NOISE ASSESSMENT HOURIGAN CONNOLLY WHINBERRY VIEW, …

NOISE ASSESSMENT

on behalf of

HOURIGAN CONNOLLY

for the site at

WHINBERRY VIEW, BACUP ROAD, RAWTENSTALL

REPORT DATE: 21ST OCTOBER 2014

REPORT NUMBER: 100729

Miller Goodall Environmental Services Ltd.

214 Turton Road Bradshaw

Bolton BL2 3EE

Tel: 01204 596166

www.millergoodall.co.uk

Report No. 100729 Whinberry View, Bacup Road, Rawtenstall

Page 1 of 29 www.millergoodall.co.uk

Summary

An assessment was undertaken to predict the potential impact of road traffic noise on a proposed residential

development consisting of 29 new dwellings at a site located on Bacup Road in Rawtenstall, Lancashire. This

was undertaken to support a planning application for the development.

Measurements were made of road traffic noise affecting the proposed site and this data was used to populate

a computer noise model of the development. The model was subsequently used to predict the likely impact of

noise on future dwellings.

The assessment has indicated that the proposed building location and orientation will provide significant

shielding of noise from Bacup Road to the majority of dwellings. Those located closest to the road will require

appropriate mitigation in the form of acoustic double glazing and acoustically attenuated ventilation in order to

achieve recognised standards for internal noise. Noise levels within the majority of external amenity areas are

predicted to satisfy recognised standards with appropriate mitigation.

In conclusion, we do not foresee any reason why this application should be refused on the grounds of noise

impact.

Record of changes

Version Date Change Initials

1 16/07/13 Initial issue for comment SF

2 10/07/14 Minor updates including revised layout plan and revisions to Sections 4 and 5 to reflect recent changes in guidance

SF

3 11/07/14 Revised layout plan SF

4 17/10/14 Reassessed following changes to layout SF

5 21/10/14 Updated floor plans added to appendix SF

Prepared By Simon Faircloth MIOA Reviewed By Joanne Miller MIOA

Signed

Signed

Date 21st October 2014 Date 21st October 2014

Whinberry View, Bacup Road, Rawtenstall Hourigan Connolly

Page 2 of 29 21st October 2014

Contents

Summary 1

Contents 2

1 Introduction 4

2 Site Description 4

3 Proposed Development 4

4 Policy Context 5

4.1 Noise Policy Statement for England ........................................................................ 5

4.2 National Planning Policy Framework ....................................................................... 6

4.3 Planning Practice Guidance – Noise ....................................................................... 7

5 Acoustic Standards and Guidance 8

5.1 BS 8233:2014 Guidance on Sound Insulation and Noise Reduction for Buildings .. 8

5.2 World Health Organisation (WHO) Guidelines for Community Noise 1999 ............. 9

5.3 Possible LOAEL and SOAEL Noise Standards ....................................................... 9

6 Noise Survey 9

6.1 Measurements of Existing Noise Sources ............................................................... 9

6.2 Monitoring Results ................................................................................................ 11

7 Impact of Existing Road Traffic Noise Sources on the Development 13

7.1 Computer Modelling .............................................................................................. 13

7.2 Validation of the Noise Model ................................................................................ 13

7.3 Noise Model Predictions ....................................................................................... 13

7.4 Internal Noise Levels Assessed to BS 8233 Criteria ............................................. 14

7.5 External Noise Levels ........................................................................................... 14

8 Recommended Mitigation Measures 15

8.1 Building Envelope Construction ............................................................................ 15

8.2 Specification 1: Plots 21 to 27 inclusive ................................................................ 15

8.3 Specification 2: Plots 19 and 20 ............................................................................ 16

8.4 Specification 3: Plots 17 and 18 ............................................................................ 16

8.5 Specification 4: Plots 11 to 16 (south facing facades) ........................................... 17

8.6 Specification 5: Plots 1 to 10, plus 28 and 29 (and north facing facades) ............. 17

8.7 Acoustic barrier between plots 20 and 21, and to eastern site boundary adjacent to plot 27 ........................................................................................................................ 17

9 Conclusions 18

Glossary of Terms 19

Appendix 1a: Masterplan of Whinberry View Site 20

Appendix 1b: Proposed House Types 21



Appendix 2: Measurement Results 22

Appendix 3: Screenshots from CadnaA Noise Model 23

Figure A1: Daytime LAeq Noise Levels (with acoustic barriers) 24

Figure A2: Night-time LAeq Noise Levels (with acoustic barriers) 25

Figure A3: Night-time LAmax Noise Levels (with acoustic barriers) 26

Figure A4: Location of Proposed Noise Barriers 27

Appendix 4: Example Noise Ingress Calculation 28



1 Introduction

1.1 Miller Goodall Environmental Services Ltd (MGES) has, on behalf of Hourigan Connolly, undertaken an

assessment in respect of the impact of noise from existing road traffic sources on a proposed

residential development on the site of the former Whinberry View care home on Bacup Road in

Rawtenstall, Rossendale, Lancashire.

