Passive design approach can include the structure of the building itself, including building orientation, window placement, skylight installation, insulation and building materials, or specific elements of a building, such as windows and window shades.
In ZCB, the various passive design measures lead to 20% energy saving compared to a similar building of the current standard design. Please click here for more details.
Cross-ventilation is a design to combat Hong Kong’s humid weather and make the building occupants comfortable. ZCB’s main facade faces southeast because the prevailing summer breezes come from that direction
A “wind catcher” resembling a small chimney is fitted to the roof at the centre of the building. Since the wind velocity at this opening is greater than it is at the lower windows of the building, air in the shaft is forced down to cool the building. Two wind catchers are installed to improve airflow further
In the hotter months, when mechanical cooling is in operation, the earth-cooling tube provides naturally pre-cooled air to reduce the cooling load and energy use
ZCB's elongated form enables a suitable room depth between the northwest and southeast facade for daylighting. A large glass wall on the northwest facade is positioned to face the relatively unobstructed sky, but is sheltered from direct sunlight
Light shelves on its southeast and northwest facades shade the periphery and distribute daylight furthest away from the windows
Light pipes are highly reflective tubes that capture light from domes on the roof. They help bring light to windowless areas inside the building
The glazing around the model exhibition area on the ground floor is fitted with movable heat reflecting shades behind the glazing. The shade with an aluminium sheet on one side emits radiant heat that is absorbed while allowing the diffusion of light
The concrete roof is covered with a thick layer of cellular glass insulation, screeding, and a protective surface membrane. Photovoltaic panels cover 85% of the roof area; the remaining 15% is covered by green roof
The high performance glass wall system offers good thermal and optical performance to lower cooling load, reduces the reliance on artificial lighting and hence reduce energy consumption. The reflecting shade inside the glazing achieves this by reflecting heat and reducing heat gain
ZCB's glazed external walls are protected by external shading of different types, varied to suit the different solar conditions on each side