Page 82 - The Hong Kong Green Building Council (HKGBC) 香港綠色建築議會

Researches
Hong Kong is committed to building a green,
healthy and liveable city. Architectural
Services Department (ArchSD) is the works
agent for the development and up-keep of
Government facilities. It leads by example
through the implementation of sustainable
design concepts, and the adoption of green
procurement in its construction projects. The
Department collaborates with consultants,
contractors and industry stakeholders to
implement sustainable design in public
works projects and encourages its partners to
enhance sustainable construction practices
on site in addition to construction contract
requirements. As active members in various
advisory committees for sustainability and
green buildings, ArchSD also acts as an
advisor to the Government on environmental
sustainability in property planning and
development. Taking the reduction of
construction waste as an example, ArchSD
has implemented a number of sustainable
construction practices, which are outlined as
follows.
Prefabrication works carried out under a
factory environment lead to much better
quality products with generally less defective
products and material wastage, ultimately
saving valuable landfill capacity. The
Department has been applying prefabrication
in public works projects to a wide range of
construction processes, including structural
components, facades, staircases and dry-wall
partition construction.
80 HONG KONG REPORT ON THE STATE OF SUSTAINABLE BUILT ENVIRONMENT 2014
Role of Government in
Sustainable Construction
To strive for continual improvement in
environmental performance on its construction
sites, ArchSD also conducts the annual Green
Contractor Award Scheme in which public
works contractors are given the opportunity
to demonstrate innovative pollution controls
and environmental measures during
construction so that sustainability practices
and experiences can be shared amongst
participating contractors. Initiatives include
low-carbon bio-diesel as fuel for construction
plant and machinery, biological treatment
of waste water, innovative and effective
silencers, mufflers or acoustic shields for
percussive piling works, and vibratory jacking
or box-silenced percussion systems for
driving of sheet piles.
It is the Government's goal to minimise
construction and demolition (C&D) waste
and to promote recycling and the use of
recycled products as far as possible, to help
preserve the landfill and public fill capacities. as far as possible. All public works contractors
ArchSD vets building proposals in the early
planning stage to achieve a balanced cut
and fill design as far as possible to reduce
C&D materials at source. In addition, a C&D
material management plan is required for
any project generating more than 50,000 m3
of C&D materials or using imported fill in
excess of 50,000 m3. A good proportion of
C&D materials comprise broken concrete
and rock pieces, which can be recycled
into aggregates and granular materials for
use in construction works. The Department
has also been promulgating various green
specifications, such as the use of pulverised
fuel ash and ground granulated blast-furnace
slag in structural concrete, the use of recycled
aggregates in Grade 20 prescribed mix and
Grade 25 to 35 designed mix concrete, the
use of concrete paving units made of recycled
aggregates, and the use of Grade 200
recycled rockfill for hardcore layers. Selective
demolition and on-site sorting are adopted for
all demolition projects to facilitate recycling
are required to minimise generation of C&D
wastes at construction works and carry out
on-site sorting of the materials.