Rochdale Holdings Pty Ltd A.B.N. 85 009 049 067 trading as: HERRING STORER ACOUSTICS Suite 34, 11 Preston Street, Como, W.A. 6152 P.O. Box 219, Como, W.A. 6952 Telephone: (08) 9367 6200 Facsimile: (08) 9474 2579 Email: [email protected]AMBIENT NOISE LEVEL ASSESSMENT 440 WILLIAM STREET, EAST PERTH BY HERRING STORER ACOUSTICS FOR DOMINATION HOMES NOVEMBER 2012 OUR REF: 15509-1-12201 ITEM 9.1.4
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AMBIENT NOISE LEVEL ASSESSMENT - City of Vincent · 2019-10-23 · Nick Della Gatta Structural Mechanical Electrical Hydraulic Acoustic Fire & B.C.A. Structerre Consulting Engineers
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DOCUMENT INFORMATION Author: George Watts Checked By: Tim Reynolds Date of Issue : 29 November 2012
REVISION HISTORY Revision Description Date Author Checked
DOCUMENT DISTRIBUTION
Copy No. Version No. Destination Hard Copy Electronic Copy
1 1 Domination Homes
This report has been prepared in accordance with the scope of services and on the basis of information and documents provided to Herring Storer Acoustics by the client. To the extent that this report relies on data and measurements taken at or under the times and conditions specified within the report and any findings, conclusions or recommendations only apply to those circumstances and no greater reliance should be assumed. The client acknowledges and agrees that the reports or presentations are provided by Herring Storer Acoustics to assist the client to conduct its own independent assessment.
4.0 MEASUREMENTS 3 5.0 CALCULATIONS 5 6.0 REQUIRED CONSTRUCTION 5
6.1 Walls 5 6.2 Glazing 5 6.3 Roof/Ceiling 6
7.0 CHARACTER OF INTRUSIVE NOISE DISCUSSION 6
APPENDICES
A Development Plans B Location Plan C Monitoring Results D One-Third Octave Band Data
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1.0 INTRODUCTION
An assessment has been undertaken of the ambient noise levels for the residential section of the proposed development at 440 William Street, Perth, to determine construction requirements to meet acceptable internal noise levels as required by the Town Of Vincent Sound Attenuation Policy. The critical noise source contributing to the ambient levels at the residential section of the development is the neighbouring nightclub. The assessment consisted of:
1. Site inspection and measurements of the ambient noise levels. 2. Determine the minimum construction requirements to achieve acceptable internal
noise levels. The details and results of the above are provided within this report.
2.0 CONCLUSION
To meet the requirements of the of Town of Vincent Sound Attenuation Policy the internal allowable LAeq noise levels for bedrooms and living areas have been set at 35 and 40 dB(A) respectively. Noise levels associated with the neighbouring nightclub are such that upgraded construction measures are required for the residential section of the development – particularly glazing treatments. With the proposed upgraded constructions, the internal sound levels set by the Town of Vincent Sound Attenuation Policy can be complied with, however the low frequency content of the noise emissions are such that they are likely to remain both audible and annoying within the proposed apartments.
3.0 CRITERIA
The Town of Vincent Sound Attenuation Policy recommends the following noise levels within Residential Buildings:
Residential buildings are to be deigned to achieve the following sounds levels :
• Leq 35 dB(A) in sleeping areas (bedrooms); and • Leq 40 dB(A) in living/work areas and other habitable rooms.
4.0 MEASUREMENTS
Due to the location of the proposed residential section of the development, on the fourth floor, the noise source of primary consideration was the adjacent nightclub. See Appendix A and B for development plans and location plans respectively. Noise emissions associated with the nightclub were recorded between 22nd and 26th November 2012, which encompasses a weekend. The noise emissions were recorded at approximately the height and location of the proposed apartment façade adjacent to the nightclub, as shown in Figures 1 and 2 below.