2 Site Description

2.1 The proposed site is a currently disused care home consisting of several one, two and three storey

buildings immediately to the north of Bacup Road, close to the roundabout junction with Bocholt Way. A

former council day care centre at No. 166 Bacup Road also forms part of the application site. An area

of green-field land approximately 0.1 Ha in area is located within the site boundary to the west of the

existing buildings with Co-operation Street located at the western boundary. Further existing dwellings

are located to the east on Lambton Gates and to the north west of the site.

2.2 A steep hill rises from the northern boundary of the site up to Newchurch Road, approximately 150 m to

the north although there is no direct access road at this location linking Bacup Road to Newchurch

Road. Further residential and commercial properties are located on both sides of Bacup Road to the

south of the site with a disused gas storage facility approximately 100 m to the south east.

2.3 Figure 1 shows the location of the proposed site.

3 Proposed Development

3.1 The proposal is to demolish the existing care home buildings and develop the land for residential use

involving the erection of 29 dwellings of 3 different house types with proposed road access to the

development site via Co-operation Street. The current masterplan for the development is provided in

Appendix 1a with plans of the various house types in Appendix 1b.

3.2 This assessment seeks to address the potential impact of existing noise sources on future proposed

residential dwellings at the development.



Figure 1: Proposed Site Location and Redline Boundary

4 Policy Context

4.1 Noise Policy Statement for England

4.1.1 The Noise Policy Statement for England (NPSE1), published in March 2010, sets out the long-term

vision of Government noise policy. The Noise Policy aims, as presented in this document, are:

1 Noise Policy Statement for England, Defra, March 2010

Bacup Road

Approximate site boundary



“Through the effective management and control of environmental, neighbour and neighbourhood

noise within the context of Government policy on sustainable development:

• avoid significant adverse effects on health and quality of life;

• mitigate and minimise adverse effects on health and quality of life; and

• where possible, contribute to the improvement of health and quality of life.”

4.1.2 The NPSE makes reference to the concepts of NOEL (No Observed Effect Level) and LOAEL

(Lowest Observed Adverse Effect Level) as used in toxicology but applied to noise impacts. It also

introduces the concept of SOAEL (Significant Observed Adverse Effect Level) which is described as

the level above which significant adverse effects on health and the quality of life occur.

4.1.3 The first aim of the NPSE is to avoid significant adverse effects, taking into account the guiding

principles of sustainable development (as referenced in Section 1.8 of the Statement). The second

aim seeks to provide guidance on the situation that exists when the potential noise impact falls

between the LOAEL and the SOAEL, in which case:

“…all reasonable steps should be taken to mitigate and minimise adverse effects on health and

quality of life while also taking into account the guiding principles of sustainable development”.

4.1.4 Importantly, the NPSE goes on to state:

“This does not mean that such adverse effects cannot occur”.

4.1.5 The Statement does not provide a noise-based measure to define SOAEL, acknowledging that the

SOAEL is likely to vary depending on the noise source, the receptor and the time in question. NPSE

advises that:

“Not having specific SOAEL values in the NPSE provides the necessary policy flexibility until further

evidence and suitable guidance is available”

4.1.6 It is therefore likely that other guidance will need to be referenced when applying objective standards

for the assessment of noise, particularly in reference to the SOAEL, whilst also taking into account the

specific circumstances of a proposed development.

4.2 National Planning Policy Framework

4.2.1 The National Planning Policy Framework (NPPF2) was published in March 2012. One of the

documents that the NPPF replaces is Planning Policy Guidance Note 24 (PPG 24) “Planning and

Noise”3.

4.2.2 Paragraph 109 of the NPPF states that the planning system should contribute to and enhance the

natural and local environment by, (amongst others) ”preventing both new and existing development

from contributing to or being put at unacceptable risk from, or being adversely affected by

unacceptable levels of soil, water or noise pollution or land stability”.

2 National Planning Policy Framework, DCLG, March 2012 3 Planning Policy Guidance 24: Planning and Noise, DCLG, September 1994



4.2.3 The NPPF goes on to state in Paragraph 123 “planning policies and decisions should aim to:

• Avoid noise from giving rise to significant adverse impacts on health and quality of life as a result

of new development;

• Mitigate and reduce to a minimum other adverse impacts on health and quality of life arising from

noise from new development, including thorough use of conditions;

• Recognise that development will often create some noise and existing businesses wanting to

develop in continuance of their business should not have unreasonable restrictions put on them

because of changes in nearby land use since they were established, and

• Identify and protect areas of tranquillity which have remained relatively undisturbed by noise and

are prized for their recreational and amenity value”.

4.2.4 The NPPF document does not refer to any other documents regarding noise other than NPSE.

4.3 Planning Practice Guidance – Noise

4.3.1 As of March 2014, a Planning Practice Guidance4 for noise was issued which provides additional

guidance and elaboration on the NPPF. It advises that when plan-making and decision-taking, the

Local Planning Authority should consider the acoustic environment in relation to:

• Whether or not a significant adverse effect is occurring or likely to occur;

• Whether or not an adverse effect is occurring or likely to occur; and

• Whether or not a good standard of amenity can be achieved.

