 2.9 Imperceptible change in loudness Minor 3.0 to 4.9 Perceptible change in loudness Moderate 5.0 to 9.9 Up to doubling or halving of loudness Substantial 10.0 or more More than doubling or halving of loudness Major

T1 Typical human interpretation of impact arising from a change in sound level

3.6 It should be noted that the presentation of changes in sound level to one decimal place in the above table is not a reflection of the accuracy of any assessment undertaken but rather serves to provide a clear threshold between adjacent impact descriptions.



3.7 For the assessment of changes in operational noise levels, a noise level change of +2.9 dB or less, corresponding to a Minorimpact (at worst) is considered to be consistent with the aims of NPPF and NPSE, and therefore acceptable.

4 Assessment

4.1 Existing Noise Levels

4.1.1 A noise survey has been undertaken previously on site between 11h00 and 14h00 on Friday 24th February 2017 with attended measurements taken towards the north of the site (MP1 on the attached site plan 17/0074/SP1).

4.1.2 Measurements of the LAeq, LAmax and LA90 indices were made over the time periods detailed in the schedule (see the glossary of Acoustic Terms for an explanation of the noise units used).

4.1.3 Noise measurements were made using the equipment listed in table T2.

Item Manufacturer Type Sound Level Analyser Norsonic 118 Acoustic Calibrator Norsonic 1251 Weatherproof windshield Norsonic 1212

T2 Equipment used during attended noise survey

4.1.4 The microphone was fitted with a windshield and the sound level meter was calibrated before and after the survey to ensure a consistent and acceptable level of accuracy was maintained throughout.

4.1.5 Weather conditions during the survey setup were cold, dry and overcast with some breeze.

4.1.6 The results of the attended survey are shown in the attached schedule 17/0074/SCH1, which show a minimum LAeq,30min level of 55 dB. These measurements were taken without school activities taking place; the noise climate was controlled by road traffic noise. This measured level, the lowest LAeq,30min during a period with no playground activity, therefore represents a pessimistic baseline level for the playground noise assessment.

4.2 Calculations and Assumptions

4.2.1 In order to assess both the short term (15 minute, LAeq,15min - representative of typical levels during playtime) and long-term (full school day, LAeq,8hr) noise impact, the following assumptions were made:



8 hour school day – 08:30 to 16:30 3 break-time out door periods of 20, 60 and 15 minutes each, totalling 95 minutes Break time noise levels dominate during these periods, no outdoor noise for the rest of the

school day

4.2.2 Based on noise levels from previously measured playground noise, a worst case noise level from free play of LAeq,T of 83 dB at 1m from the edge of a typical playground with area of 75m2 has been used within our assessment.

4.2.3 The outdoor noise level for each playground was corrected for area and number of students. Propagation to the residential façade was calculated as for a standard area source. A 3 dB façade correction was also applied in all cases.

4.2.4 The attached 17/0074/SP1 and 17/0074/SP2 show the playground areas considered as part of this assessment. The larger open playing area and northern playing fields are to be retained under their current use and therefore are not considered as part of this assessment.

4.3 Results

4.3.1 Based on the above, the following LAeq,T levels were calculated at the residential façade. LAeq,8hr school day noise levels were calculated assuming a day consisting of 95 minutes constant outdoor activity.

AP1 AP2

LAeq,15min LAeq,8hr LAeq,15min LAeq,8hr

Existing Noise Levels 55 55 55 55

Calculated Existing Playground Noise Levels

55 55 57 56

Predicted Noise Playground Levels 57 56 57 55

T3 Comparison of existing and predicted noise levels at nearest residential façade

4.3.2 The results above show that for AP2, either a reduction or no change in noise level is expected between the existing and proposed playground layouts and that a change of no more than +2 dB is expected between the existing noise levels without playground activity and from playground activity with the proposed layouts, corresponding to a Minor Impact. In comparing the noise levels under current playground use to the proposed playground layout on the same calculation basis it is found the noise levels are expected to be similar or a minor reduction, corresponding to an impact level of No Change.

