Sebastian Giglio Acoustic Consultant · 2016-03-14 · Sydney NSW 2000 By email:...

Sebastian Giglio

B Eng (Hons) Mech

Acoustic Consultant

Building Acoustics Mechanical Services Noise Environmental Noise

PO Box 8400

Mt Pritchard NSW 2170 Ph: (02) 8786 0912

Fx: (02) 8786 0913 Email: [email protected]

ABN 90 809 049 548

Ref: 204218C/D06 of 21

Building Acoustics: Sound Insulation, BCA Compliance, Offices, Studios, Auditoriums

Noise: Transportation(road, rail, aircraft) Mechanical Services Domestic Airconditioning

Environmental Occupational Industrial

Rail Noise Assessment – Proposed Residential

Development at Avon Road, Pymble

mailto:[email protected]

Ref: 204218C/D06 Avon Road, Pymble of 21

18 December 2015

Report prepared for:

Ausbao NSW Management Pty Ltd

C/-

Pricewaterhouse Coopers

Darling Park 201 Sussex Street

Sydney NSW 2000

By email: [email protected]

Report Name:

Rail Noise Assessment – Proposed Residential Development at Avon Road,

Pymble

Prepared by:

Sebastian Giglio

B Eng (Hons) Mech

Please note that this correspondence has only addressed the acoustical issues discussed. Other aspects of

building design, such as fire-rating, structural and waterproofing considerations must be referred to others.

Drawings shown are not for construction.

Table of Contents

1 Introduction ................................................................................................................. 3

2 Project/Site description ................................................................................................ 6

3 Noise Criteria .............................................................................................................. 7

4 Rail Noise Levels ........................................................................................................ 8

5 Recommended Noise Control Measures..................................................................... 12

5.1 Window Sound Rating and Thermal Rating ........................................................ 14

5.2 Sound-Rated Glazing .......................................................................................... 14

5.3 Recommended Window Sound Ratings .............................................................. 15

5.4 Heritage Building ............................................................................................... 15

6 Alternative Ventilation .............................................................................................. 17

7 Other Acoustic Items ................................................................................................. 20

7.1 Party Walls ......................................................................................................... 20

7.2 Garage Doors ..................................................................................................... 20

7.3 Mechanical Services Noise ................................................................................. 20

8 Conclusion ................................................................................................................ 21


1 INTRODUCTION

This Acoustic Report provides an assessment of rail noise impacts at the site of the proposed

multi-building residential development. This report has been prepared on behalf of Ausbao

Pty Ltd (The Applicant). The Report forms part of the Land and Environment Court of NSW

(L&E Court) Proceedings No.10834 of 2013. The proceedings relate to the refusal by the

Planning Assessment Commission (PAC), as delegate of the Minister for Planning

(Minister), of the Major Project Application (MP 10_0219) for a multi-unit residential

development at 1, 1A & 5 Avon Road and 4 & 8 Beechworth Road, Pymble (Site).

On 5 December 2014, the Land and Environment Court ordered that a Concept Plan approval

be issued in respect of the development of the Site, and the PAC issued the Concept Plan

Approval on 19 December 2014. The proceedings No.10834 of 2013 relating to the Major

Project Application were stood over following the Court's order regarding the Concept Plan

and the PAC's subsequent issue of the Concept Plan Approval. This report addresses the rail

noise impacts for the revisions to the Major Project Application as a consequence of the terms

of the Concept Plan Approval.

The following documents have been used in the preparation of the Report:

NSW Infrastructure SEPP (State Environmental Planning Policy) 2007

NSW Department of Planning Development Near Rail Corridors and Busy Roads –

Interim Guideline (2008)

DA Architectural Drawings, Issue U, prepared by Marchese Partners

Figure 1-1 shows an aerial photograph of the site and surrounds. Figure 1-2 shows the site

plan.

Potential acoustic issues that are covered in this report include:

Indoor noise intrusion from rail passbys.

The proposed development involves construction of four new houses on the site, retention of

a heritage listed residence and construction of three multi-residential apartment buildings

(Building 1, Building 3 and Building 4).


Figure 1-1 Site Aerial Photo

Measurement Locations

1 2


Figure 1-2 Site Plan

Building 4

Building 3

Building 1

Heritage House

House 1

House 2

House 3

House 4


2 PROJECT/SITE DESCRIPTION

The proposed development involves construction of four new houses on the site, retention of

a heritage listed residence and construction of three multi-residential apartment buildings

(Building 1, Building 3 and Building 4). Total site area is 24,610m2.