4.3.2 In line with the Explanatory Note of the NPSE, the PPG goes on to reference the LOAEL and SOAEL

in relation to noise impact. It also provides examples of outcomes that could be expected for a given

perception level of noise, plus actions that may be required to bring about a desired outcome.

However, in line with the NPSE, no objective noise levels are provided for LOAEL or SOAEL although

the PPG acknowledges that:

“…the subjective nature of noise means that there is not a simple relationship between noise levels

and the impact on those affected. This will depend on how various factors combine in any particular

situation”.

4.3.3 Examples of these factors include:

• The source and absolute noise level of the source along with the time of day that it occurs;

• Where the noise is non-continuous, the number of noise events and pattern of occurrence;

• The frequency content and acoustic characteristics of the noise;

• The effect of noise on wildlife;

• The acoustic environment of external amenity areas provided as an intrinsic part of the overall

design;

• The impact of noise from certain commercial developments such as night clubs and pubs where

activities are often at their peak during the evening and night.

4 Planning Practice Guidance – Noise, http://planningguidance.planningportal.gov.uk/blog/guidance/noise/, 06 March 2014



4.3.4 The PPG also provides general advice on the typical options available for mitigating noise. It goes on

to suggest that Local Plans may include noise standards applicable to proposed developments within

the Local Authority’s administrative boundary, although it states that:

“Care should be taken, however, to avoid these being implemented as fixed thresholds as specific

circumstances may justify some variation being allowed”. Local Authority Requirements

4.3.5 Discussions were held with Lorna Robinson, Environmental Health Officer at Rossendale Borough

Council regarding applicable standards and proposed methodology.

4.3.6 Ms Robinson advised that internal and external noise affecting new dwellings should be assessed

using criteria and guidance found within BS 8233 and WHO Guidelines (see Section 5).

4.3.7 The proposed survey methodology was acceptable to Ms Robinson.

5 Acoustic Standards and Guidance

5.1 BS 8233:2014 Guidance on Sound Insulation and Noise Reduction for Buildings

5.1.1 This recently updated Standard provides recommended guideline values for internal noise levels

within dwellings which are similar in scope to guideline values contained within the World Health

Organisation (WHO) document, Guidelines for Community Noise (1999)5. These guideline noise

levels are shown in Table 1, below.

Table 1: BS 8233: 2014 guideline indoor ambient noise levels for dwellings

Location Activity 07:00 to 23:00 23:00 to 07:00

Living Room Resting 35 dB LAeq,16hr -

Dining room/area Dining 40 dB LAeq,16hr -

Bedroom Sleeping (daytime resting)

35 dB LAeq,16hr 30 dB LAeq,8hr

5.1.2 BS 8233:2014 advises that:

“regular individual noise events…can cause sleep disturbance. A guideline value may be set

in terms of SEL6 or LAmax,F depending on the character and number of events per night.

Sporadic noise events could require separate values”.

5 World Health Organisation Guidelines for Community Noise, 1999 6 Sound exposure level or LAE



5.1.3 BS 8233:2014 adopts guideline external noise values provided in WHO for external amenity areas

such as gardens and patios. The Standard states that it is “desirable” that the external noise does not

exceed 50 dB LAeq,T with an upper guideline value of 55 dB LAeq,T whilst recognising that development

in higher noise areas such as urban areas or those close to the transport network may require a

compromise between elevated noise levels and other factors that determine if development in such

areas is warranted. In such circumstances, the development should be designed to achieve the

lowest practicable noise levels in external amenity areas.

5.2 World Health Organisation (WHO) Guidelines for Community Noise 1999

5.2.1 The WHO Guidelines 1999 recommends that to avoid sleep disturbance, indoor night-time guideline

noise values of 30 dB LAeq for continuous noise and 45 dB LAFmax for individual noise events should be

applicable. It is to be noted that the WHO Night Noise Guidelines for Europe 20097 makes reference

to research that indicates sleep disturbance from noise events at indoor levels as low as 42 dB LAFmax.

5.2.2 The WHO document recommends that steady, continuous noise levels should not exceed 55 dB LAeq

on balconies, terraces and outdoor living areas. It goes on to state that to protect the majority of

individuals from moderate annoyance, external noise levels should not exceed 50 dB LAeq.

5.3 Possible LOAEL and SOAEL Noise Standards

5.3.1 It is acknowledged that the NPSE and the Planning Practice Guidance both advise caution when

attempting to set objective standards in relation to LOAEL and SOAEL that may be applicable to a

new development.

