The Housing Authority (HA) has employed a variety of "green enhancement oriented" methods in the design and construction of the Sau Mau Ping South Estate.

"Through planning, design, construction and working with tenants, the Housing Authority encourages healthy and harmonious living in a sustainable community," says Michael Choi, a senior architect at the HA who was in charge of the Sau Mau Ping South Estate project, one of two Grand Award winners in the new buildings category (Hong Kong) of the Green Building Award 2010.

Choi says they used computer software on micro-climate studies to reduce solar heat gain and maximise lighting and ventilation of the site indoors and out.

"We also used the software to improve the ventilation of the typical lift lobbies and corridors by setting the opening angles of the windows and introducing a wind scoop on the roof top," he says. "The depth of the window overhangs was adjusted based on their orientation to enhance daylight performance of the flats. Tinted glass was used for west-facing units to cut solar heat gain."

The project has achieved an average wind speed of three to five metres per second along the central pedestrian spine, enabling the generation of wind power. A vertical wind turbine and six solar-and-wind hybrid lighting systems were installed to power lights for an outdoor 850-square-metre area.

The HA has adopted the "standard modular flat assembly" approach to cut building costs, improve features and boost floor sizes. To preserve trees, slopes were stabilised without removing existing loose soil and shrubs. As a result, more than 110 trees have been preserved on the slopes of Sau Mau Ping. There is also a lot of vertical greening, and greening on rooftops, low-rise buildings and covered walkways.

Sau Mau Ping South Estate is the last phase of the Sau Mau Ping redevelopment programme, launched by the government in 1987. It provides 3,995 flats for about 11,000 residents.