31 July 2013

1 Introduction 1
2 Legislation and Guidance
2.1
National Policy
2.2
Planning Policy Guidance (PPG) 24: Planning and Noise
3
3
4
3 Noise Survey 5
3.1
Noise Monitoring Locations 5
3.2
Instrumentation 6
3.3
Weather Conditions
3.4
Dominant Noise Sources
6
6
4 Results and PPG 24 Assessment
4.1
Baseline Noise Assessment
4.2
PPG 24 Noise Assessment
5 Conclusions and Possible Mitigation Measures 9
5.1
Conclusions 9
5.2
Possible Mitigation Measures
Appendix A   Definitions
Appendix B   Proposed Housing Development Layout - Option B
Appendix C   Noise Monitoring Location Plan
Appendix D   Calibration Certificates
9
7
7
8

Jacobs have been commissioned by Coventry City Council (CCC) to undertake a noise assessment at a potential residential development site on Broad Lane,
Coventry, at its junction with Jardine Crescent.
It is understood that the noise assessment will inform an outline planning application, at this stage, and that a more robust assessment will be undertaken at detailed design stage i.e. when the layout is proposed.
The Hawthorn Lodge Elderly people’s care home building, which formerly occupied the site proposed development site, has been demolished prior to the noise monitoring survey taking place.
To aid the understanding of this report, Appendix A provides definitions of some of the terms used.
At the time of this noise assessment being undertaken, the favoured indicative housing development option was Option B. Housing development Option B is provided within Appendix B of this report. Subsequently a slightly revised indicative layout has been provided, with one less unit, but it is considered that the change will not significantly alter the findings or recommendations of this report.
1

2

2.1.1 National Planning Policy Framework (Department for Communities and
Local Government, 2011)
The NPPF came into force in March 2012, and in doing so has resulted in the withdrawal of Planning Policy Guidance (PPG) 24 - Planning and Noise, a document which had previously given technical guidance on the assessment of noise when considering planning issues.
Section 11 ‘Conserving and enhancing the natural environment’, advises that the planning system should contribute to and enhance the natural and local environment by:

Preventing both new and existing development from contributing to or being put at an unacceptable risk from, or being adversely affected by unacceptable levels of soil, air, water or noise pollution or land instability.
With regard to Planning Policies and Decisions these should aim to:

Avoid noise 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 through the 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 nearby land uses since they were established.

Identify and protect areas of tranquillity that have remained relatively undisturbed by noise and are prized for their recreational and amenity value for this reason.
2.1.2 Noise Policy Statement for England (DEFRA, 2010)
This document includes the Policy Statement and an Explanatory Note. The Noise
Policy aims are that through the effective management and control of environmental, neighbour and neighbourhood noise within the context of Government policy on sustainable development:

“Avoid significant adverse impacts on health and quality of life;

Mitigate and minimise adverse impacts on health and quality of life; and

Where possible, contribute to the improvement of health and quality of life.”
Paragraph 2.3 of the Explanatory Note details:

“Furthermore, the broad aim of noise management has been to separate noise sources from sensitive noise receivers and to “minimise” noise. Of course, taken in isolation and to a literal extreme, noise minimisation would mean no noise at all. In reality, although it has not always been stated, the aim has tended to be to minimise noise “as far as reasonably practical”. This concept can be found in the Environmental Protection Act 1990, where in some
3

