NOISE IMPACT ASSESSMENT KELLYSTOWN, DUBLN€¦ · NOISE IMPACT ASSESSMENT KELLYSTOWN, DUBLN Rp001N 2020001 (Kellystown, Dublin) 23 October 2020 Rp 001 2016055 (Dawson AD) 20 April

NOISE IMPACT ASSESSMENT

KELLYSTOWN, DUBLN

Rp001N 2020001 (Kellystown, Dublin)

23 October 2020

Rp 001 2016055 (Dawson AD)

20 April 2016

2 Rp001N 2020001 (Kellystown, Dublin)

PROJECT: NOISE IMPACT ASSESSMENT

PREPARED FOR: CASTLETHORN CONSTRUCTION UNLIMITED COMPANY AND

CASTLETHORN DEVELOPMENTS KELLYSTOWN UNLIMITED COMPANY

USHER HOUSE

MAIN STREET

DUNDRUM

DUBLIN 14

ATTENTION: BARRY KELLY

REPORT NO.: Rp 001N 2020001

Disclaimer

This report is provided for the stated purposes and for the sole use of the named Client. Irwin Carr Ltd

accepts responsibility to the Client alone that the report has been prepared with the skill, care and

diligence of a competent engineer, but accepts no responsibility whatsoever to any parties other than the

Client. Any such parties rely upon the report at their own risk.

Copyright

The concepts and information contained in this document are the property of Irwin Carr

Ltd. Use or copying of this document in whole or in part without the written permission of Irwin Carr Ltd

constitutes an infringement of copyright. Information shall not be assigned to a third party without prior

consent.

Document Control

Status: Rev: Comments Date: Author: Reviewer:

Final 1.0 23 October 2020 Liam McAleavey Shane Carr


TABLE OF CONTENTS

1.0 INTRODUCTION .............................................................................................................. 4

1.1 DEVELOPMENT DESCRIPTION ....................................................................................... 4

2.0 ASSESSMENT CRITERIA ................................................................................................ 5

2.1 Transport Noise Impacting Proposed Dwellings .................................................................. 5

2.2 BS8233:2014 Guidance on Sound Insulation and noise Reduction for Buildings ................ 7

2.3 World Health Organisation (WHO) .............................................................................................. 7

3.0 ENVIRONMENTAL NOISE SURVEY ................................................................................. 8

4.0 NOISE ASSESSMENT ................................................................................................... 10

4.1 Ambient Sound Levels ............................................................................................................. 10

5.0 PROPOSED RESIDENTIAL ASSESSMENT..................................................................... 11

6.0 NOISE PREDICTIONS ................................................................................................... 12

6.1 Source Noise Levels and Noise Model Inputs ........................................................................ 12

6.2 Receptors ................................................................................................................................. 13

6.3 Predicted Noise Levels ............................................................................................................ 14

6.3.1 Block 11………………………………………………………………………..……………………………..15

6.3.2 Block 13………………………………………………………………………..……………………………..15

6.3.3 Block 14………………………………………………………………………..……………………………..15

6.3.4 Block 16………………………………………………………………………..……………………………..16

6.3.5 Block 10………………………………………………………………………..……………………………..16

6.3.6 Block 18………………………………………………………………………..……………………………..16

6.3.7 Block 16A.…………………………………………………………………….……………………………..16

6.3.8 Block 23………………………………………………………………………..……………………………..16

6.3.9 Apartment Block A………………………………………………………………………..…….………..16

6.3.10 Apartment Block B………………………………………………………………………..……………...17

6.3.11 Apartment Block C………………………………………………………………………………………..17

6.3.12 Internal Noise Levels……………………………………………………..……………………………..17

6.3.13 External Amenity Areas…..……………………………………………..……………………………..18

6.4 BS8233 .................................................................................................................................... 18

6.5 WHO .......................................................................................................................................... 18

7.0 MITIGATION MEASURES ................................................................................................. 19

8.0 CONCLUSION ................................................................................................................. 19


1.0 INTRODUCTION

Irwin Carr Consulting has been commissioned by Castlehorn Construction Unlimited Company and

Castlethorn Developments Kellystown Unlimited Company, to undertake a noise impact

assessment in relation to a proposed residential development at land adjacent to the western and

southern boundaries of St. Mochta’s Football Club, Porterstown Road, Porterstown, Dublin 15.

