Robertstown Development

Robertstown Development

Noise planning report

For Rhondda Cynon Taf County Borough

Council

Date: 13 July 2018

Doc ref: ROB-HYD-XX-ZZ-RP-Y-0001

HYDROCK TECHNICAL REPORT | Rhondda Cynon Taf County Borough Council | Robertstown Development | ROB-HYD-XX-ZZ-RP-Y-0001 | 13 July 2018 i

DOCUMENT CONTROL SHEET

Issued by Hydrock Consultants Limited Over Court Barns Over Lane Almondsbury Bristol BS32 4DF

Tel: 01454 619533 Fax: 01454 614125 www.hydrock.com

Client Rhondda Cynon Taf County Borough Council

Project name Robertstown Development

Title Noise planning report

Doc ref ROB-HYD-XX-ZZ-RP-Y-0001

Project no. C-08918-C

Status Issued

Date 13/07/2018

Document Production Record

Issue Number 01 Name

Prepared by Jeremie Dufaud

Checked by Ric Hampton

Approved by Ric Hampton

Document Revision Record

Issue Number Status Date Revision Details

01 For Issue 13/07/2018 First issue

Hydrock Consultants Limited has prepared this report in accordance with the instructions of the above-named

client for their sole and specific use. Any third parties who may use the information contained herein do so at

their own risk.

HYDROCK TECHNICAL REPORT | Rhondda Cynon Taf County Borough Council | Robertstown Development | ROB-HYD-XX-ZZ-RP-Y-0001 | 13 July 2018 ii

CONTENTS

NOISE PLANNING REPORT........................................................................................................................................ 1

Robertstown Industrial Development ...................................................................................................................... 1

1. INTRODUCTION ........................................................................................................................................... 1

2. DESCRIPTION - DEVELOPMENT SITE ........................................................................................................... 2

3. PLANNING POLICY WALES ........................................................................................................................... 3

3.1 Edition 9 Chapter 13 ................................................................................................................................... 3

3.2 Local policy ................................................................................................................................................. 3

4. GUIDANCE DOCUMENTS ............................................................................................................................ 5

4.1 British Standard 8233:2014 ........................................................................................................................ 5

4.2 British Standard 4142:2014 ........................................................................................................................ 5

4.3 Calculation of Road Traffic Noise ................................................................................................................ 6

5. NOISE SURVEY ............................................................................................................................................. 7

5.1 Methodology .............................................................................................................................................. 7

5.2 Environmental Noise Monitoring ................................................................................................................ 7

5.3 Equipment .................................................................................................................................................. 8

5.4 Weather Conditions .................................................................................................................................... 8

6. RESULTS ...................................................................................................................................................... 9

6.1 Environmental Noise Survey ....................................................................................................................... 9

6.2 Typical Background Noise Levels .............................................................................................................. 10

7. VIBRATION ................................................................................................................................................ 11

8. NOISE ASSESSMENT .................................................................................................................................. 12

8.1 Sources of noise ........................................................................................................................................ 12

8.2 Noise levels at facades .............................................................................................................................. 13

8.3 Outline Guidance for Building Envelope and Ventilation Strategy ............................................................ 13

9. OUTLINE DESIGN GUIDANCE – EXTERNAL PLANT ..................................................................................... 14

9.1 Overall combined noise limit .................................................................................................................... 14

9.2 Worst case scenario guidance noise limit for each unit ............................................................................ 15

10. SUMMARY AND CONCLUSIONS ................................................................................................................ 16

HYDROCK TECHNICAL REPORT | Rhondda Cynon Taf County Borough Council | Robertstown Development | ROB-HYD-XX-ZZ-RP-Y-0001 | 13 July 2018 iii

Tables

Table 1: BS 8233 Internal Noise Limits - Residential ................................................................................................ 5

Table 2: Survey Equipment ..................................................................................................................................... 8

Table 3: Weather Data ............................................................................................................................................. 8

Table 4: Summary Noise Levels – Position 1 .......................................................................................................... 10

Table 5: Typical Measured Background Noise Level LA90 ..................................................................................... 10

Table 6: Vibration Measurement Result ................................................................................................................ 11