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FIGURE 1 – LOGGER LOCATION
FIGURE 2 – LOGGER LOCATION RELATIVE TO NEIGHBOURING NIGHTCLUB
The results of the monitoring are shown in Appendix C, with the one-third octave band analysis, for a typical time during which the nightclub noise emissions was prominent in Appendix D. Noise levels for the 15 minutes period where nightclub noise was prominent (midnight 24/11/2012) were measured at 59 dB LA10. The LA10 parameter has been used for the assessment, as this is the parameter prescribed by the Environmental Protection (Noise)
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Regulations 1997 – which governs noise emissions within Western Australia – and ensures a conservative assessment of the impact on the proposed residential apartment. Noise emissions associated with other sources in the area are considered to be limited to traffic noise. Due to construction noise dominating typical peak traffic periods, the monitoring on the 25th November 2012 (Sunday) is the only period representative of “typical” traffic conditions – albeit during periods of lesser flow than a typical weekday. Based on other developments in the area, a traffic noise level of 55 dB(A) has been conservatively assumed for the facades of the proposed apartments, based on the setback of the apartments from the road. It is noted that at the measured noise levels associated with the neighbouring nightclub, the nightclub is conservatively estimated to exceed the requirements of the Environmental Protection (Noise) Regulations 1997 by in the order of 25 dB, after 10pm.
5.0 CALCULATIONS
Calculations were carried out to determine the noise that would be received within the proposed apartments due to passing vehicles. Guidance on the calculations was taken from AS 3671-1989 “Acoustics – Road traffic noise intrusion-Building siting and construction”. The results of the calculations indicate the following minimum Rw ratings are required for the façade of the apartment nearest to the adjacent nightclub. Rw Rating Unit 4 – Bed 2 36 Unit 4 – Bed 1 36 Unit 4 – Living (sliding door) 28 Unit 2 – Bed 1 34 Unit 2 – Living 27 Unit 2 – Living (sliding door) 28 Ceilings- Living 33 Ceiling – Bedrooms 38
6.0 REQUIRED CONSTRUCTION
6.1 Walls
Standard wall constructions will satisfy the Rw ratings, and therefore no additional noise amelioration is required for the wall.
6.2 Glazing
Where the required Rw rating is less than 20, there are no specific constructions required and standard constructions will provide adequate noise reductions. Where the required Rw ratings are higher, the following tabulation indicates the types of construction that would be appropriate. It is noted that these are given as examples only, with confirmation of the performance recommended to be attained from the glazier prior to installation.
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Table 1 – Construction Requirements and Corresponding RW Values
25 to 27 Openable – 6mm glass in awning type windows with mechanical winders closing on compressible seals. Fixed – 6mm glass
28 to 30
Openable – 6.38mm laminated glass in awning type windows with mechanical winders closing on compressible seals. Fixed – 6.38mm laminated glass Fixed – 10mm glass
31 to 34 Openable – 10.38mm laminated glass in awning type windows with mechanical winders closing on compressible seals. Fixed – 10.38mm laminated glass
34 to 37 Openable – 12mm laminated glass in awning type windows with mechanical winders closing on compressible seals. Fixed – 12mm laminated glass
6.3 Roof/Ceiling
The ceiling construction should be confirmed prior to construction, however generally typical ceiling constructions would be sufficient for the calculated Rw ratings within living areas. Assuming a metal deck roof, it is recommended that a second layer of plasterboard be installed within the bedrooms. The attenuation path of the sky lights shown on the provided drawings would need to be confirmed to match the required ceiling/roof sound attenuation requirements.
6.0 CHARACTER OF INTRUSIVE NOISE DISCUSSION
The intrusive noise at the façade, and in particular the windows are to be designed, includes a significant level of low frequency noise. This energy can be seen on the attached charts in Appendix D between 63 and 200 Hz.
The attenuation characteristics of glass are such that the performance is lower in these frequencies than at higher frequencies. Higher Rw rating glass can be installed, and would perform slightly higher in the low frequencies, but also performs much better in the higher frequencies. This has the unintended effect of emphasising the low frequency noise level within the room as the overall noise level has been reduced.
Based on the 12mm laminated glass on-third octave band performance, the spectrum of the calculated noise level within the proposed bedrooms are shown in Appendix D.
The low frequency content of the calculated levels within the bedrooms are such that they are likely to be audible and annoying to occupants within the proposed apartments. It is considered likely that the neighbouring nightclub noise emissions will require reduction for noise levels within the proposed apartment to comply with the Town of Vincent Sound Attenuation Policy.
Given the noise emissions associated with the neighbouring nightclub have been conservatively estimated to significantly exceed the allowable noise levels in accordance with the Environmental Protection (Noise) Regulations 1997, a reduction in noise emissions from the nightclub would be considered a fair compromise.