As can be seen in Figure 1-2, the site is bounded by other residential lots except on the north-

eastern boundary where it is bounded by the rail corridor for the T1 North Shore & Northern

Line. This line is not used by freight rail traffic but only electric passenger trains.


3 NOISE CRITERIA

The NSW Department of Planning has produced a document titled Development Near Rail

Corridors And Busy Roads – Interim Guideline. This document addresses and expands upon

the indoor noise goals in the NSW Infrastructure SEPP and provides a central document for

assessment of rail noise affecting residential land developments in NSW. In the past, a

number of documents existed (and still exist) for this purpose: including Development

Control Plans issued by Hornsby Council, North Sydney Council, various other Councils and

Council bodies such as the Southern Sydney Regional Organisation of Council’s (SSROC),

as well as State Rail’s publication Interim Guidelines for Applicants – Consideration of Rail

Noise and Vibration in the Planning Process.

The noise criteria of all these separate documents is reasonably similar (as one would expect)

with subtle differences. In general, the principle goal is based upon consideration of the total

acoustic energy experienced by residential occupants indoors within habitable rooms of

apartments and houses. Acoustic energy is additive logarithmically and appears to provide

good correlation with subjective experience.

The Department of Planning goals for noise within residences are as follows:

35dBA LAeq(9-hours) for bedrooms, during the period 10pm-7am;

40dBA LAeq(15-hours) for other habitable rooms, during the period 7am-10pm;

If internal noise levels with windows or doors open exceed the criteria by more than

10dBA, the design of the ventilation for these rooms should be such that occupants can

leave windows closed, if they so desire, and also to meet the ventilation requirements of

the Building Code of Australia.

The 10dBA allowance with doors/windows open is based on the widely accepted premise

that a noise reduction of 10dBA can be achieved through an open window (based on the

façade-reflected sound level).

As a general guide, habitable rooms of a dwelling will require acoustic attenuation of the

façade, other than conventional glazing, when the following façade-reflected noise levels are

exceeded:

55dBA LAeq(9-hours) for bedrooms (52.5dBA free-field),

60dBA LAeq(15-hours) for other habitable rooms (57.5dBA free-field).

Note that the corresponding free-field sound levels are 2.5dBA lower (the magnitude of

façade-reflectrion effects on measured sound levels).


4 RAIL NOISE LEVELS

NSW Transport (Railcorp) has previously accepted the noise measurements carried out at the

site by this office in 2012. The same rolling stock predominates and so these noise levels

have been used for this assessment. For much of the site, the railway line is in cutting.

Therefore, the lowest levels of each building will be shielded from rail noise. However, the

upper levels will have an “acoustic” direct line-of-sight of the railway line (the actual view

may be obscured by trees and foliage, but in general, vegetation provides minimal or no

acoustic shielding).

Noise levels have been measured at two locations on the site, shown in Figure 1-1. The first

location is at the nearest corner of Building 4 to the railway line. Measurements were carried

out at 1.5m above the ground and this location was shielded from the rail tracks, although the

tops of the trains were visible. (It is noted that for electric passenger trains, most of the noise

is generated at the wheel-track interface. Since the rail tracks are in cutting there would have

been some reflected noise also included in the measurement from the other side of the

cutting).

The second measurement location was just outside the site boundary, overlooking the tracks,

with direct line-of-sight, approximately 13m from the nearest track. This was done in order

to obtain a measurement that could be extrapolated to upper levels of the apartment buildings,

where there is little or no acoustic shielding of the tracks from the apartments. It is noted

that this measurement location, Measurement Location 2, is much closer to the tracks than

the residential apartments.

The noise measurements are summarised in Table 4-1 below.

