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BEAM P
LUS FOR
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UILDINGS
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ITE
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SPECTS
(S
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V
ERSION
1.2
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A
8 M
ICROCLIMATE
A
ROUND
B
UILDINGS
Copyright © 2012 BEAM Society Limited. All rights reserved.
Page 46
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ITE
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SPECTS
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LANNING AND
D
ESIGN
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8 M
ICROCLIMATE
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ROUND
B
UILDINGS
E
XCLUSIONS
SA 8a – Sites which are located in urban zones with existing stagnant air
O
BJECTIVE
Ensure the microclimate around and adjacent to buildings has been
adequately considered, and where appropriate, suitable mitigation
measures are provided.
C
REDITS ATTAINABLE
4
P
REREQUISITES
For Air Ventilation Assessment (AVA), those project belonging to the
categories requiring AVA as specified in the Housing, Planning and
Lands Bureau (HPLB) Technical Circular No. 1/06 – Air Ventilation
Assessment.
C
REDIT REQUIREMENT
a) Wind amplification
1 credit for demonstrating that no pedestrian areas will be subject to
excessive wind velocities caused by amplification due to the site layout
design and/or building design.
b) Elevated temperatures
1 credit for providing shade on at least 50% of non-roof impervious
surfaces on the site (parking, walkways, plazas) using light coloured
high-albedo materials (albedo of at least 0.4).
1 credit for providing roof material that meets the Solar Reflectance
Index (SRI) of 78 or vegetation roof covering at least 50% of the total
roof area.
c) Air Ventilation Assessment
1 credit for conducting an AVA by wind tunnel or Computer Fluid
Dynamics (CFD) according to the prevailing AVA methodology
introduced by the Government demonstrating the optimal option is
selected in comparing with different options.
A
SSESSMENT
The microclimate around buildings includes commonly and frequently
accessible areas, such as entrances and exits to buildings, pedestrian
routes, opening spaces, streets, podium gardens, walkways, sitting-out
areas, playground areas, etc.
a) Wind amplification
The Client shall submit a report prepared by a suitably qualified person,
using either wind tunnel tests or CFD studies, demonstrating compliance.
The assessment should be based on the following key approaches:
Assessment area where test points are positioned is within 1H (H
being the height of the tallest building on the project site) from the
site boundary;
Relative wind speeds around buildings shall be assessed by placing
a suitable scale model of the building and surrounding large
structures within radius of 2H (building height) of the tallest building
from the development site in a boundary layer wind tunnel, if there
are prominent features (e.g. tall buildings or large and bulky
obstructions) immediately outside the 2H zone, the assessment
boundary should be extended to include these prominent structures;