5.3.2 That said, the guideline values for noise within the WHO documents are set at the level of the lowest

adverse health effect (the critical health effect) and as such, the values could form the basis of the

LOAEL as referenced in the NPSE and PPG. Targeting the WHO guidelines levels as the LOAEL

should, therefore, provide a robust basis for assessment. No levels are provided within the WHO

guidance that may be directly applicable to the SOAEL and any such threshold levels will, as

indicated in the above guidance, vary depending on the specific circumstances of the development

and the noise climate in which it is located.

6 Noise Survey

6.1 Measurements of Existing Noise Sources

6.1.1 The current noise climate in the vicinity of the development is dominated by road traffic noise from

Bacup Road, including buses and HGVs. Other noise sources included birdsong which was audible

during breaks in the traffic.

6.1.2 Noise measurements were undertaken at a location consistent with the proposed development in

accordance with BS 7445-1: 20038 by Simon Faircloth of Miller Goodall Environmental Services Ltd.

7 WHO Night Noise Guidelines for Europe 2009 8 BS 7445-1: 2003 Description and measurement of environmental noise - Part 1: Guide to quantities and procedures



The calibration of the sound level meter was checked before and after measurements with negligible

deviation (<0.1 dB). Details of the equipment used are shown in Table 4.

Table 2: Noise Monitoring Equipment

Equipment Description Type Number Manufacturer Serial No. Date

Calibrated*

Calibration Certification

Number

Class 1 Integrating Real Time 1/3 Octave Sound Analyzer

Type 2260 Brϋel & Kjær 2467009 15/09/11 C1107367

Microphone Type 4189 Brϋel & Kjær 2508884 15/09/11 C1107367

Calibrator Type 4231 Brϋel & Kjær 2478249 04/09/12 01010/1

* Note that the calibration dates shown in Table 2 were correct at the time of the survey although the equipment

has undergone calibration since as part of an appropriate calibration schedule. Current and traceable calibration

certificates are available for all survey equipment.

6.1.3 Background and ambient noise monitoring was undertaken at the times specified in Table 5, below.

Measurement locations are shown in Figure 2.

Table 3: Dates, Times and Weather Conditions During Noise Measurements

Measurement Locations

Date Time Weather conditions

P1 – P4 26/06/13 05:21 – 09:00 Overcast, dry, 11°C and a light westerly breeze

with a speed of approximately 0 - 1 m/s.

6.1.4 The measurement locations are detailed below and indicated on Figure 2.

• P1 approximately 8 m from the nearside edge of Bacup Road




6.1.5 Measurements were taken at times considered to be representative of the daytime and night-time

periods during which the proposed residential accommodation would be subject to the highest levels

of ambient noise. Locations P2 to P4 were selected primarily as validation points for calibrating the

noise model.

6.1.6 Measurements were made under free-field conditions at a height of 1.2 m above the ground.



Figure 2: Measurement Locations

6.2 Monitoring Results

6.2.1 A summary of the measurement data is provided in Table 6 below with full data in Appendix 2. All

data are sound pressure levels in dB re 20 µPa.

Table 4: Summary of Noise Measurements 26th June 2013

Measurement Location

Start Time

Elapsed Time

(hr:min:sec)

LAeq,T (dB)

Overall LAFmax (dB)

95th% LAFmax,5min

(dB)

LAF10,T

(dB) LAF90,T

(dB)

P1 05:21 0:30:00 59.3 76.3 71.0 62.7 43.5

P1 05:53 0:30:00 60.9 78.2 72.0 64.3 45.3

P1 06:23 0:30:00 63.8 81.2 74.7 67.2 52.9

P1 06:55 0:30:00 65.5 79.3 - 68.5 57.2

P1 07:25 0:30:00 66.8 84.1 - 69.4 60.3

P1 07:55 0:15:00 65.9 78.3 - 68.5 59.6

P2 08:13 0:15:00 68.3 91.4 - 69.0 60.9

P3 08:30 0:15:00 60.6 76.7 - 62.9 55.6

P4 08:45 0:15:00 55.5 66.1 - 57.8 51.5

Note: 95th percentile LAFmax only calculated for night-time measurements



6.2.2 Each measurement period at location P1 consisted of sequential 10 second samples which allowed

the variation in noise level over time to be assessed. This data was used to determine a ‘typical’

LAFmax noise level and octave band spectrum based on the 95th percentile of individual 10 second

measurements which was subsequently utilised within the noise model.

6.2.3 The 10 second noise levels have not been presented in this report but are kept on file for future

reference.

6.2.4 A time history of night-time LAFmax,10second noise measurements (i.e. measurements taken prior to

07:00) at P1 are provided in Figure 3, below.