The site lies directly adjacent to the south of the railway track, between Clonsilla and Coolmine

train stations. The east of the site is abutted by St Mochta’s Football Club and the south of the site

is abutted by Scoil Choilm Community National School.

A site location map is shown in Appendix A.

1.1 DEVELOPMENT DESCRIPT ION

The proposed development comprises 360no. dwellings, accommodated in 128no. houses and

3no. apartment buildings (232no. apartment units). Other development includes residential

internal amenity areas (c.380 sq m), 1no.childcare facility (c.278 sq m) and 1no. retail unit (c.98

sq m). Building height ranges from 1 to 8-storeys. Associated site development works include a

dedicated public park and amenity open space, new ‘Kellystown Link Road’ access road and

internal road, pedestrian and bicycle network, green route, pump station and other environmental

infrastructure and landscaping works.

The proposed development is situated 9.8km from Dublin City Centre. The site lies directly to the

south of the Dublin-Maynooth Railway Line.

The application area is dominated by railway and traffic noise from the surrounding transport

network.


2.0 ASSESSMENT CRITERIA

The proposed development is heavily dominated by traffic noise from the surrounding road

network. The impact of transportation noise on proposed residential developments are typically

assessed with reference to absolute noise levels.

ProPG: Planning & Noise – Professional Practice Guidance on Planning & Noise – New Residential

Development – May 2017 provides a methodology for assessing external noise impacts on

proposed residential development from transportation dominant noise environments.

Another method of assessment compares the predicted noise levels to absolute noise levels such

as the World Health Organisation Guidelines and BS8233:2014, which both outline absolute noise

levels.

For completeness, we have assessed the predicted noise levels from this site in line with both

criteria.

While these are British Standards, they are regularly used in the Republic of Ireland as a source of

guideline noise level.

2.1 Transpor t Noise Impact ing Proposed Dwel l ings

ProPG: Planning & Noise (ProPG) guidance was recently published in its final formal in May 2017

and supersedes the withdrawn Planning Policy Guidance Note 24 – Noise - PPG24. It provides

guidance for local authorities on the use of their planning powers to minimise the adverse impact

of noise.

In particular, it aims to:

• Advocate full consideration of the acoustic environment from the earliest possible stage of the development process;

• Encourage the process of good acoustic design in and around new residential development;

• Outline what should be taken into account in deciding planning applications for new noise-sensitive developments;

• Improve understanding of how to determine the extent of potential noise impact and effect; and

• Assist the delivery of sustainable development.

ProPG introduces an ‘Initial Site Noise Risk Assessment’ methodology which notes with higher

external noise levels the greater the risk of noise becoming a determining factor in the likelihood of

permission being granted.

ProPG also states,

“…in the special case where industrial or commercial noise is present in the site but is

‘not dominant’… its contribution may be included in the noise level used to establish the

degree of risk (and if included, this should be clearly stated).”


Figure 1: ProPG – Initial Site Noise Risk Assessment

ProPG advises that the noise risk assessment may be based on measurement or prediction (or a

combination) as appropriate and should aim to describe noise levels during a typical worst-case

24-hour day now or over the foreseeable future.

The assessment should include the combined free-field noise level from all sources of transport

noise that affect the site. In the case where industrial or commercial noise is present but not

“dominant” (i.e. where the effect would be likely to be rated as lower than adverse if a


BS4142:2014 assessment was to be carried out), its contribution may be included in the noise

level used to establish the degree of risk.