Table 7: Vibration dose value ranges which might result in various probabilities of adverse comment within

residential buildings ............................................................................................................................................... 11

Table 8: Façade Noise Assessment ........................................................................................................................ 13

Table 9: Proposed combined 20 units noise limits ................................................................................................. 14

Table 10: Proposed guidance noise limits for each unit ........................................................................................ 15

Figures

Figure 1: Outline of the development site ............................................................................................................... 2

Figure 2: Measurement Positions ............................................................................................................................ 7

Figure 3: Environmental Noise Survey Measurement Graph - Position 1 ................................................................ 9

Figure 4: Proposed site option and distance to the main source of noise (the A4059) ......................................... 12

HYDROCK TECHNICAL REPORT | Rhondda Cynon Taf County Borough Council | Robertstown Development | ROB-HYD-XX-ZZ-RP-Y-0001 | 13 July 2018 1

Noise Planning Report

Robertstown Industrial Development

1. INTRODUCTION

Hydrock Consultants have been appointed by Rhondda Cynon Taf County Borough Council to provide acoustic

consultancy services in relation to the proposed Robertstown development.

Proposals have been made for the development of a light industrial park comprising of a number of modern

light industrial units (B1, B2 & B8) built to a BREEAM 'Very Good' Standard.

Planning legislation and guidance documents have been consulted in order to undertake a noise measurement

survey on the proposed development site.

Prevailing noise levels have been established for use in the design development and Planning Application

processes.

This report presents details of the noise assessment method, available to assess the acoustic impact of the

proposed development on the neighbouring area and any potential noise impact on the surroundings of the

proposed development itself.


2. DESCRIPTION - DEVELOPMENT SITE

Proposals have been made for the development of a light industrial park comprising of a number of modern

light industrial units.

The proposed development site is situated on a flat overgrown area of land bound by Wellington Street to the

north, a railway line and the A4059 to the south.

Following a site visit it was determined that the prevailing environmental noise levels in the area are dominated

by road traffic noise from the A4059. Based on the noise and vibration data it is assumed that the rail way line

was not in use during the noise survey.

The proposed development site is shown in Figure 1: Outline of the development site

Figure 1: Outline of the development site


3. PLANNING POLICY WALES

3.1 Edition 9 Chapter 13

"13.3 Reducing Noise and Light Pollution

13.13.1 Noise can affect people’s health and well-being and have a direct impact on wildlife and local amenity.

Noise levels provide an indicator of local environmental quality. The objective of a policy for noise is to minimise

emissions and reduce ambient noise levels to an acceptable standard. Noise Action Plans, drawn up by the Welsh

Ministers in relation to Wales under the Environmental Noise Directive, and the Wales Regulations, aim to

prevent and reduce environmental noise where necessary and preserve environmental noise quality where it is

good. They are a planning consideration in the use and development of land."

" 13.14 Development Plans and Noise and Lighting

13.14.1 Development plan policies should be designed to ensure, as far as is practicable, that noise-sensitive

developments, such as hospitals, schools and housing, that need to be located close to the existing

transportation infrastructure to facilitate access, are designed in such a way as to limit noise levels within and

around those developments. Such development should be located away from existing sources of significant noise

including air transport and some industrial activities or programmed development such as improved or new

roads. Policies should also be designed to ensure, as far as possible, that potentially noisy developments are

located in areas where noise will not be such an important consideration or where its impact can be minimised.

Local planning authorities should adopt policies to prevent potentially noisy developments in areas which have

remained relatively undisturbed by noise. Development plan policies should have regard to any relevant Noise

Action Plan, including the need to protect urban ‘quiet areas’ against an increase in noise."

"13.15 Development Management and Noise

13.15.1 Noise can be a material planning consideration, for example in proposals to use or develop land near an

existing source of noise or where a proposed new development is likely to generate noise. Local planning

authorities should make a careful assessment of likely noise levels and have regard to any relevant Noise Action

Plan before determining such planning applications and in some circumstances, it will be necessary for a

technical noise assessment to be provided by the developer

13.15.2 Special consideration is required where noise-generating development is likely to affect a protected

species, or is proposed in or near statutorily designated areas, including urban ‘quiet areas’ designated in Noise

Action Plans. The effect of noise on the enjoyment of other areas of landscape, wildlife and historic value should

also be taken into account."

