How green is your footprint?

PUBLISHED : Tuesday, 12 March, 2013, 12:00am
UPDATED : Tuesday, 12 March, 2013, 10:13am

The Construction Industry Council is set to launch a system for rating the carbon footprint of construction materials.

Thomas Ng Shiu-tong, a University of Hong Kong engineering professor involved in devising the scheme, says it will be the first of its kind.

"So far there haven't been any agreed methods for evaluating the carbon footprint of construction materials," he says.

The scheme rates six types of construction material - cement, aluminium, glass, ceramic tiles, rebar and structural steel - on a five-grade system.

The system takes a cradle-to-site approach to calculating the carbon footprint of the materials, Ng says.

"Greenhouse gas emissions produced from the extraction of raw materials, manufacturing and transportation of the construction materials to Hong Kong are all included.

"The carbon footprint left by different construction materials varies a lot. The same type of material manufactured on the mainland and in Italy leave different carbon trails due to the difference in techniques adopted by manufacturers and transportation involved in exporting them to Hong Kong. The labels can help the industry know which materials are more environmentally friendly."

A life-cycle approach to monitoring carbon emissions from buildings should be a future trend, Ng says.

"The Hong Kong Housing Authority is a pioneer. For some new public housing projects, including the one in Kai Tak, they set the life cycle of the buildings at 100 years. From the procurement of materials, building of the residential estates, operation of the buildings up to the demolition of the estates and the subsequent transportation of waste materials to landfills - the whole carbon cycle is calculated."