2.2 BS8233:2014 Guidance on Sound Insu la t ion and no ise Reduct ion for Bu i ld ings

Example absolute noise limits can be found in British Standard 8233:2014 – Guidance on sound

insulation and noise reduction for buildings. Table 8.7 of BS8233:2014 is replicated in Table 1

below:

Table 1: Indoor noise criteria

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

Resting Living Room 35 dB LAeq,16hour

Dining Dining room/area 40 dB LAeq,16hour

Sleeping Bedroom 35 dB LAeq,16hour 30 dB LAeq,8hour 45 dB LAmax

BS82331, in their consultation response as being an appropriate standard for this type of

assessment. Section 7.7.3.1 of this document states:

“For traditional external areas that are used for amenity space, such as gardens and patios, it is

desirable that the external noise level does not exceed 50 dB LAeq,T, with an upper guideline value

of 55 dB LAeq,T which would be acceptable in noisier environments. However, it is also recognized

that these guideline values are not achievable in all circumstances where development might be

desirable. In higher noise areas, such as city centres or urban areas adjoining the strategic

transport network, a compromise between elevated noise levels and other factors, such as the

convenience of living in these locations or making efficient use of land resources to ensure

development needs can be met, might be warranted. In such a situation, development should be

designed to achieve the lowest practicable levels in these external amenity spaces, but should not

be prohibited.”

This section clearly identifies the situation where people would want to live close to the transport

network, in this case the roads and railway around the site. BS8233:2014 relies upon the WHO

Guideline values in setting its criteria, but also identifies the need to balance the noise

environment with other planning considerations.

2.3 Wor ld Hea l th Organ isa t ion (WHO)

Example noise limits can be found in World Health Organisation (WHO) publication

Guidelines for Community Noise, 1999 states the following:

“For a good night’s sleep, the equivalent sound level should not exceed 30dB(A) for continuous

background noise, and individual noise events exceeding 45dB(A) should be avoided.”

And

“To prevent sleep disturbance with windows open, the LAeq sound level should not exceed 45dB

outside bedrooms at night-time.”

The WHO guidelines suggest that a slightly open bedroom window provided a sound reduction from

outside to inside of 15dB.

1 BS8233:2014 Guidance on Sound insulation and noise reduction for buildings


3.0 ENVIRONMENTAL NOISE SURVEY

Existing ambient noise levels were measured at the site from Friday 24 January 2020 to Friday 31

January 2020.

Measurements were carried out at two locations on the site using the following equipment:

• Larson Davos SoundExpert LxT Class 1 Sound Level Meter

• Larson Davis Class 1 (CAL200) Sound Calibrator

Instrumentation was check calibrated before and after the survey period.

The weather during the survey periods was dry and calm with wind speeds less than 0.5m/s.

The purpose of the survey was to assess existing “ambient” noise levels in the vicinity of the site.

Table 2 below describes the measurement locations for the background noise levels at the

proposed site, which are shown in Appendix A. The locations are deemed to be representative of

the noise levels on the site.

Table 2: Noise Survey Locations

Noise Monitoring Location (NML) OSI Grid Reference

1 306068, 237508

2 306132, 237709

Figures 2 and 3 show the measured noise levels at both locations along the site:

Figure 2: NML1


Figure 3: NML2


4.0 NOISE ASSESSMENT

4.1 Ambien t Sound Leve ls

For the purposes of the ProPG assessment the measured daytime and night-time ambient sound

levels are presented in Tables 3 and 4.

Table 3: Measured daytime and night-time ambient sound levels – NML1

Date Noise Level dB

LAeq,16hr Day LAeq,8hr Night

24 January 2020 *54.8 47.4

25 January 2020 54.6 47.4

26 January 2020 53.7 44.2

27 January 2020 55.4 43.8

28 January 2020 54.8 43.5

29 January 2020 55.2 44.3

30 January 2020 55.6 47.8

31 January 2020 *59.1 -

*Denotes less than full 16hr measurement period

Table 4: Measured daytime and night-time ambient sound levels – NML2

Date Noise Level dB

LAeq,16hr Day LAeq,8hr Night

24 January 2020 *54.9 45.9

25 January 2020 54.2 46.4

26 January 2020 53.5 47.6

27 January 2020 56.0 47.3

28 January 2020 56.3 46.4

29 January 2020 56.0 45.0

30 January 2020 57.4 49.4

31 January 2020 *57.4 -

*Denotes less than full 16hr measurement period


5.0 Proposed Resident ia l Assessment

At Noise Monitoring Location 1, the worst-case daytime was 59.1 dB LAeq,16hr and night-time was

47.8 dB LAeq,8hr. This diurnal pattern is typical of transportation noise, with greater daytime activity

than night-time.