Figure 3: LAFmax,10second Time History at Location P1 (Night-time)

40.0

45.0

50.0

55.0

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95th% = 72.9 dB LAFmax,10second



7 Impact of Existing Road Traffic Noise Sources on the Development

7.1 Computer Modelling

7.1.1 Predictions of existing noise levels on the site have also been undertaken using the CadnaA noise

modelling package. Specific model parameters were applied as follows:

• Propagation of noise using algorithms within ISO 9613: 1993 Acoustics - Attenuation of sound

during propagation outdoors. Roads were modelled as line sources at a height of 0.5 m above

ground level and calibrated using spectral data measured during the survey;

• Default ground absorption G = 0.5 (roads modelled with G = 0.0)

• Ground attenuation: spectral all sources;

• No adverse meteorological effects;

• Two orders of reflection;

• Due to the relatively small size of the development, close proximity to the dominant noise source

and small change in overall height at the site, topographical data was not incorporated into the

model. It is considered that the influence of topography on noise propagation across the site is

minimal.

7.2 Validation of the Noise Model

7.2.1 Noise level receptor points were incorporated into the CadnaA model at the noise survey

measurement locations to calibrate the model using the measured LAeq and LAFmax noise levels.

7.2.2 Daytime LAeq noise levels were modelled using the log average of the consecutive measurements

between 07:00 and 09:00 as validation levels. Night-time LAeq levels were modelled using the log-

average levels measured between 05:20 and 07:00, thereby providing a ‘worst case’ scenario for

night-time. Modelled LAFmax levels were based on the 95th percentile LAFmax,10second levels measured

between approximately 05:20 and 07:00.

7.2.3 The modelled results agreed with the measured results to within around ± 0.5 dB LAeq and around

± 3 dB LAFmax.

7.3 Noise Model Predictions

7.3.1 Three scenarios were modelled using the master plan provided in Appendix 1: daytime LAeq noise

levels affecting the site, night-time LAeq noise levels and night-time LAFmax noise levels. Screen shots

from the noise model are provided in Appendix 3.



7.4 Internal Noise Levels Assessed to BS 8233 Criteria

7.4.1 It is proposed that noise from the development is controlled to 30 dB LAeq in bedrooms at night and

35 dB LAeq in habitable rooms during the day. This equates to the ‘good’ levels advised in BS 8233 for

night-time noise and ‘good’ to ‘reasonable’ levels for daytime noise (see Section 5.1). The proposed

upper limit for individual noise events such as vehicle pass-bys is an indoor level of 45 dB LAFmax.

These are in line with the criteria advised by Rossendale Borough Council. As discussed in Section

6.2, the level equivalent to the 95th percentile of measured LAFmax,10second values has been assumed

within the assessment to be representative of the typical LAFmax value.

7.4.2 In order to assess the potential glazing and ventilation specifications that may be required to control

noise into dwellings, noise ingress calculations were undertaken based on the methodology in

BS EN 12354-39. The following assumptions were made regarding the internal rooms:

• Assessed within first floor bedrooms with an internal volume of 30 m3

• 'Normal' internal surface finishes e.g. carpeted with curtains etc

• Glazed area of 1.5 m2 per room.

7.4.3 Internal noise levels were predicted based on the night-time noise levels measured between 05:20

and 07:00 when noise from Bacup Road was dominant and increasing as the morning rush hour

approached. When averaged over a typical 8 hr period, night-time noise levels would be expected to

be lower. Nevertheless, it is considered reasonable to assess night-time noise during this period as

traffic starts to build but residents are still likely to be sleeping.

7.4.4 Calculations have indicated that internal noise within bedrooms at night may be controlled to the

criteria levels in 7.4.1 by the selection of appropriate glazing configurations and trickle ventilators. The

noise model also indicates that the majority of dwellings will be able to achieve the night-time noise

criteria with windows open for ventilation. However, there are several dwellings within closest

proximity to Bacup Road that are likely to require an alternative means of ventilation that obviates the

need to open windows.

7.4.5 Recommendations for glazing and ventilation options are discussed in Section 8.

7.5 External Noise Levels

7.5.1 The noise model indicated that much of the site will benefit from acoustic shielding provided by the

buildings located at the southern boundary of the site. However, there are two areas where gaps

between buildings result in insufficient shielding of noise from Bacup Road. It is recommended that

acoustic fencing is provided as described in Section 8.7. With the provision of these fences, the

9 BS EN 12354-3:2000 Building acoustics. Estimation of acoustic performance in buildings from the performance of

elements - Airborne sound insulation against outdoor sound



daytime limit of 55 dB LAeq is predicted to be met in all gardens with many also achieving the preferred

lower level of 50 dB LAeq. Screenshots from the noise model in Appendix 3 illustrate the attenuation

provided by the proposed fencing between plots 20 and 21 and between plot 27 and its adjacent

garage. Recommended mitigation measures are discussed in more detail in Section 8.

8 Recommended Mitigation Measures

8.1 Building Envelope Construction

8.1.1 The necessary mitigation to the building envelope, i.e. glazing, trickle ventilation and ceiling

construction on the top floor, will depend on the proximity of the dwelling to Bacup Road and its

orientation. Dwellings subject to the highest noise levels will need the highest specification and may

also require some form of assisted ventilation which obviates the need to open windows to provide

rapid ventilation or comfort cooling in summer.