Table 4-1 Summary of Noise Measurements at the Site, Carried Out on 21

November 2012

Time Location SEL Sound

Level, dBA

LAmax Sound

Level, dBA

Log Average

SEL

11:19am 1 (shielded) 69.6 61.1

11:31am 73.7 64.9

11:34am 73.3 65.7

11:50am 68.0 60.7

12:03pm 68.0 61.7

12:07pm 72.4 63.9

12:10pm 72.1 64.1

12:34pm 2 (not shielded) 86.7 79.1

12:34pm 91.6 72.8

12:47pm 88.5 81.4


Time Location SEL Sound

Level, dBA

LAmax Sound

Level, dBA

Log Average

SEL

12:49pm 83.2 76.1

1:03pm 81.4 74.5

1:05pm 84.2 76.2

1:17pm 85.0 77.8

1:19pm 84.4 76.2

1:33pm 90.4 84.1

86.0 dBA

The SEL sound level (Single Event Level) is a shorthand descriptor of the total energy of a

noise event – in this case a train passby. It is the sound level that for a 1 second duration has

the same total energy as the event being measured. (For example, if a noise event that is

being measured has a sound level of 70 decibels (dBA) and lasts for 10 seconds, then the

SEL would be 80dBA. 70dBA over 10 seconds has the same total energy as 80dBA for 1

second).

In order to determine LAeq from SEL, the total energy of all train passbys is summed and

logarithmically divided by the time taken (in this case, 9 hours or 15 hours); see the relation

below. The result of these calculations are shown in Table 4-3 below. Note that the numbers

of trains has been determined from Sydney Trains timetables – see Table 4-2.

LAeq,15-hours = SEL (train passby) + 10*Log10(N) – 10*Log10(T)

N = number of trains in 15 hours (or 9 hours),

T = number of seconds in 15 hours (or 9 hours)

Table 4-2 Summary of Typical Weekday Rail Movements Passing the Site (both

directions)

Time Period Northbound Southbound Total

Midnight-1am 5 0 5

1-2am 1 0 1

2-3am 0 0 0

3-4am 0 0 0

4-5am 1 2 3

5-6am 1 5 6

6-7am 4 7 11

7-8am 6 9 15

8-9am 9 7 16


Time Period Northbound Southbound Total

9-10am 8 5 13

10-11am 5 4 9

11am-midday 4 4 8

Midday-1pm 5 4 9

1-2pm 4 4 8

2-3pm 4 5 9

3-4pm 8 8 16

4-5pm 7 11 18

5-6pm 8 8 16

6-7pm 6 6 12

7-8pm 6 4 10

8-9pm 4 4 8

9-10pm 4 4 8

10-11pm 4 4 8

11pm-Midnight 4 3 7

The number of trains in each assessment period is:

Night-time (7am-10pm): 41

Daytime (7am-10pm): 175

Table 4-3 Summary of calculated rail noise exposure (free-filed noise level at the

most exposed façade of the building), dBA

Location

Distance from

Centreline between

Both Tracks

Acoustic

Shielding

Night-time

(Bedrooms) Rail

Noise LAeq,9hrs

Daytime (Other

Habitable Rooms)

Rail Noise LAeq,15hrs

Microphone at

Boundary 15m NA 58 61

Building 1 40m Partial shielding 46 49

Building 3 70m Well shielded ≤42 ≤45

Building 4 23m None 56 59

House 1 38m Minor shielding 54 57

House 2 40m Partial shielding 51 54

House 3 60m Well shielded 42 45

House 4 76m Well shielded ≤40 ≤44

Heritage House 27m Partial shielding 50 53


The calculated rail noise exposure in Table 4-3 above takes into account shielding by the

embankment as a result of the trains being in cutting past the site. Building 4, House 1 and

House 2 have rail noise exposure higher than the Infrastructure SEPP indoor acoustic amenity

goals. The other buildings comply. However, given the intended quality of the development,

it is recommended that House 3 and Building 1 are also treated to meet a lower noise goal.

Note that the Heritage House will not be used as a residence under the current development

proposal. However, for the purposes of this assessment, it will be considered as such.


5 RECOMMENDED NOISE CONTROL MEASURES

In order to control indoor noise levels from trains and provide acoustic amenity that meets

the published noise guidelines, it is necessary to provide the following for noise-affected

apartments:

Sound-rated windows;

Alternative ventilation.

Alternative ventilation is discussed in the next Section of the Report. The extent of sound-

rated windows and alternative ventilation is outlined in this Section of the Report.