For the purposes of the assessment, worst case daytime noise levels would equate to the lower

end of the ProPG category:

“at low noise levels, the site is likely to be acceptable from a noise perspective provided

that a good acoustic design process is followed and is demonstrated in an ADS which

confirms how the adverse impacts of noise will be mitigated and minimised in the

finished development.”

For the purposes of the assessment, worst case night-time noise levels would equate the lower






At Noise Monitoring Location 2, the worst-case daytime was 57.4 dB LAeq,16hr and night-time was

49.4 dB LAeq,8hr. This diurnal pattern is typical of transportation noise, with greater daytime activity

than night-time.

For the purposes of the assessment, worst case daytime noise levels would equate to the lower






For the purposes of the assessment, worst case night-time noise levels would equate the lower






ProPG states that through a full noise impact assessment and a robust Acoustic Design Statement

(Appendix D) identifying how noise at the development may be mitigated, it is considered likely that

the housing development would be acceptable.

Through the use of a SoundPlan noise model, the predicted noise impacts for the various facades

of each dwelling can be calculated.


6.0 Noise Predic t ions

For the purposes of the noise assessment, the noise emissions from the surround transport network at

the nearest noise sensitive receptors have been predicted using SoundPLAN acoustic modelling

software.

The model was implemented in SoundPLAN version 8.2, which is produced by Braunstein & Berndt

GmbH. The SoundPLAN implementation of ISO9613 has been tested in-house by SoundPLAN

developers to ensure calculated results are within 0.2dB of the standard.

The model is integrated, allowing noise from all sources, with prediction methodologies to be undertaken

simultaneously. The noise model takes into consideration the following parameters:

• Topographical effects

• Atmospheric absorption

• Ground absorption

• Screening effects

• Reflections

• Focusing effects

• Metrological conditions

The model predicts the propagation of noise for each octave-band and source-receiver pair and produces

a noise level contour map from which the noise levels at receiver locations can be determined.

6.1 Source Noise Leve ls and Noise Mod el Inputs

The SoundPlan noise model was calibrated to achieve 59.1 dB(A) and 47.8 dB(A) at noise monitoring

location 1 and 57.4 and 49.4 at noise monitoring location 2, representing the worst-case noise for

daytime and night-time respectively.


6.2 Receptors

33 receptor locations were identified representing each block of dwellings/apartments within the

proposed development. Each block is made up of a number of houses/apartments. A map of the

proposed development displaying each block and receptor location is provided in Appendix B. The

location of these receptors is presented in Table 5 below:

Table 5: Noise Sensitive Receptors

Location Co-ordinates

R1 – Block 11 306120 237692

R2 – Block 13 306077 237606

R3 – Block 14 East Dwellings 306007 237580

R4 – Block 14 West Dwellings 305980 237589





R9 – Block 18 North Dwellings 305896 237540


R11 – Block 18 South Dwellings 305880 237481


R13 – Block 16A North Dwellings 305958 237523

R14 – Block 16A East Dwellings 305951 237474

R15 Block 16A – West Dwellings 305918 237503

R16 – Block 16A South Dwellings 305920 237469


R18 – Block 23 North Dwellings 306027 237525

R19 – Block 23 South Dwellings 306007 237446


R21 – Block A West Dwellings West Facade 306082 237458

R22 – Block A West Dwellings East Facade 306099 237458

R23 – Block A East Dwellings North Facade 306143 237470

R24 – Block A East Dwellings West Facade 306129 237444


R25 – Block A East Dwellings East Facade 306146 237418

R26 – Block B East Facade 306067 237569

R27 – Block B North Façade 306061 237582

R28 – Block B West Façade 306028 237567

R29 – Block B South Façade 306034 237547

R30 – Block C East Façade 305827 237510

R31 – Block C South Façade 305816 237502

R32 – Block C West Façade 305795 237520

R33 – Block C North Facade 305822 237521

6.3 Pred ic ted Noise Leve ls

The predicted noise levels (LAeq to the nearest dB) at each receptor location are presented in Table