3.2 Local policy

The Local Planning Authority applicable to the proposed development is Rhondda Cynon Taf County Borough

Council. The local Core Strategy document adopted in Arch 2011 covers noise and vibration as set out below.

Policy AW 10 - Environmental Protection and Public Health: Development proposals will not be permitted where

they would cause or result in a risk of unacceptable harm to health and / or local amenity because of:

2. Noise pollution;

9. Or any other identified risk to the environment, local amenity and public health or safety

unless it can be demonstrated that measures can be taken to overcome any significant adverse risk to public

health, the environment and / or impact upon local amenity.


5.63. Pollution may cause significant damage to human health, quality of life and residential amenity, as well as

impact upon both the natural and built environment. This policy will ensure that developments that would result

in unacceptably high levels of noise, light, water and / or air pollution are located away from residential areas

and other sensitive uses. The policy will also ensure that new development is not located in close proximity to

existing sources of pollution. Amenity is defined as the pleasant or satisfactory aspects of a location or features

which contribute to its overall character and the enjoyment of residents or visitors.


4. GUIDANCE DOCUMENTS

In order to establish satisfactory noise parameters for design purposes and assessment, other guidance sources

are necessary to be considered as there is nothing specific in the Planning Legislation.

4.1 British Standard 8233:2014

To address noise control in and around different types of buildings, appropriate guidance and criteria can be

taken from:

‘BS 8233:2014 Guidance on sound insulation and noise reduction for buildings (British Standards Institution)’

(BS 8233:2014).

The criteria are primarily intended to guide the design of new buildings and are flexible depending on the

situational circumstances.

Table 2 provides the BS 8233:2014 guidance criteria for indoor ambient noise levels in commercial properties

when they are unoccupied.

Note that in noise-making workshops, etc., the activity noise is dominant and so the internal ambient noise level is

not critical and BS8233 does not specified internal noise criteria for industrial premises.

It is therefore proposed to use the internal noise limits for offices for our purpose.

BS 8233 Internal Noise Limits - Office

Typical situation Design range LAeq,T

Restaurant 40-55

Open plan office 45-50

Night club, public house 40-45

Ballroom, Banqueting hall 35-40

Living room 35-40

Table 1: BS 8233 Internal Noise Limits - Offices

4.2 British Standard 4142:2014

Guidance on measurement of prevailing background noise and rating methods of external building services

noise can be taken from:

‘British Standard 4142:2014 Methods for rating and assessing industrial and commercial sound’

The methods described in BS4142:2014 provide an objective method for assessing the likelihood of disturbance

caused by industrial or commercial noise. It can be used to determine the following levels at external locations:

1. rating levels for sources of sound of an industrial and/or commercial nature; and

2. ambient, background and residual sound levels,

for the purposes of:

3. investigating complaints;

4. assessing sound from proposed, new, modified or additional source(s) of sound of an industrial

and/or commercial nature; and

5. assessing sound at proposed new dwellings or premises used for residential purposes.


Certain acoustic features can increase the perceived impact of a specific noise source. Where such features are

present at the assessment location, a character correction is added to the specific sound level to obtain the

rating level.

The significance of noise impact is initially estimated for the specific sound by subtracting the measured

background sound level from the rating level, and the following considered.

a. Typically, the greater this difference, the greater the magnitude of the impact.

b. A difference of around +10 dB or more is likely to be an indication of a significant adverse

impact, depending on the context.

c. A difference of around +5 dB is likely to be an indication of an adverse impact, depending on

the context.

d. The lower the rating level is relative to the measured background sound level, the less likely it is

that the specific sound source will have an adverse impact or a significant adverse impact.

Where the rating level does not exceed the background sound level, this is an indication of the

specific sound source having a low impact, depending on the context.

Where the initial estimate of the impact needs to be modified due to the context, all pertinent factors should be

taken into consideration.