4.3.3 For AP1, a noise level change of less than +2 dB has been calculated for the proposed layout in comparison to both the existing noise levels with and without playground activity,



corresponding to a Minor impact at worst. This is due to the relocation of the eastern play area, moving closer to AP1.

4.3.4 As both positions experience a Minor impact at worst under pessimistic calculation conditions, this is considered to be within the aims of NPPF and NPSE, and therefore acceptable.

4.3.5 It should also be noted that whilst noise levels are increasing by a minor amount at some of the residential façades, other properties will expect a decrease (or at least no change) in noise levels due to the new play area layout.

5 Conclusions

5.1 As part of the refurbishment and new build works taking place at Oakdale Primary School, it is proposed for the playground areas to change location and size. Due to this, it has been raised that a playground noise assessment should be undertaken as part of the planning application.

5.2 This report has outlined the details and results of an assessment on the likely change in noise levels due to the proposed new layout and constructions.

5.3 Calculations have been undertaken based on the existing and proposed school layouts. Any assumptions made have been done so to provide a pessimistic forecast of the noise levels at the relevant residential façades due to the proposed new school layout.

5.4 It has been shown that, based on current proposals, noise levels over both the short term and a typical full school day are expected to correspond to a Minor impact at worst. This is considered to be within the aims of NPPF and NPSE, and therefore acceptable.

End of Section


Page 8 Oakdale Primary School Glossary of Acoustic Terms Report 17/0074/R2/0 // 4th May 2017

Glossary of Acoustic Terms

LAeq:

The notional steady sound level (in dB) which over a stated period of time, would have the same A-weighted acoustic energy as the A-weighted fluctuating noise measurement over that period. Values are sometimes written using the alternative expression dB(A) Leq.

LAmax:

The maximum A-weighted sound pressure level recorded over the period stated. LAmax is sometimes used in assessing environmental noise when occasional loud noises occur, which may have little effect on the LAeq noise level. Unless described otherwise, LAmax is measured using the “fast” sound level meter response.

LA10 & LA90:

If non-steady noise is to be described, it is necessary to know both its level and degree of fluctuation. The LAn indices are used for this purpose. The term refers to the A-weighted level (in dB) exceeded for n% of the time specified. LA10 is the level exceeded for 10% of the time and as such gives an indication of the upper limit of fluctuating noise. Similarly LA90 gives an indication of the lower levels of fluctuating noise. It is often used to define the background noise.

LA10 is commonly used to describe traffic noise. Values of dB LAn are sometimes written using the alternative expression dB(A) Ln.

LAX, LAE or SEL

The single event noise exposure level which, when maintained for 1 second, contains the same quantity of sound energy as the actual time varying level of one noise event. LAX values for contributing noise sources can be considered as individual building blocks in the construction of a calculated value of LAeq for the total noise. The LAX term can sometimes be referred to as Exposure Level (LAE) or Single Event Level (SEL).

End of Section

Cole Jarman Limited Reg. in England and Wales No. 7102436 [email protected] www.colejarman.com


Figure 17/0074/SP1

Title: Site plan showing current playground layouts

Project: Oakdale Primary School

Date: May 2017 Scale: Not to scale

AP1

AP2

MP1



Figure 17/0074/SP2

Title: Site plan showing proposed playground layouts

Project: Oakdale Primary School

Date: May 2017 Scale: Not to scale

AP1

AP2

Schedule 17/0074/SCH1

Page 1 of 1 Oakdale Primary School

Attended Noise Survey Results

Measurement Position 1

Period LAeq,30min LA1 LA90 11h00-12h00 60 72 54 12h00-13h00 56 60 54 13h00-14h00 55 62 51



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Oakdale Primary School Playground Noise Assessment...May 04, 2017 · Playground Noise Assessment Page 6 Oakdale Primary School Report 17/0074/R2/0 // 4th May 2017 8 hour school day