6. The worst-case floor for each house/apartment block has been included.

Table 6: Predicted Noise Levels

Location

Predicted Daytime noise

levels

LAeq,16hr

Predicted Night-time

noise levels

LAeq,8hr

R1 – Block 11 56.5 47.0

R2 – Block 13 56.6 46.7

R3 – Block 14 East Dwellings 49.4 39.8

R4 – Block 14 West Dwellings 45.6 36.7





R9 – Block 18 North Dwellings 47.8 38.5


R11 – Block 18 South Dwellings 49.7 39.7


R13 – Block 16A North Dwellings 48.7 39.3

R14 – Block 16A East Dwellings 53.0 43.1

R15 Block 16A – West Dwellings 48.1 38.5


R16 – Block 16A South Dwellings 52.8 42.8


R18 – Block 23 North Dwellings 52.4 42.6

R19 – Block 23 South Dwellings 54.5 44.5


R21 – Block A West Dwellings West Façade 50.8 41.0

R22 – Block A West Dwellings East Facade 59.8 49.8

R23 – Block A East Dwellings North Facade 61.2 51.3

R24 – Block A East Dwellings West Facade 56.4 46.7

R25 – Block A East Dwellings East Facade 68.4 58.4

R26 – Block B East Facade 56.4 46.5

R27 – Block B North Façade 53.0 43.3

R28 – Block B West Façade 42.1 33.9

R29 – Block B South Façade 50.9 41.0

R30 – Block C East Façade 50.4 40.9

R31 – Block C South Façade 48.0 38.8

R32 – Block C West Façade 37.1 30.9

R33 – Block C North Facade 48.3 39.1

6.3.1 Block 11

Block 11 of the proposed housing development will be exposed to daytime and night-time noise

levels in the mid-section of the ProPG category,





6.3.2 Block 13


levels in the mid-section of the ProPG category,





6.3.3 Block 14


levels in the lower end of the ProPG category,

“These noise levels indicate that the development site is likely to be acceptable from a

noise perspective, and the application need not normally be delayed on noise grounds.”


6.3.4 Block 16


levels in the lower end of the ProPG category,



6.3.5 Block 10


levels within the lower end of the ProPG category,



6.3.6 Block 18


levels within the lower end of the ProPG category,



6.3.7 Block 16A

The south and east dwellings of Block 16A of the proposed housing development will be exposed

to daytime and night-time noise levels in the lower end of the ProPG category,





The north and west dwellings of Block 16A of the proposed housing development will be exposed

to daytime and night-time noise levels in the lower end of the ProPG category,



6.3.8 Block 23

The north, south and east dwellings of Block 23 of the proposed housing development will be

exposed to daytime and night-time noise levels in the lower end of the ProPG category,





The west dwellings of Block 23 of the proposed housing development will be exposed to daytime

and night-time noise levels in the lower end of the ProPG category,



6.3.9 APARTMENT BLOCK A

All facades of Apartment Block A with the exception of East Dwellings East Façade (R25) of the

proposed housing development will be exposed to daytime and night-time noise levels in the ProPG

category,






East Dwellings East Façade (R25) of the proposed housing development will be exposed to

daytime and night-time noise levels in the mid-section of the ProPG category,

“As noise levels increase, the site is less likely to be suitable from a noise perspective and any

subsequent application may be refused unless a good acoustic design process is followed and

is demonstrated in an ADS which confirms how the adverse impacts of noise will be mitigated

and minimised, and which clearly demonstrate that a significant adverse noise impact will be

avoided in the finished development.”