8.1.2 The generally accepted rule of thumb is that a window left open for ventilation provides 10 - 15 dB

attenuation from external noise sources with the WHO Guidelines for Community Noise suggesting

15 dB. The DEFRA report NANR116: Open/Closed Window Research10 suggests the figure to be

between 12 and 18 dB for road and rail traffic. Therefore, where external noise levels are more than

around 15 dB higher than the internal noise targets, openable windows should not be relied upon as

the sole means of ventilation and some form of acoustically attenuated ventilation may be required.

8.1.3 Note that external walls formed from standard cavity masonry constructions with minimum 100 mm

brick or blockwork leaves will provide sufficient levels of sound insulation in all cases. If other

construcitons are to be considered, it is recommended that an overall sound insulation rating of at

least 48 dB Rw + Ctr is achievbed by the solid wall element.

8.1.4 An example noise ingress calculation sheet is provided in Appendix 4 with other calculation sheets

kept on file.

8.1.5 The following recommended mitigation measures are based on the masterplan current at the time of

writing (as shown in Appendix 1). Any significant changes to the layout and orientation of proposed

dwellings would necessitate a re-evaluation of the proposed specifications.

8.2 Specification 1: Plots 21 to 27 inclusive

8.2.1 The habitable rooms of plots 21 to 27 facing Bacup Road are subject to the highest levels of noise

and therefore need the highest specifications for glazing and ventilation. This is summarised as

follows:

10 NANR116: ‘Open/closed window research’ Sound Insulation through ventilated open windows, Defra April 2007



• Acoustic double glazed unit with minimum sound insulation rating of 35 dB Rw + Ctr. This

could be achieved with glazing with a 10/12/6.4 (laminated) configuration.

• No trickle ventilation – all background ventilation to be provided by mechanical ventilation

system with supply air taken from the rear (north facing) elevation. Although openable

windows may be provided for use at the discretion of the occupant, means must be provided

to ventilate habitable rooms that do not require ventilation openings on the Bacup Road

facade. A whole-house ventilation system with a ‘boost’ option capable of providing ventilation

at purge rates, e.g. for rapid ventilation or summer cooling, would be suitable in this regard.

• Ceilings of habitable rooms on the top floor or in the roof space are to be enhanced such that

2 layers of plasterboard are utilised within the construction with a minimum 100 mm of mineral

wool insulation (minimum density 10 kg/m3) in the void between ceiling and roof.

8.3 Specification 2: Plots 19 and 20

8.3.1 The habitable rooms located on both front and rear elevations of plots 19 and 20 are subject to the

next highest levels of noise and the following minimum specification is recommended:

• Acoustic double glazed unit with minimum sound insulation rating of 33 dB Rw + Ctr. This

could be achieved with glazing with a 10/12/6 configuration.

• Background ventilation provided by acoustic trickle ventilators with a minimum element

normalised level difference of 41 dB Dne,w.

• Noise levels are likely to be too high to rely on openable windows for rapid ventilation or

summer cooling and an alternative ventilation scenario should be adopted for habitable

rooms. Either an attenuated mechanical ventilation system or a whole-house ventilation

system with a ‘boost’ option would be suitable in this regard.




8.4 Specification 3: Plots 17 and 18

8.4.1 The habitable rooms located on both front and rear elevations of plots 17 and 18 are subject to lower

levels of noise and the following minimum specification is recommended:

• Double glazed unit with minimum sound insulation rating of 29 dB Rw + Ctr. This could be

achieved with glazing with a 6/12/6 configuration.



• Noise levels are likely to be too high to rely on openable windows for rapid ventilation or

summer cooling and an alternative ventilation scenario should be adopted for habitable



rooms. Either an attenuated mechanical ventilation system or a whole-house ventilation

system with a ‘boost’ option would be suitable in this regard.




8.5 Specification 4: Plots 11 to 16 (south facing facades)

8.5.1 The habitable rooms located on south facing elevations of plots 11 to 16 are subject to lower levels of

noise and the following minimum specification is recommended:


achieved with standard thermal double glazing with a 4/20/4 configuration.



• Openable windows should be adequate for rapid ventilation and summer cooling.

• No special requirements for ceilings to habitable rooms on the top floor.

8.6 Specification 5: Plots 1 to 10, plus 28 and 29 (and north facing facades)

8.6.1 The habitable rooms located on south facing elevations of plots 1 to 10, east and west facing facades

of plots 28 and 29, plus all other north facing elevations are subject to the lowest levels of noise and

the following minimum specification is recommended:


achieved with standard thermal double glazing with a 4/20/4 configuration.

• Background ventilation provided by hit-and-miss trickle ventilators.

• Openable windows should be adequate for rapid ventilation and summer cooling.

• No special requirements for ceilings to habitable rooms on the top floor.

