132003.221132 (23616DA) - Doonella Estate - Road Traffic Noise Assessment Report

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7.1 Architectural Treatments

Noosa Shire Council has indicated that the preferred option for noise amelioration at allotments
which exceed the external noise level limit of 60 dB(A) Lio (18 hour) | metre from the building
facade is to incorporate architectural treatments into the facade of proposed buildings to comply with
the internal noise criteria in shown in Table 4.1.

The external 60 dB(A) Lio (18 hour) noise level criterion | metre from the building fagade would be
exceeded for the ground floor of residences located on allotments 159 - 171, 175 and 177 - 181
and the first floor of residences located on allotments 159 — 171 and 174 — 181. Architectural
treatments would be required to meet the internal noise level goals, from Table 4.1, at these
allotments.

The level of noise control required for the habitable rooms of the residences were assessed with
respect to Australian Standard AS3671 - 1989 ‘Acoustics - Road traffic noise intrusion - Building siting
and construction”.

The recommended internal noise level for bedrooms is 40 dB(A) and for recreational areas is 45
dB(A), as stated in AS2107-2000 entitled “Acoustics-Recommended design sound levels and
reverberation times for building interiors”. Using the methodology contained in AS 3671-1989
“Acoustics — Road traffic noise intrusion — Building siting and construction” the required Traffic Noise
Reduction TNR construction category for residences that exceed the external noise level criteria of
57 dB(A) Lto (18 hour) was determined in accordance with Section 3 of the Standard. Table 7.1
contains the TNR and construction category for residences that exceed the external noise level
criteria of 60 dB(A) Lio (18 hour} noise level criterion | metre from the building facade.

The Standard AS3671 contains the following definition for the construction categories.

Category |. Standard construction; openings including open windows and doors may comprise up to
10% of the exposed facade. TNR of approximately 10 dB(A) is expected.

Category 2. Standard construction, except for lightweight elements such as fibrous cement or metal
cladding or all-glass facades. Doors, windows and windows must be closed. TNR of approximately 25
dB(A) is expected.

Category 3. Special construction, chosen in accordance with Clause 3.4. Windows, doors and other
openings must be closed. TNR between 25 and 35 dB(A) is expected.

Category 4. TNR greater than 35 dB(A) is required; special acoustic advice should be sought.

The -maximum predicted external Leq(|hour) noise levels described in Table 5.3 are used to
determine the necessary noise reduction required from the facade nearest to Beckmans Road by
subtracting the AS2107 internal noise level goals of 45 dB(A) for living areas and 40 dB(A) for
bedrooms from the maximum predicted external Leq(|hour) daytime and night time noise levels
respectively.

The necessary noise reduction is achieved by incorporating architectural treatments with the
appropriate Rw ratings into the facade of the building. Rw is the weighted sound reduction index and
basically equivalent to the previously used STC (sound transmission class index). The calculated traffic
noise reduction (TNR) required to achieve internal noise goals for residences that exceed the
external noise level criteria of 60 dB(A) Lie (18 hour) noise level criterion | metre from the building
fagade is shown in Table 7.1.

3052R01VO3.doc Proposed Residential Subdivision Beckmans Road, Tewantin Lensworth Lake Doonella Pty Ltd c/- PMM Group Pty Page 12

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