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BEAM PLUS FOR NEW B UILDINGS APPENDICES
V ERSION 1.2 8.8 PASSIVE DESIGN ASSESSMENT METHODOLOGY
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8.8 PASSIVE
DESIGN
ASSESSMENT
METHODOLOGY
8.8.1 BUILDING PASSIVE D ESIGN
8.8.1.1 Site Planning
8.8.1.2 Building Orientation
8.8.1.3 Building Envelope
8.8.1.4 Natural Ventilation
8.8.1.5 Daylight
8.8.2 Active Building System
8.8.2.1 HVAC System in Common Areas
8.8.2.2 Artificial Lighting System in Common Areas
8.8.2.3 Vertical Transportation System in Common Areas
8.8.1.1 Site Planning Site Planning
Site planning with respect to building massing has a significant effect on wind
flow across the site and downwind of the site – it is a neighbourhood feature,
not necessarily a site feature, however, it is included here to ensure the
development in question is a benefit to the community.
Building separation is a fundamental contributor to wind flow across a built up
site, larger building separation generally enables better wind flow across a site.
The Sustainable Building Design Guidelines (SBD) [1], which are set out in
APP 152, have prescriptive requirements for building separation.
The prescriptive assessment of building separation is to be carried out in
accordance with the methodology set out in APP 152. This quantifies the gaps
between or the “permeability” of the buildings as a percentage of the total
building frontage.
To gain the second credit only, If the practitioner feels this method does not
adequately represent their situation, they can carry out a performance
assessment, in line the AVA methodology [2]. This compares a notional base
case having a building permeability of 33% and the proposed design case.
The assessment shall be carried out in the following way:
1. The model and domain shall be set up as per AVA methodology.
2. Different to the AVA assessment, the measurement plane shall be taken at
the half the average building height.
8.8.1.2 Building
Orientation
The solar environment of Hong Kong determines that different facade
orientations will be exposed to different levels of solar irradiation. This in turn
will affect the energy required to condition internal spaces.
Residential developments, conditioned from April to October inclusive, have an
average solar irradiation of 395 kWh/m2/(Apr-Oct). The peak solar irradiation
occurs towards the west.
The solar irradiation (incident solar power) for the design shall be calculated as
follows:
 Solar irradiance calculated over the period from 1st April to 31st October
1 Buildings Department PNAPP152 - The Sustainable Building Design Guidelines.
2 HPLB Technical Circular No. 1/06.