4.3 Calculation of Road Traffic Noise

The ‘Department of Transport: Calculation of Road Traffic Noise: 1988 Section 43-44.’ shortened measurement

procedure has been used to calculate the predicted noise emissions of road traffic noise emanating from

surrounding roads.

The shortened measurement procedure outlined in section 43 provides the following guidance:

‘Measurements of L10 are made over any three consecutive hours between 10:00-17:00 hours. Using L10 (3-

hour) as the arithmetic mean of the three consecutive values of hourly L10, the current value of L10 (18-hour)

can be calculated from the relation:

𝐿10 (18 − ℎ𝑜𝑢𝑟) = 𝐿10 (3 − ℎ𝑜𝑢𝑟) − 1 𝑑𝐵(𝐴)

The Transport Research Laboratory (TRL) document ‘Converting the UK traffic noise index LA10 (18-Hour) to EU

noise indices for noise mapping’ PR/SE/451/02, outlines calculation methodology to calculate the Lday,

Levening, Lnight and Lden using the LA10 (18-Hour) noise index.

Calculation Method 3 for non-motorway traffic is shown below:

𝐿𝑑𝑎𝑦 = 0.95 𝑥 𝐿𝐴10 (18 − 𝐻𝑜𝑢𝑟) + 1.44 𝑑𝐵

𝐿𝑒𝑣𝑒𝑛𝑖𝑛𝑔 = 0.97 𝑥 𝐿𝐴10 (18 − 𝐻𝑜𝑢𝑟) − 2.87 𝑑𝐵

𝐿𝑛𝑖𝑔ℎ𝑡 = 0.90 𝑥 𝐿𝐴10 (18 − 𝐻𝑜𝑢𝑟) – 3.77 𝑑𝐵

𝐿𝑑𝑒𝑛 = 0.92 𝑥 𝐿𝐴10 (18 − 𝐻𝑜𝑢𝑟) + 4.20 𝑑𝐵


5. NOISE SURVEY

To enable an assessment of the baseline ambient noise levels in the area, environmental noise measurements

where undertaken on site between Thursday 3rd May 2018 and Tuesday 8th May 2018.

5.1 Methodology

The measurement locations were selected on the proposed development site in order to quantify the necessary

noise levels for the Planning Application stage.

Figure 2 shows the noise and vibration measurement positions.

Figure 2: Measurement Positions

5.2 Environmental Noise Monitoring

During the site visit an assessment of the noise climate of the proposed development location and its

surroundings was conducted.

The positions were selected in order to acquire prevailing background noise levels around the development

area in particular noise emissions emanating from the A4059 and the railway line.

Measurements were undertaken in accordance with the guidance outlined in the relevant British Standards,

BS 4142:2014 and BS 7445-1:2003.

The monitoring procedure followed the guidance outlined in BS7445:2003 Part 1, Section 5.2.3 and section

5.2.2. Measurements were undertaken within a ‘free field’ environment.

A wind shield was fitted to the monitoring equipment at all times.

The microphone was located at a height of approximately 1.5m above ground floor level.


5.3 Equipment

Details of the sound monitoring equipment used for the acquisition of the prevailing noise levels are provided in

Table 4.

Survey Equipment

Monitoring Location

Manufacturer Instrument Type Serial No. / Version Calibration Certificate Number

Position 1 Rion Sound Level Meter NL-52 01254312 No.C11030502

Position 1 Rion Pre-Amplifier NH-25 54394 No.C11030502

Position 1 Rion Microphone UC-59 08770 No.C11030502

Position 1 Rion Acoustic Calibrator NC-74 35157400 No.C02040201

Table 2: Survey Equipment

5.4 Weather Conditions

A record of the weather conditions as published by www.timeanddate.com was kept during the measurement

survey period from Thursday 3rd May and Tuesday 8th May 2018.

The outline details of which are presented in Table 3.