8.7 Acoustic barrier between plots 20 and 21, and to eastern site boundary adjacent to plot 27

8.7.1 It is recommended that a permanent acoustic fence or solid wall is erected between plots 20 and 21

such that a minimum height of 2 m is maintained. A second barrier is also recommended at the site’s

eastern boundary between plot 27 and the garage of plot 27. The effect of the barriers is

demonstrated in the noise model shown in Appendix 3 with the locations indicated in Figure A5. The

noise contours are shown in 5 dB bands with the grey coloured band indicating the preferred level of



50 to 55 dB LAeq and the yellow coloured contour band indicating 45 to 50 dB LAeq. It can be seen that

with the barriers, all rear gardens are predicted to satisfy the requirement.

8.7.2 Current proposals are for a masonry wall between plots 20 and 21 although timber fencing would

suffice if necessary. Any timber fencing should be formed from material with a minimum mass of

12 kg/m2 and is to extend from the ground to a minimum height of 2.0 m. There should be no gaps

between panels. Overlapped or tightly butted boards or panels would be suitable in this respect; hit-

and-miss panelling would not.

9 Conclusions

9.1 Miller Goodall Environmental Services has undertaken an assessment of the impact of road traffic

noise on a proposed residential development site located on Bacup Road in Rawtenstall to support a

planning application.

9.2 Noise measurements were made of the existing noise climate affecting the site which was dominated

by road traffic on Bacup Road. This data was used to populate a noise model of the site which was

subsequently utilised to predict the likely external noise levels and internal noise levels within proposed

dwellings.

9.3 Based on the findings from the noise model, it is predicted that the internal noise level criteria can be

achieved with the selection of appropriate glazing, ceiling and ventilation solutions. Recommended

specifications have been provided for different plots based on their proximity to Bacup Road.

9.4 With the provision of an appropriate noise barrier between plots 20 and 21 and to the eastern site

boundary near to plot 27, external noise levels in gardens are predicted to satisfy recognised criteria.

9.5 In conclusion, we see no reason why planning permission for this development should be refused on

the grounds of noise.



Glossary of Terms

Decibel (dB) The unit used to quantify sound pressure levels; it is derived from the logarithm of the ratio

between the value of a quantity and a reference value. It is used to describe the level of many

different quantities. For sound pressure level the reference quantity is 20 µPa, the threshold of

normal hearing is in the region of 0 dB, and 140 dB is the threshold of pain. A change of 1 dB is

usually only perceptible under controlled conditions.

dB LA Decibels measured on a sound level meter incorporating a frequency weighting (A weighting)

which differentiates between sounds of different frequency (pitch) in a similar way to the human

ear. Measurements in dB LA broadly agree with an individual’s assessment of loudness. A

change of 3 dB LA is the minimum perceptible under normal conditions, and a change of 10 dB

LA corresponds roughly to halving or doubling the loudness of a sound. The background noise

level in a living room may be about 30 dB LA; normal conversation about 60 dB LA at 1 meter;

heavy road traffic about 80 dB LA at 10 meters; the level near a pneumatic drill about 100 dB LA.

LA90,T The A weighted noise level exceeded for 90% of the specified measurement period (T). In BS

4142: 1997 it is used to define background noise level.

LAeq,T The equivalent continuous sound level. The sound level of a notionally steady sound having

the same energy as a fluctuating sound over a specified measurement period (T). LAeq,T is used

to describe many types of noise and can be measured directly with an integrating sound level

meter.

LAmax The highest A weighted noise level recorded during the time period. It is usually used to

describe the highest noise level that occurred during the event.

NOEL No observed effect level: the level of noise exposure below which no effect at all on health or

quality of life can be detected.

LOAEL Lowest observed adverse effect level: the level of noise exposure above which adverse effects

on health or quality of life can be detected.

SOAEL Significant observed adverse effect level: the level of noise exposure above which significant

adverse effects on health or quality of life can be detected.

Rw Single number rating used to describe the sound insulation of building elements and is defined

in BSEN ISO 140-3: 1995. It is derived by measurement under laboratory conditions and does

not take into account the effects of flanking transmissions.

Dne,w The weighted element-normalized level difference is a single figure rating used to describe the

sound insulation of small elements within a larger construction and is defined in BSEN ISO 140-

10: 1991. It is most often used to rate the sound insulation performance of ventilator units e.g.

trickle vents.

Ctr A spectrum adaptation term used to characterise the sound insulation rating with respect to

urban traffic.