6.3.10 APARTMENT BLOCK B

The north, south and east facades of Apartment Block B of the proposed housing development will

be exposed to daytime and night-time noise levels at the lower end of the ProPG category,





The west façade of Apartment Block B of the proposed housing development will be exposed to

daytime and night-time noise levels in the lower end of the ProPG category,



6.3.11 APARTMENT BLOCK C

The east facade of Apartment Block C of the proposed housing development will be exposed to

daytime and night-time noise levels at the lower end of the ProPG category,





The north, south and west façades of Apartment Block C of the proposed housing development will

be exposed to daytime and night-time noise levels in the lower end of the ProPG category,



6.3.12 Internal Noise Levels

Both ProPG and BS8233 Guidance on Sound Insulation and Noise Reduction for Buildings, 2014

recommend the following criteria inside dwellings:

Table 7: Indoor noise criteria

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

Resting Living room 35 dB LAeq,16hour —

Dining Dining room/area 40 dB LAeq,16hour —

Sleeping Bedroom 35 dB LAeq,16hour 30 dB LAeq,8hour

Based on a typical 15 dB reduction for an open window and the worst case external ambient

sound levels measured on site, internal sound pressure levels are expected to be in the region of

40.9 dB LAeq, 16hr during the day and 32.8 dB LAeq, 8hr at night, in excess with the internal noise

criteria as stated in Table 7.

For each dwelling/apartment block in the proposed development with the exception of the

Apartment Block A East Dwellings East Façade (R25), standard double glazing 4/12/4 is adequate

mitigation as it provides 31dB Rw (Engineering Noise Control – Bies and Hanson Acoustics in the

Built Environment), and will provide in excess of the required acoustic performance to meet the

BS8233 LAmax internal noise levels recommended criteria during the day and night.


For Apartment Block A East Dwellings East Façade (R25), upgraded acoustic laminate glazing

6/16/6.8mm provides 34dB RTra / 40dB Rw (Pilkington Option – Laminated Glass for noise

control), which provides in excess of the required acoustic performance to meet the BS8233

internal noise levels recommended criteria, day and night.

To ensure that windows do not have to be opened for prolonged periods, it is proposed to

incorporate an acoustic ventilation system (with an equivalent sound reduction index of 31/40 dB

Rw) into the proposed dwellings. The specification of the ventilation will comply with Technical

Booklet K1, which provides ventilation rates in Table 2.2, as replicated in Table 7 below.

An example of an effective acoustic ventilation system is Airvent SM Acoustic by Brookvent2 which

has a sound reduction index of up to 40dB. The product specifications are presented in Appendix

F.

Table 8: Whole dwelling ventilation rates

Number of bedrooms in dwelling

1 2 3 4 5

Whole dwelling

ventilation rate (l/s) 13 17 21 25 29

Notes:

In addition, the minimum ventilation rate should not be less than 0.3 l/s per m2 of internal floor area.

(This includes all floors, e.g. for a two-storey building add the ground and first floor areas).

This is based on two occupants in the main bedroom and a single occupant in all other bedrooms. This

should be used as the default value. If a greater level of occupancy is expected add 4 l/s per occupant

The information in relation to background ventilation rates provided does not address the rapid

ventilation provision, which will be addressed in the normal way with openable windows in all habitable

rooms. The effect will allow people to open windows as desired, but it will not be required to permit

background ventilation as this criterion will be addressed mechanically.

For each dwelling in the proposed development, standard cavity ‘two leaves of 102.5mm brickwork,

50mm cavity, rigid wall ties’ provides 54 dB Rw,, thus ensuring that internal noise levels as stipulated in

BS8233 are achieved, day and night.

The night-time LAmax for the measurement period exceeded for more than 15 times per night at

NML1 was 71.7 dB(A) and at NML2 was 69.8. The above mitigation measures will ensure that

internal noise levels should not exceed the 45 dB LAmax for the night-time period.

6.3.13 External Amenity Areas

The predicted levels for the outdoor amenity areas marginally exceed the World Health

Organisation guidelines of a maximum noise level of 55 dB LAeq at Block 11 and 13 only. To achieve

noise levels within the WHO guideline limit, it is proposed to install 2m high masonry walls,

enclosing the external amenity areas of these dwellings. These are shown in Appendix C.

6.4 BS8233

The daytime noise levels under BS8233 suggest an upper limit of 55dB LAeq for external noise

level in residential amenity areas, the maximum measured daytime levels are 59.1dB.