circumstances, there is a defence of “best practicable means” in summary statutory nuisance proceedings.”
Although PPG 24 has now been withdrawn and has been superseded by the NPPF, it did set out the Government’s policies on noise and gave advice to local authorities on the use of their powers to minimise the adverse impact of noise. It also outlined the considerations that local planning authorities needed to take into account when determining planning applications for new noise sensitive development.
Despite the withdrawal of PPG 24, it has been agreed with Neil Chaplin,
Environmental Protection Officer at Coventry CC, that it would be appropriate that the guidance contained within PPG 24 is applied when assessing the suitability of the proposed residential development site.
PPG 24 introduced the concept of noise exposure categories (NEC’s) for residential development, as shown in Table 2-A, and recommended appropriate levels for exposure to various noise sources. NEC A represented the circumstances in which noise is unlikely to be a determining factor for planning permission, while NEC D related to the situation in which development should normally be refused.
Noise Exposure
Category
A
B
C
D
Noise need not be considered as a determining factor in granting planning permission, although the noise level at the high end of the category should not be regarded as a desirable level
Noise should be taken into account when determining planning applications and, where appropriate, conditions imposed to ensure an adequate level of protection against noise
Planning permission should not normally be granted. Where it is considered that permission should be given, for example because there are no alternative quieter sites available, conditions should be imposed to ensure a commensurate level of protection against noise
Planning permission should normally be refused
Table 2-A PPG 24 Noise Exposure Categories
PPG 24 recommended a range of acceptable noise levels for each of the above
NEC’s for dwellings exposed to road, rail, and aircraft noise and noise from mixed sources. Based on the notes recorded during the noise survey (see chapter 3), the proposed development site is considered to be largely dominated by road traffic, for which the relevant noise exposure category levels are provided in Table 2-B.
Noise Levels corresponding to the Noise Exposure Categories for New Dwellings, LAeq,T
(dB) (free-field noise levels)
Hours
A
Noise Exposure Category
B C D
07:00 to 23:00
23:00 to 07:00
<55
<45
55-63
45-57
63-72
57-66
>72
>66
Table 2-B Recommended NECs and associated noise levels for new dwellings proposed in areas where the noise climate is dominated by ‘road traffic noise’
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The baseline noise survey was undertaken between 10:00 and 13:00 on
Wednesday 19 June 2013.
The noise monitoring survey consisted of continuous monitoring at three locations, representative of façade locations of the nearest properties shown on the proposed layout drawing (Appendix B). The meters were attended at all times and a log of the dominant noise sources noted throughout the survey was made.
The noise climate was anticipated to be heavily dominated by traffic noise, and as such a noise monitoring strategy following the shortened measurement procedure, as detailed within the Calculation of Road Traffic Noise (HMSO, 1988) (CRTN) was adopted. The CRTN provides a method for converting between the noise level measured during the shortened measurement procedure, L
A10,3-hour
, to L
A10,18-hour noise level through a 1 dB subtraction.
The derived L
A10,18-hour
noise level can then be converted to a L
Aeq,16-hour
noise level through a 2 dB subtraction, as detailed within PPG 24. This then allows for a comparison against the NEC noise criteria levels detailed with PPG 24.
The derived L
A10,18-hour
noise level can then be converted to an L night
noise level using the calculation shown below (applicable to non-motorway roads), which is taken from the Transport Research Laboratory (TRL) document ‘Converting the UK traffic noise index L
A10,18-hour
to EU noise indices for noise mapping’ (PR/SE/451/02).
Two of the locations used during the baseline noise assessment were at the northern edge of the proposed development, while the third was on the southwestern edge of the site. The monitoring locations were selected as they were considered to represent the facades of the proposed dwellings that are likely to be most significantly impacted by road traffic noise. The locations have been referred to as locations A, B and C, as described below.
Location A North-west corner of the development site, located at the position of the northern façade of the proposed dwelling at the north-west corner of the residential development. This monitoring location is approximately 28 metres south of Broad Lane and 16 metres east of
Jardine Crescent.