Appendix 1a: Masterplan of Whinberry View Site



Appendix 1b: Proposed House Types



Appendix 2: Measurement Results

Location Start Time

Elapsed Time

(hr:min:sec)

LAeq,T (dB)

Overall LAFmax (dB)

95th% LAFmax,

5min (dB)

LAF1,T

(dB) LAF10,T

(dB) LAF90,T

(dB) LAF99,T

(dB) LAFmin

(dB)

P1 05:21 0:30:00 59.3 76.3 71.0 70.0 62.7 43.5 39.8 36.8

P1 05:53 0:30:00 60.9 78.2 72.0 71.0 64.3 45.3 40.8 37.9

P1 06:23 0:30:00 63.8 81.2 74.7 72.7 67.2 52.9 46.9 44.4

P1 06:55 0:30:00 65.5 79.3 - 74.2 68.5 57.2 50.9 46.7

P1 07:25 0:30:00 66.8 84.1 - 75.3 69.4 60.3 56.5 50.8

P1 07:55 0:15:00 65.9 78.3 - 74.1 68.5 59.6 54.1 51.4

P2 08:13 0:15:00 68.3 91.4 - 76.6 69.0 60.9 57.1 54.0

P3 08:30 0:15:00 60.6 76.7 - 67.6 62.9 55.6 50.6 48.3

P4 08:45 0:15:00 55.5 66.1 - 63.2 57.8 51.5 47.0 45.0



Appendix 3: Screenshots from CadnaA Noise Model



Figure A1: Daytime LAeq Noise Levels (with acoustic barriers)



Figure A2: Night-time LAeq Noise Levels (with acoustic barriers)



Figure A3: Night-time LAmax Noise Levels (with acoustic barriers)



Figure A4: Location of Proposed Noise Barriers

Proposed barriers minimum 2.0 m high



Appendix 4: Example Noise Ingress Calculation



Part 2: Roof/ceiling only

Description Term Value

Total facade area (m2) Sf 0 Leave blank - assessed in Part 1

Window area (m2) Swi 0 Leave blank - assessed in Part 1

External wall area (Sf - Swi) Sew 0

Area of ceiling (m2) Srr 12 Enter ceiling area here

Total area of elements (Sf + Srr) S 12

Volume of receiving room (m3) V 30

Reference absorption area (m2) A0 10

Number of ventilators in roof: 0 If applicable

Angle of incidence (degrees): θ 60

63 125 250 500 1k 2k 4k 8k dBA Rw Ctr

Rw+

Ctr Notes

External Leq, freefield (dB Leq,ff) 68 63 60 56 58 55 47 37 62 - - - Freefield daytime level

External Lmax, freefield (dB Lmax,ff) 81 75 71 67 69 66 58 49 73 - - - 95th% Freefield night-time level

Dne of each ventilator 27 31 33 42 43 39 44 44 41 -3 38 Renson AK38 acoustic trickle vent

Total Dne of all ventilators #### #### #### #### #### #### #### #### - ##### ##### #####

SRI of window (Rwi)

SRI of external wall (Rew)

SRI of roof and ceiling (Rrr) 21 27 37 43 48 52 52 52 46 -7 39 Tiled/slate roof, 25 mm plasterboard ceiling, 100 mm mineral wool insulation

Rev time of receiving room (T) - secs 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Habitable room ref Part E

All ventilators [eqn. B] #### #### #### #### #### #### #### #### A0/S x 10^(-Dne/10)

Glazing [eqn. C] 0 0 0 0 0 0 0 0 Swi/S x 10^(-Rwi/10)

External wall [eqn. D] 0 0 0 0 0 0 0 0 Sew/S x 10^(-Rew/10)

Ceiling [eqn. E] 0.01 0 0 0 0 0 0 0 Srr/S x 10^(-Rrr/10)

All ventilators [10 x log "B"] #### #### #### #### #### #### #### ####

Glazing [10 x log "C"] #### #### #### #### #### #### #### ####

External wall [10 x log "D"] #### #### #### #### #### #### #### ####

Ceiling [10 x log "E"] -21.0 -27.0 -37.0 -43.0 -48.0 -52.0 -52.0 -52.0

All elements combined [eqn. F] -21.0 -27.0 -37.0 -43.0 -48.0 -52.0 -52.0 -52.0 Log sum of equations B,C,D,E

Equiv. absorption area of rec. room (m2

10 10 10 10 10 10 10 10

10 x log(S/A) [eqn. G] 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

10 x log(cos θ) [eqn. H] -3.0 -3.0 -3.0 -3.0 -3.0 -3.0 -3.0 -3.0 Maximum correction -6 dB

Via roof only 63 125 250 500 1k 2k 4k 8k dBA Target Exc.

Internal Leq,2 51 40 27 17 14 7 -1 -11 28 30 -2 Equations (A+F+G+H) +6 dB

Internal Lmax,2 64 52 38 28 25 18 10 1 41 45 -4 Equations (A'+F+G+H) +6 dB

A-weighted spectra

A-weightings: -26 -16 -9 -3 0 1 1 -1 dBA Target Exc.

Internal LAeq,2 25 24 18 14 14 8 0 -12 28 30 -2

Internal LAmax,2 38 36 29 25 25 19 11 0 41 45 -4

Total for Facade and Roof Combined 63 125 250 500 1k 2k 4k 8k dBA Target Exc.

Internal Leq,2 52 41 32 21 18 13 0 -10 30 30 0

Internal Lmax,2 65 53 43 32 29 24 11 2 42 45 -3

Octave band centre frequency, Hz

NOISE ASSESSMENT HOURIGAN CONNOLLY WHINBERRY VIEW, …

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