While this level should not be prohibitive for development in urban areas, the design should

consider the noise level on the site to mitigate noise in external areas.

6.5 WHO

The WHO criteria generally relate to the night-time sleep disturbance criteria. The 45dB level is not

exceeded at either of the monitoring locations, so the WHO noise level is complied with.


7.0 MITIGATION MEASURES

With the inclusion of a 2m high brick wall enclosing the external amenity areas of Block 11 and

Block 13 (as shown in Appendix C), noise levels will be reduced to a desired noise level below the

WHO upper limit of 55dB LAeq.

The communal private open spaces within the Apartment Blocks are acoustically protected by the

block itself, reducing noise levels to under the target noise level of 55 dB LAeq.

8.0 CONCLUSIONS

Irwin Carr Consulting has been commissioned by Castlehorn Construction Unlimited Company and

Castlethorn Developments Unlimited Company Kellystown to undertake a noise impact assessment in

relation to a proposed residential development at land adjacent to the western and southern

boundaries of St. Mochta’s Football Club, Porterstown Road, Porterstown, Dublin 15.

Extended measurements were carried out over the daytime and night-time periods at two specific

locations across the site. The measured noise levels were used to carry out a ProPG assessment

undertaken to determine the potential impact of the existing noise environment on the proposed

residences.

The impact of existing transportation noise sources on the proposed residential development has

been assessed. The ProPG Noise Risk Impact has been found to be low during the day and night,

indicating an Acoustic Design Statement is required. An Acoustic Design Statement is included

within Appendix C.

Further to ensuring each dwelling is installed with double glazing, the provision of acoustic ventilation

will ensure that internal noise levels should not exceed those as stipulated within BS8233.

The external amenity areas of Block 11 and 13 will be enclosed with 2m high masonry walls, ensuring

noise levels impacting these areas are within WHO guideline limits.

For the reasons outlined within this report, Irwin Carr Consulting is of the opinion that the noise burden

upon the proposed development would not be deemed excessive (further to mitigation measures as

outlined) and therefore noise should not be considered a negative determining factor when assessing

this application.


APPENDIX A SITE AND NOISE MONITORING LOCATIONS

**Note- The above diagram is not to scale and is for illustrative purposes only

NML2 Proposed Site

NML1


APPENDIX B SITE LAYOUT AND RECEPTOR LOCATIONS


R1

R2

R3

R4

R12

R9

R8

R7

R6

R5

R11

R10

R13

R14

R15 R16

R17

R18

R19

R20

Block C

Apartment Block B

Apartment Block A

11

13

18

10 16 14

16A 23


APARTMENT BLOCK A


R23

R21

R22 R24

R25


APARTMENT BLOCK B


R28

R29

R26

R27


APARTMENT BLOCK C


R30

R31

R32

R33


APPENDIX C EXTERNAL AMENITY AREA MITIGATION – BLOCK 11

2m high masonry walls


BLOCK 13

2m high masonry walls


APPENDIX D NOISE MODELLING

For the purposes of this assessment, computer modelling has been undertaken to accurately

predict noise emissions at the nearest residential properties due to the proposed development.

The model was implemented in SoundPLAN version 8.2, which is produced by Braunstein & Berndt

GmbH. The SoundPLAN implementation of ISO9613 has been tested in-house by SoundPLAN

developers to ensure calculated results are within 0.2dB of the standard.

The model is integrated, allowing noise from all sources, with prediction methodologies to be

undertaken simultaneously. The noise model takes into consideration the following parameters:

• Atmospheric absorption

• Ground absorption

• Screening effects

• Reflections

• Focussing effects

• Metrological conditions

The model predicts the propagation of noise for each octave band and source-receiver pair and

produces a noise level contour map. The noise level contours are colour coded for ease of

interpretation.

The ISO 9613-2: 1996 propagation model predicts sound pressure level at a field point using

equation [1]:

Lp = LWpoint + D – Adiv - Aatm - Aground - Ascreen - Amisc [1]

where:

• Lp is the sound pressure level at a field point

• Lwpoint is the sound power level of a point source

• D is the directivity index of the source in dB

• An are the attenuation allowances for geometrical divergence, atmospheric absorption, ground hardness, screening and miscellaneous effects.