Location B North-east corner of the development site, located at the position of the northern façade of the proposed dwelling at the north-east corner of the residential development. This monitoring location is approximately 21 metres south of Broad Lane.
Location C South-west corner of the development site, located at the position of the southern façade of the proposed dwelling at the south-west corner of the residential development. This monitoring location is approximately 20 metres east of Jardine Crescent.
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The noise monitoring locations are illustrated in Appendix C.
For other locations within the site, further from the roads, noise levels would be lower than reported for these three locations.
Measurements were undertaken using Type 1 precision grade instrumentation.
Three Cirrus Optimus Green Type CR:171C real-time frequency analysers, calibrated using Model 105 acoustic calibrators, were used for the survey.
The instruments were located in free-field positions (at the proposed locations of nearest residential dwellings to the nearby roads) with the microphone at a height of approximately 1.5 m above ground level Measurements were undertaken with due regard to BS 7445 ‘Description and Measurement of Environmental Noise’, Part 1:
2003.
The data collected included L
Aeq
, L
A90
, L
A10
, L
A1
and single octave band L eq
levels.
The calibration certificates for the equipment used during this assessment are provided in Appendix D.
Monitoring
Location
Sound Level Meter Type Sound Level Meter Serial Number
A Cirrus CR171C SLM G061729
B
C
Cirrus CR171C SLM
Cirrus CR171C SLM
G061732
G061733
Table 3-A Sound level meters used during baseline noise survey
3.2.1 Calibration
The sound level meters were calibrated at the start of each monitoring period and checked at the end. No significant variations in calibration were noted.
At the start of the noise survey the weather was noted as being dry and cloudy, with a very light breeze. The weather remained dry, turning sunny later, with calm conditions by the end of the survey.
The weather conditions during this baseline noise assessment were considered suitable for noise monitoring.
The dominant noise source noted throughout the survey was road traffic noise, including idling vehicles and the movement of occasional large vehicles, such as buses and a refuse wagon. Additional contributions from birdsong and occasional overhead aircraft were also noted.
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The noise monitoring results gathered at each of the three monitoring locations are presented in Tables 3-A to 3-C, below.
Date Start Time End Time
Duration
(mins)
L
Aeq
L
Amax
L
A10
L
A90
19/06/2013 10:00 11:00 60 55 68 58 49
19/06/2013 11:00 12:00 60 55 76 57 48
19/06/2013 12:00 13:00 60 54 70 57 48
Average 10:00 13:00 180 55 68 57 48
Table 4-A Baseline noise monitoring data, Broad Lane (Coventry) – Location A
An arithmetic average L
A10,3-hour
noise level of 57 dB has been measured at
Location A, which equates to an L
A10,18-hour
noise level of 56 dB (CRTN, para.43) and a L
Aeq,16-hour
noise level of 54 dB (PPG 24, Annex 1, para.9).
A L night
noise level of 47 dB has been calculated from the derived L
A10,18-hour
noise level (TRL, PR/SE/451/02, page 29).
Date Start Time End Time
Duration
(mins)
L
Aeq
L
Amax
L
A10
L
A90
19/06/2013 10:00 11:00 60 58 71 61 51
19/06/2013 11:00 12:00 60 58 78 60 51
19/06/2013 12:00 13:00 60 57 74 60 50
Average 10:00 13:00 180 58 71 60 51
Table 4-B Baseline noise monitoring data, Broad Lane (Coventry) – Location B
An arithmetic average L
A10,3-hour
noise level of 60 dB has been measured at
Location B, which equates to an L
A10,18-hour
noise level of 59 dB (CRTN, para.43) and a L
Aeq,16-hour
noise level of 57 dB (PPG 24, Annex 1, para.9).
A L night
noise level of 49 dB has been calculated from the derived L
A10,18-hour
noise level (TRL, PR/SE/451/02, page 29).
Date Start Time End Time
Duration
(mins)
L
Aeq
L
Amax
L
A10
L
A90
19/06/2013 10:00 11:00 34 53 67 56 47
19/06/2013
19/06/2013
Average
11:00 12:00 60 52 71 55 46
12:00 13:00 60 52 68 55 45
10:00 13:00 180 52 69 55 46
Note: 10:00 to 10:26 – significant noise impact from construction noise (workmen using strimmer / lawnmower and a generator) removed from noise data shown above.
Table 4-C Baseline noise monitoring data, Broad Lane (Coventry) – Location C
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An arithmetic average L
A10,3-hour
noise level of 55 dB has been measured at
Location C, which equates to a L
A10,18-hour
noise level of 54 dB (CRTN, para.43) and an L
Aeq,16-hour
noise level of 52 dB (PPG 24, Annex 1, para.9).
A L night
noise level of 45 dB has been calculated from the derived L
A10,18-hour
noise level (TRL, PR/SE/451/02, page 29).
Based on the measured baseline noise levels, L
Aeq,16-hour
noise levels of 52, 54 and
57 dB have been derived.
Two of the monitoring locations (locations A and C) fall in to PPG 24 NEC Category
A, which advises the following:

Noise need not be considered as a determining factor in granting planning permission, although the noise level at the high end of the category should not be regarded as a desirable level.
Monitoring location B, which is located towards the north-east of proposed development (21 metres south of Broad Lane), falls in to PPG 24 NEC Category B, which advises the following:

Noise should be taken into account when determining planning applications and, where appropriate, conditions imposed to ensure an adequate level of protection against noise.
For other locations within the site, further from the roads, noise levels would be lower than reported for these three locations. It is likely that they would fall within
NEC A.
Based on the measured baseline noise levels, L night
noise levels of 45, 47 and 49 dB have been derived
As such, all three of the monitoring locations fall in to PPG 24 NEC Category B, which advises the following:

Noise should be taken into account when determining planning applications and, where appropriate, conditions imposed to ensure an adequate level of protection against noise.
For other locations within the site, further from the roads, noise levels would be lower than reported for these three locations. It is likely that they would fall within
NEC A to NEC B.
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The noise assessment undertaken at the Broad Lane proposed housing development site has shown that:

During daytime hours, two of the three noise monitoring locations (A and C) selected to represent the facades of the properties, fall into PPG 24 NEC A
(where noise need not be considered as a determining factor in granting planning permission);

The third noise monitoring location (B) falls into PPG 24 NEC B (where noise should be taken into account when determining planning applications and, where appropriate, conditions imposed to ensure an adequate level of protection against noise);

At night, all of the noise monitoring locations fall into PPG 24 NEC B (where noise should be taken into account when determining planning applications and, where appropriate, conditions imposed to ensure an adequate level of protection against noise).
As such, noise mitigation measures should be considered when the final layout for development is being designed, in order to ensure a suitable residential environment for proposed properties. Proposed mitigation measures are likely to be for the benefit of properties closest to Broad Lane and Jardine Crescent only. Based on the indicative layout provided, proposed residential dwellings within the inner parts of the site are unlikely to require specific noise mitigation, as the outer properties are likely to provide noise screening to the inner parts of the site.
During detailed design for the site, consideration will need to be given to mitigation measures available to reduce the potential noise impacts on the properties closest to Broad Lane and Jardine Crescent. Some mitigation measures that could be considered during detailed design include:

Provide screening fences / walls around the perimeter of the site and / or garden areas to protect amenity. Solid walls / barriers should consist of a material with a surface density greater than 10 kg/m
2
, and contain no gaps in their construction;

Locating residential buildings further from Broad Lane and Jardine Crescent
(creating a wider buffer zone adjacent to roads);