Weather Data

Period Mean Temperature

Degrees Celsius Events

Wind Speed m/s

Prominent Wind Direction

Thursday, 03 May 2018

14 Sunny .4.5 W

Friday, 04 May 2018

14 Mostly Sunny 2.2 SW

Saturday, 05 May 2018

19 Mostly Sunny 2.2 SE

Sunday, 06 May 2018

20 Mostly Sunny 2.2 S & N

Monday, 07 May 2018

20 Mostly Sunny 2.2 N & S

Tuesday, 08 May 2018

12 Mostly Sunny 5.8 W

Table 3: Weather Data

BS 4142:2014 provides the following guidance with regards to the acquisition of environmental noise

measurements and weather conditions:

‘An effective windshield should be used to minimize turbulence at the microphone.’

‘NOTE Windshields are generally effective up to wind speeds of 5 m/s’ and. ‘exercise caution when making

measurements in poor weather conditions such as wind speeds greater than 5 m/s.’

Average recorded wind speeds during the environmental noise measurement process marginally exceeded the

monitoring threshold level 5 m/s however, as shown in the results wind speeds did not have a detrimental

impact on measured noise levels.

Measurements are therefore considered to adhere to the guidance of the relevant British Standard and no

correction has been applied to prevailing noise levels.


6. RESULTS

6.1 Environmental Noise Survey

A single environmental noise surveys were undertaken at Position 1 on the proposed development site. A noise

level time history over the full measurement period of Positions 1 is presented in Figure 3, which demonstrates

the variability of noise on the proposed development site.

Calculations of the measured noise data were undertaken as per guidance outlined in Section 5.

The period of measurement was between Thursday 3rd May 2018 and Tuesday 8th May 2018.

Three main acoustic parameters were measured using a time interval of 5 minutes as described below.

• LAeq,T dB, defined as the ‘A’ weighted equivalent continuous sound pressure level. Over a defined

time period ‘T’, it is the sound pressure level equivalent to the acoustic energy of the fluctuating

sound signal. It is often referred to as the ‘ambient noise level’.

• LAmax,F,T dB, defined as the ‘A’ weighted maximum sound pressure level that occurred during the

time period ‘T’ acquired using a ‘fast’ time weighting (i.e. a sample every 125ms). It is commonly

used to describe the highest noise level that occurred during an event such as a vehicle pass-by.

• LA90,T dB, defined as the ‘A’ weighted sound pressure level exceeded for 90% of the measurement

period ‘T’. It is a statistical parameter and cannot be directly combined with other acoustic

parameters. It is generally used to describe the prevailing background noise level.

Figure 3 show graphical representations of the variations of the noise levels in time for positions 1 to as well as

a summary of day and night time ambient noise levels and typical background noise levels.

A noise level time history over the full measurement period of Positions 1 is presented in Figure 3, which

demonstrates the variability of noise on the proposed development site.

Figure 3: Environmental Noise Survey Measurement Graph - Position 1


A summary of the 16-hour daytime (0700hrs to 2300hrs) and 8-hour night time (2300hrs to 0700hrs) LAeq,T

and LA90 parameters for Position 1 are presented in Table 4.

Summary Noise Levels – Position 1

Period 03-May 04-May 05-May 06-May 07-May 08-May Overall

Daytime LAeq (16hour) dB

56.6 55.9 55.8 53.7 54.6 58.1 56.0

Night time LAeq (8hour) dB

54 53.9 51.8 51 51.2 52.5

Table 4: Summary Noise Levels – Position 1

6.2 Typical Background Noise Levels

A statistical approach has been adopted in line with the guidance of BS 4142:2014 in determining the typical

background noise levels.

The approach is to undertake a statistical analysis of the resulting daytime (0700-2300) and night time (2300-

0700) measurement periods in order to determine the representative and most commonly occurring values to

determine the typical background noise level.

The figures outlined in Table 5: Typical Measured Background Noise Level LA90 should be adopted for use in the

noise impact assessment.

Period 03-May 04-May 05-May 06-May 07-May 08-May Overall

Day time LA90 typical (16hour) dB

52 53.1 51.6 50 50.2 53.4 51

Night time LA90 Typical (16hour) dB

47 44.9 42.9 44 47.8 45

Table 5: Typical Measured Background Noise Level LA90


7. VIBRATION

A vibration measurement was undertaken at Position 2, the results are presented in Table 9.