Figure 5-1 Acoustic Zone Plan of Beechworth Road Houses

ZONE A ZONE B


Figure 5-2 Acoustic Zone Plan of Avon Road Apartment Buildings and Heritage

House

ZONE A


5.1 Window Sound Rating and Thermal Rating

The sound-rated windows for this project will be specified in terms of the sound rating of the

window rather than a thickness of glass requirement. This does not replace any required

BASIX or the like thermal rating but is an adjunct to it. Monolithic sound-rated glass can be

E-coated or the like without affecting the sound rating. Tinted or thermal glass interlayers

have the same acoustic effectiveness as standard PVB laminated glass interlayers. Where

windows are required to be double-glazed (Insulated Glazing Units) then the required

window performance becomes a minimum, both in terms of thermal performance

requirements (refer to others) and acoustic performance requirements (outlined in this

Report). In this Section of the Report, suggested minimum glass thicknesses are nominated

that may achieve the recommended required sound rating; these apply to single glazed

windows only and where sound-rated windows are required, the manufacturer should always

furnish an Acoustic Test Certificate or documentation verifying the sound rating of the

window system to be installed.

Any window schedule prepared for the project should include both thermal and sound ratings

for each window.

5.2 Sound-Rated Glazing

This Section of the Report summarises the required glazing acoustic ratings. For reference

purposes, the following glass thicknesses would be expected to achieve the nominated

ratings:

Table 5-1 Summary of Minimum Expected Glass Thickness To Achieve Sound

Insulation

Nominated Sound Rating Indicative Minimum Glass Thickness

“Conventional” or “No Rating”

This refers to weight-for-size glass that conforms to the Australian

Standard and is only required to provide modest levels of sound

insulation against external noise. Typically, these windows provide

sound insulation around Rw+Ctr 20 when fitted with 3mm glass and

good quality weather/acoustic seals.

Rw+Ctr 22 4mm glass

Rw+Ctr 24-26 5mm glass

Rw+Ctr 27 6mm glass

Rw+Ctr 28-30 6.38mm laminated glass

Rw+Ctr 31-32 10.38mm laminated glass

In general, sound-rated windows must be provided in substantial frames and be fitted with

suitable acoustic seals such as Schlegel or equivalent.


The windows provided for this project should have valid test certificates from a recognised

acoustic laboratory or otherwise be accompanied by evidence that the windows and window

frames can provide the required sound insulation rating.

The above “indicative minimum glass thickness” applies to single-glazed windows only.

Double glazed (Insulated Glazing Units) windows will have different sound ratings and the

sound rating must be used rather than the glass thickness for specifying the window.

5.3 Recommended Window Sound Ratings

Figure 5-1 and Figure 5-2 show the extent of façade acoustic treatment. The required sound

rating applies to all external windows and doors.

Zone A requires Rw+Ctr 28 windows and external doors;

Zone B requires Rw+Ctr 24 windows and external doors.

Habitable rooms in both Zone A and Zone B will also require Alternative Ventilation as

discussed in the next Section of the Report. Apartments outside of these zones do not require

any specific acoustic treatment.

Thermal Double Glazing

Possible double glazed configurations that meet or exceed the above sound ratings are

suggested below. The glazing supplier must in all cases provide documentary evidence that

the sound rating of the windows to be installed meet or exceed the nominated ratings.

Rw+Ctr 28.

6mm glass – 12mm gap – 6mm glass

Rw+Ctr 24.

3mm glass – 12mm gap – 4mm glass

5.4 Heritage Building

The Heritage Building is currently not proposed to be used for residential purposes. It will

have future uses as a sales office for the residential apartments, as a home-office, as common-

use facility for the occupants of the residential apartment buildings. For the purposes of this

assessment, however, it has been treated as residential. Therefore, it has the same glazing

requirements as outlined above (Zone A Acoustic Treatment). In addition, the lightweight-

framed nature of parts of the building façade also has the following sound insulation

requirements:

Roof insulation minimum R2.5 insulation batts;


Skylights to be treated equally to other glazing;

External non-masonry walls, to be externally lined with fibre cement and cement render.

Internal lining to consist of two layers of 13mm plasterboard. Wall cavity insulation to

be R2.5 wall batts.

Brick vents in external masonry walls should be blanked off on the internal wall leaf via

cement render or plastering at least 15mm thick or 9mm CFC (Compressed Fibre

Cement) sheet.


6 ALTERNATIVE VENTILATION

When windows are required to be kept closed in order to meet the indoor noise goals in

habitable rooms, then alternative ventilation must be provided to those rooms.