Position the least sensitive (non-habitable) rooms within the residential properties towards Broad Lane and Jardine Crescent, such as kitchens, bathrooms, staircases, etc. Ensure living areas and bedroom areas are orientated away from Broad Lane and Jardine Crescent.
Based on a review of the indicative layout provided, a potential noise mitigation strategy could involve the installation of timber reflective noise fencing to the garden
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boundaries facing towards Broad Lane, in combination with a lower height brick wall or timber fencing close to the footpaths adjacent to Broad Lane and Jardine
Crescent.
Detailed noise predictions would need to be undertaken during detailed design to accurately identify appropriate mitigation measures, the above guidance is considered indicative only.
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The sound wave travelling through the air is a regular disturbance in ambient atmospheric pressure. These pressure fluctuations, when of frequencies within the audible range, are detected by the human ear which passes nerve responses to the brain, producing the sensation of hearing. Noise has been defined in a variety of ways and is very much dependant on factors such as the listener’s attitude to the source of the sound and their environment, but is essentially any sound that is unwanted by the recipient.
It is impossible to measure the degree of nuisance caused by noise directly, as this is essentially a subjective response of the listener, but it is possible to measure the
“loudness” of that noise. Loudness is related to both the sound pressure (the magnitude of the maximum excursion of the pressure wave around the ambient atmospheric pressure) and the frequency, both of which can be measured.
The human ear is sensitive to a wide range of sound levels; the sound pressure level of the threshold of pain is over a million times that of the quietest audible sound. In order to reduce the relative magnitude of the numbers involved, a logarithmic scale of decibels (dB) based on a reference level of the lowest audible sound is used.
Also, the response of the human ear is not constant over all frequencies. It is therefore usual to weight the measured frequency to approximate human response.
This is achieved by using filters to vary the contribution of different frequencies to the measured level. The “A” weighting network is the most commonly used and has been shown to correlate closely to the non-linear and subjective response of humans to sound. The use of this weighting is denoted by a capital A in the unit abbreviation (i.e. L
Amax
, L
Aeq
, L
A90
etc.) or a capital A in brackets after a dB level (i.e.
3 dB(A)).
Sound Pressure Level: The sound pressure level (L
P
or SPL) is the instantaneous acoustic pressure and is measured in decibels (dB). Since the ear is sensitive to variations in pressure, rather than source power or intensity, the measurement of this parameter gives an indication of the impact on people. The
SPL is defined as:
SPL

10 log
10

 p p
2
2 ref

 or SPL

20 log
10

 p p ref


Where p is the rms pressure of the sound (in pascals (Pa)) and sound pressure, defined as the limit of human audibility (2 x 10 p ref
is the reference
-5
Pa)
Sound Power Level: The sound power level (L
W
or PWL) is a measure of the acoustic energy output of a source and is a property of the source itself. The
PWL is also measured in dB and is given by:
PWL

10 log
10


W
W
0


Where W is the sound power of the source (in watts) and W
0
is the reference sound power (10
-12
watts).

L eq
: L eq
is defined as the equivalent continuous sound level and is the most widely used parameter for assessing environmental noise. Since this descriptor is a type of average level, it must by definition have an associated time period over which the measurement is referring to. This is often included in the abbreviation in the form L eq, T
, where T is the time period (i.e. L
Aeq, 5 min
). The formula for calculating the L eq
is:
L eq

10 log
10

 t
2
1
 t
1
 t t
1
2 p 2 p 2 ref
.
dt


In practice, since most modern sound level meters are digital and hence take periodic samples of the sound pressure level, the L eq
will be the logarithmic average of all the SPL samples taken in the measurement period.
L max :
The max
is defined as the maximum rms level recorded during a measurement period.
L n
: L n
is a statistical descriptor and refers to the level that is exceeded for n% of the time during a particular measurement period. Again, the measurement period that the descriptor refers to is often included in the abbreviation in the format
L n, T
. Two of the most commonly used statistical descriptors used for environmental noise assessments are the L
90
and the L
10
. These are described in more detail below.
L
10
: L
10
refers to the level exceeded for 10% of the measurement period and is commonly used in assessing road traffic noise as it has been found to give a good indication of the subjective human response to this type of noise.
L
90
: L
90
refers to the level exceeded for 90% of the measurement period and is widely considered to represent background noise, or the underlying noise in an area between noisy events (such as cars passing etc.).
Free-Field: The term “free-field” refers to noise levels that have been measured or predicted in the absence of any influence of reflections from nearby surfaces. In practice, a measurement is considered to be free-field if it was taken at a distance of over 3.5 m from any reflecting surfaces.
Façade Level: Façade levels refer to levels taken at a distance of between 1 and 3.5 m of the façade of a building. The difference between the façade and freefield level will depend on the distance from the reflecting surface, but is generally accepted to be approximately 2.5 dB(A).