Lwpoint – Point Source Sound Power Level

This data is expressed in terms of A-weighted decibels (dBA), for each integer multiple of the wind

speed range of interest in addition to linear 1/3 octave values from 50Hz to 10kHz or octave band

values from 63Hz to 8kHz.

D – Directivity Factor

The directivity factor (D) allows for an adjustment to be made to the radiated sound power level

where the source is understood to radiate higher levels of sound in the direction of interest.

Accordingly no directivity corrections have been used in our model.

Adiv – Unidirectional Spherical Divergence

For ISO 9613-2:1996 a turbine is considered to be a point source radiating sound energy in a free-

field. As such, sound energy propagating distance (r) will be attenuated according to the following

equation:

Adiv = 20log(r) + 11 dB [2]

Aatm – Atmospheric Absorption

Sound propagation through the atmosphere is considered to be a diabatic process in that as the

wave front propagates outwards from the source, energy is converted to heat. The attenuation

provided by this process is largely dependent on the relative humidity and temperature of the air

through which the sound propagates.


Aground – Ground Effect

The ISO9613-2:1996 standard describes three distinct ground surface types, namely hard, porous

and mixed ground and states the following:

• Hard ground includes paving, water, ice, concrete and all other ground surfaces having a low porosity.

• Porous ground includes ground covered by grass, trees and other vegetation, and all other ground surfaces suitable for growth of vegetables, such as farming land.

• Mixed ground consists of both hard and porous ground.

For the purposes of this assessment the ground factors were assumed to be 0.5

Ascreen – Acoustic Screening

. It should be noted that attenuation due to topographic screening is inherently calculated by

SoundPLAN from the digital terrain file.

Amisc – Miscellaneous Effects

No miscellaneous attenuation effects have been used within this model.


APPENDIX E ACOUSTIC DESIGN STATEMENT

An iterative approach has been taken to completing the noise impact assessment, commensurate with a Low to

Medium Risk Acoustic Design Statement. The purpose of Appendix C is to summarise the content of the noise

impact assessment to correlate with Figure 1 of the ProPG.

Level 1 Issues:

• Relevant noise sources identified – road and rail traffic dominant

• Assess extent of noise risk for unmitigated site (current and foreseeable future, 15 years ahead) –detailed in Table 3, current traffic levels are unlikely to change significantly in the foreseeable future,

highest value for week used to develop mitigation

• Opportunities to mitigate the noise source within the site – not applicable

• Maximise separation – not possible due to the limited area of the site

• Noise barriers – 2m high masonry walls enclosing external amenity areas of Block 11 and Block 13

• Site layout – protecting residential units - rear units protected by front units

• Site layout – protecting external amenity space – external amenity areas shielded by buildings

• Building layout to self-screen sensitive rooms – not relevant due to mitigation measures

• Building treatment to screen openings – not relevant due to mitigation measures

• Window location and size of affected facades - not relevant due to mitigation measures

• Façade insulation design –For each dwelling in the proposed development with the exception of the Apartment Block A, standard double glazing 4/12/4 is adequate mitigation.

• For Apartment Block A East Dwellings East Façade (R25), upgraded acoustic laminate glazing 6/16/6.8mm should be installed.

• Ventilation – natural from quiet façade - To ensure that windows do not have to be opened for prolonged periods, it is proposed to also incorporate a background acoustic ventilation system into the

proposed apartments.


APPENDIX F NOISE MAPS


APPENDIX G ACOUSTIC VENTILATION SYSTEM – AIRVENT SM ACOUSTIC

SM Acoustic Product Brochure, April 2018.

NOISE IMPACT ASSESSMENT KELLYSTOWN, DUBLN€¦ · NOISE IMPACT ASSESSMENT KELLYSTOWN, DUBLN Rp001N 2020001 (Kellystown, Dublin) 23 October 2020 Rp 001 2016055 (Dawson AD) 20 April

Documents