The provision of alternative ventilation can be achieved in a number of ways. Some of these

options are described in principle below. This presentation is suitable for the Development

Application stage of a project. As the design evolves, a mechanical engineer should confirm

that the final design complies with the requirements of the relevant ventilation Standard.

Option 1

Fully ducted air-conditioning with the provision of Outside Air included. In general,

domestic air-conditioning systems provide recirculated air only and do not include the

provision of outside air by default – it must be specified at the time of tendering/ordering.

Commercial ducted air-conditioning systems usually do have provision for outside air as a

standard feature.

Option 2

A proprietary wall-mounted acoustic ventilation system, such as Aeropac. Aeropac units are

approximately $650 each (per habitable room). These are available from Acoustica,

www.acoustica.com.au , ph: 1300 722 825.

Figure 6-1 Example of proprietary wall-mounted ventilation unit that provides air

filtering as well as noise control

In all cases a Mechanical Engineer should certify that the ventilation requirements have been

met.


Option 3

Provision of an attenuated air inlet in an external facade and cross-flow induced airflow via

operation of the apartment exhaust fans (i.e. toilet exhaust fan, bathroom exhaust fan, laundry

exhaust fan, kitchen exhaust fan). An attenuated air inlet could be a proprietary unit such as

“Silenceair”. Silenceair is particularly suited to brick veneer construction.

Figure 6-2 SilenceAir external ventilation bricks

Silenceair® units are approximately $180 each and are installed at the time that the external

wall is being constructed. It is usual to provide a note on the windows to apartments to switch

on the exhaust fans; alternatively, the exhaust fans can be interlocked electronically to turn

on by default when all the windows are closed. Occupants can override this setting, for

example during cold weather. These devices are available from www.silenceair.com

Note that it would be necessary to provide transfer ducts or undercut doors (15-20mm) in

habitable rooms to ensure that cross-flow induced ventilation takes place.

http://www.silenceair.com/


Option 4

Similar to Option 3 but with an alternative attenuated air inlet provided by the Builder. This

could consist of a simple external air grille in the brick wall, connected to a 1.2m long

internally insulated plasterboard bulkhead; for example, with acoustic flexible duct.

In all cases, a mechanical engineering consultant should certify that the ventilation

requirements have been met.


7 OTHER ACOUSTIC ITEMS

7.1 Party Walls

In general, the Party Walls between apartments will comply with the requirements of Part F5

of the Building Code of Australia, that is, Rw+Ctr 50 and discontinuous construction in cases

where there is a wet-area or kitchen on one side of the wall and a other habitable room on the

other side. Corridor walls will be Rw 50. Services will be insulated with Rw+Ctr 40

construction for habitable rooms and Rw+Ctr 25 for non-habitable rooms.

7.2 Garage Doors

Garage doors of multi-residential developments can sometimes create a noise issue for

neighbouring residential dwellings as well as for apartments in the same development. In

order to minimise this, the following should be implemented:

Garage door guides and motors should be installed with vibration-isolated support

brackets;

Motors should be soft-start and soft-close;

The edges of doors should incorporate nylon or similar wheels fitted within the guides,

fitted with ball bearings;

Hinges for sectional panel-lift doors should be low-friction type such as a hard-wearing

polymer (plastic) or other low-noise hinge.

7.3 Mechanical Services Noise

Noise emission from the site will need to be determined once the project is further advanced,

prior to design of mechanical services to enable allowable noise emission goals to be set with

respect to Council, EPA and NSW legislation guidelines.


8 CONCLUSION

This Acoustic Report has investigated the implications for rail noise for the new residential

buildings proposed for the development at Avon Road and Beechworth Road, Pymble. It has

been found that Building 4, House 1 and House 2 require acoustic treatment to meet the

Infrastructure SEPP requirements for indoor rail noise. Acoustic treatment has also been

suggested for some of the other buildings for reasons of enhanced acoustic amenity (although

this is not strictly necessary for compliance of these additional buildings with the

Infrastructure SEPP acoustic amenity goals). The actual glazing requirements are relatively

modest. A number of possible systems for alternative ventilation were presented in the

Report.

In conclusion it has been found that rail noise levels are not particularly high at the site and

that the NSW Department of Planning guidelines can be met in a relatively straightforward

manner.

Sebastian Giglio Acoustic Consultant · 2016-03-14 · Sydney NSW 2000 By email:...

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