Time X Y Z

03/05/2018 (16hr) 0.036 0.038 0.027

03/05/2018 (8hr) 0.031 0.022 0.022

04/05/2018 (16hr) 0.036 0.038 0.026

04/05/2018 (8hr) 0.031 0.022 0.023

05/05/2018 (16hr) 0.035 0.037 0.033

05/05/2018 (8hr) 0.031 0.023 0.023

06/05/2018 (16hr) 0.034 0.038 0.033

06/05/2018 (8hr) 0.031 0.024 0.023

07/05/2018 (16hr) 0.033 0.038 0.034

07/05/2018 (8hr) 0.030 0.033 0.022

Table 6: Vibration Measurement Result

The guidance “BS 6472 2008 - Guide to evaluation of human exposure to vibration in buildings Part 1” sets out

vibration dose value ranges to establish the probability of adverse comment by those who experience it. These

are presented in Table 10.

Place and Time Low Probability of Adverse Comment

Adverse Comment Possible Adverse Comment Probable

Residential Buildings 16 h Day

0.2 to 0.4 0.4 to 0.8 0.8 to 1.6

Residential Buildings 8 h night

0.1 to 0.2 0.2 to 0.4 0.4 to 0.8

Table 7: Vibration dose value ranges which might result in various probabilities of adverse comment within residential buildings

Note: For offices and workshops, multiplying factors of 2 and 4 respectively should be applied to the above

vibration dose value ranges for a 16-hour day.

Table 6 shows that the measured vibration levels are considerably lower than the vibration dose value ranges

which might result in various probabilities of adverse comment as shown in Table 7.

Based on the measured vibration levels, it can be assumed that no train used the rail way line during the time of

the survey.


8. NOISE ASSESSMENT

In order to protect the amenity of future tenants, it will be necessary to assess the noise intrusion due to all

external sources against the appropriate British Standards and relevant guidance.

Noise exposure criteria policy details are contained in the planning policy section of this report. The

requirements of BS 8233:2014 are detailed in the guidance documents section and provide appropriate

guidance on both internal and external noise levels.

8.1 Sources of noise

Based on the results of the noise and vibration survey it is seen that the rail way line was not used during the

time of the survey. Further to some investigations, it is seen that the rail way line use to carry coal from Tower

Colliery coal mine which was closed in 2008. Therefore, the main sources of noise are seen to be Wellington

Street and the A0459. However, the A4059 is seen to be relatively busier compare to Wellington Street and

hence being the dominant source of noise over the site. Figure 4 below shows the noise measurement location,

the proposed site layout option and the A4059.

Figure 4: Proposed site option and distance to the main source of noise (the A4059)


8.2 Noise levels at facades

As shown on Figure 4, the distance between the noise survey position 1 and the nearest proposed unit to the

A4059 are similar. Therefore, we can assume that the noise levels from the A4059 at the facades of the

different units will not exceed the noise levels recorded during the survey.

The units located further north to the site are closer to Wellington Street. However, road traffic noise from

Wellington Street was seen to be considerably lower than the A4059 and deemed to be negligible.

Based on the above statement and Table 4, it can be assumed that the noise levels at the façade of the

proposed light industrial units will reach 56dBA during day time.

8.3 Outline Guidance for Building Envelope and Ventilation Strategy

The sound insulation properties of the building envelope depend upon the external noise levels present at each

façade.

We would therefore advise that the development be designed to ensure internal noise levels in accordance with

the guidance of BS 8233:2014.

Table 8 assumes compliance with BS 8233:2014’s internal noise criterion and shows the level differences for

varying spaces within the proposed development.

The assessment has taken into account noise levels from the identified sources, i.e. the A4059.

Simple natural ventilation through the use of opening windows will provide a level difference (D) in the order of

10-15 dB.

Façade Room Use Predicted External (‘free-field’ corrected)

Proposed Internal (Maximum)

Minimum Level Difference (D)

Low Noise Exposure

Light industrial units

56 55 1

Table 8: Façade Noise Assessment

As shown in Table 8, the difference the external noise levels and required internal noise levels is 1dB. Hence no

particular façade design is required to mitigate external noise levels and natural ventilation can be achieve by

simple openings.


