Our Sustainable Practices

 Case Study One – Hong Kong Wetland Park

The Hong Kong Wetland Park occupies 61-hectares of land and is located on the north-eastern edge of Tin Shui Wai in the New Territories in Hong Kong. The Park is envisaged as a prime example of harmony of human and nature, of environmental practice and sustainable development. It is unique to Hong Kong , which seeks to serve different purposes, such as conservation, tourism, education and recreation, all with equal importance.

Special features are incorporated in the design of the buildings to cater for the purpose of integrating man-made structures with the natural environment in the park. These unique features include landscaped roof, timber cladding and multiple layers of shades. The Visitor Centre with a footprint of approximately 10,000 square metre provides integral facilities to visitors, including three major Galleries, Resource Centre, Office, Café, Shop, Play area and Toilets. The Satellite Building and three Bird Hides are located in the outdoor area. Each facility serves unique functions for conveying wetland messages.

There are ten fundamental green concepts embedded in the development which are summarised as follows:

 

 

 

 

 

 
1. Low Overall Thermal Transfer Value (OTTV)
 
  • The Green Roof and the orientation of the building allow the Visitor Centre envelope to achieve energy efficiency performance of approximately OTTV 16W/m2.
2. Geothermal Heat Pump Air-conditioning System
 
  • A Geothermal Heat Pump Air-conditioning System is installed at the Visitor Centre. It utilises the mass earth of the park for heat exchange to keep the park environment quiet and undisturbed. This system is energy efficient and environmentally friendly.
  • Approximately 468 units of 32mm-diameter flow and return high-density polyethylene (HDPE) pipes are buried underground at 50m deep and embedded in bentonite clay and cement grouting for heat exchange with the constant underground temperature. This system is capable of providing approximately 390 tonnes of air-conditioning per day.
  • This method eliminates the use of visible and noisy heat dissipation air-conditioning equipment, reduces external louvers, and precludes direct heat dumping into the environment which is particularly favourable and suitable for the environment of wetland park.
3. Natural Lighting / Ventilation and Renewable Energy
 
  • Skylights are installed at the Atrium (north light) and external toilets to allow the use of natural light. External artificial lighting is minimised to reduce power consumption.
  • Natural ventilation is implemented by means of elevated windows at the Satellite Building.
  • Other energy efficient and saving features adopted in the Building Services design include photovoltaic panels for oscillating fans in Bird Hides, T5 fluorescent tubes with electronic ballasts, occupancy sensors for office lightings, CO2 sensors for fresh air supply, wind sensors for toilet ventilation, photo sensors for the lighting system in the Atrium, rain sensors for the automatic irrigation system, the Variable Voltage Variable Frequency (VVVF) drive for the lift installation and the variable speed drive for condensing water pumps etc..
4. Ramp Access
 
  • Circulation ramps are built throughout G/F and 1/F galleries at the Visitor Centre to facilitate the access of disabled visitors and minimise the use of mechanical lifts.
5. Minimised Water Consumption
 
  • Low capacity, 6-litre water closets are used to reduce water consumption for toilet flushing.
  • The design of the Satellite Building is tailored for collecting rainwater as flushing water.
  • Recycling of lake water for a water feature cuts down water consumption.
6. Recycled Brick Wall and Fenders
 
  • Recycled Chinese bricks are used for building a brick wall on the south face of the Visitor Centre and the Ticket Office to minimise the effects of solar gain to the building.
  • Timber fenders are re-used in the freshwater marshes to serve as resting posts for habitats.
7. Shading by Timber Screens
 
  • Sustainable timber from identified renewable sources is used throughout the whole project as vertical and horizontal louvers to provide shading for the buildings and external landscaping work.

8. Recycled Aggregates and PFA
 
  • A total of 15,300 tonnes of recycled aggregates/rock fill are used as sub-base, hardcore and fill materials in the development together with 5,600 tonnes of recycled coarse aggregates in the structural concrete.
  • The majority of the recycled aggregates are generated from a nearby recycling plant. 75% of the total amount of structural concrete used by volume contains recycled aggregates or PFA as partial cement replacement.
9. Re-use of Existing Materials
 
  • Existing materials used at the Phase 1 and Phase 2 site, such as recycled granite paving, was originally from the wall of the Hong Kong Police Headquarters, Chinese bricks were recycled from the demolished old houses in a Chinese Village, and oyster shells were sourced from the nearby Lau Fan Shan oyster farm.
  • The existing Phase 1 Visitor Centre has been converted into a new Ticket Office, some of the aluminium wetland habitat sculptures will be relocated to Phase 2 site. Also all existing trees and many other plants from the Phase 1 site are preserved within the Phase 1 site or transplanted to the Phase 2 site.
10. Soft Landscape Species
 
  • Native plant species, which require less maintenance and irrigation, are used extensively in landscaping work.