9. OUTLINE DESIGN GUIDANCE – EXTERNAL PLANT

The proposed light industrial units may incorporate building services plant which can potentially vent to external

locations or have externally located plant items. Additionally, the activities taking part within and outside the

units are capable of producing audible noise and may require noise control measures (and potentially vibration

control dependent on location).

The nearest noise sensitive properties have been identified as:

• Residential properties on Bridge Street

A statistical assessment of background noise levels has been undertaken in accordance with BS 4142:2014.

The typical background daytime and night-time noise levels at the long-term monitoring location are shown

below:

Typical background noise levels at Position 1:

• LA90 51 dB daytime (0700hrs to 2300hrs)

• LA90 45 dB night time (2300hrs to 0700hrs)

9.1 Overall combined noise limit

Typically, a proposed noise limit of prevailing background noise (as above) minus 5 dB(A) is advised for design

purposes in accordance with the procedures of BS 4142:2014. The proposed limits are shown below.

Proposed 20 units combined noise Limits

Parameter Period Noise Levels, dB

LAr,1hour Daytime (0700hrs to 2300hrs)

46

LAr,15mins Night Time (2300hrs to 0700hrs)

40

Table 9: Proposed combined 20 units noise limits

The noise limits above are ‘free-field’ levels at any height above ground and 1.0m from the nearest noise

sensitive property façade without any specific tone or character. If the plant noise will contain specific tones or

intermittent character, then a further 6 dB(A) penalty should be applied.

These noise limits apply to the overall combined operation of the proposed 20 units.


9.2 Worst case scenario guidance noise limit for each unit

As shown in Figure 4, twenty light industrial units are proposed to be built.

The contribution of each unit will depend on its noise levels and noise characteristic as well as the distance and

level of screening to the nearest residences.

Not knowing the noise levels of the future tenants of the proposed light industrial units it is difficult to give a

noise limit for each unit. However, as a worst case, assuming that each units will equally contribute to the

external background noise levels, each unit should not exceed the noise limits shown in Table 9 - 10log(20) to

take into consideration for the 20 proposed units.

Proposed guidance noise Limits for each unit (worst case scenario)

Parameter Period Noise Levels, dB

LAr,1hour Daytime (0700hrs to 2300hrs)

33

LAr,15mins Night Time (2300hrs to 0700hrs)

27

Table 10: Proposed guidance noise limits for each unit

Please note that this approach is based on the worst-case scenario that every unit equally contribute to the

overall background noise levels at the nearest residences and should therefore only be used as guidance

Furthermore, giving the same noise limit to all the units is deemed to be unfair for the units closest to the

nearest residences.

As good practice, we would advise to locate the noisiest tenants further away to the nearest sensitive

residences and to keep the closer units for quieter tenants.

Overall it will be the responsibility of each tenant to ensure that their activity noise levels in combination with

the other tenants meet the noise limits shown in Table 9.


10. SUMMARY AND CONCLUSIONS

Hydrock Consultants have been appointed by Rhondda Cynon Taf County Borough Council to provide acoustic

consultancy services for the proposed development of Robertstown.

Guidance standards have been referenced to establish satisfactory indoor noise levels, external noise levels and

methods for determining prevailing background noise levels using National and Local Planning Policy guidelines.

A noise survey of the site has been undertaken.

Noise risk assessments have been undertaken to inform the proposed master planning outcomes by

incorporating good acoustic design where possible.

Preliminary design advice relating to the sound insulation and ventilation design of the façades has been

provided based on measured noise levels. It is seen that no particular façade design is required to mitigate

external noise levels and that natural ventilation can be achieve by simple openings.

Maximum noise limits were given for the combined noise activities from the overall 20 proposed light industrial

units as well as guidance worst-case scenario individual noise levels for each unit. Note that it will be the

responsibility of each tenant to ensure that their activity noise levels in combination with the other tenants

meet the noise limits shown in Table 9.

In conclusion, assuming the measures outlined in this report are implemented, the development will meet the

requirements of the local authority and relevant guidance standards.

Documents

Robertstown Development