Environment Experts call for green roofs

The Macau Association for Ecological Study has said that Macau should introduce green roofs in order to increase the green areas in the city.
Kou Lot Fu, president of the association, told TDM that the idea of green roofs, where trees are planted on the roofs of residential or commercial buildings, has existed in other Asian countries like Japan for a long time. He thinks that Macau can learn from those countries.
“The trees do not need to be big. They only need to be one to two meters tall. In fact, they can act as an effective heat shield”, he said.
Mr Kou reckoned that as long as there is good waterproofing and drainage design, as well as having enough soil, it is not difficult to plant trees on rooftops.
Another local environmental group, Green Future, suggested that the government could introduce the concept of green roofs to buildings on the future reclamation zones.
Scholar Richard Whitfield, who holds a PhD in Manufacturing Engineering, said that green roofs are a good idea to bring to Macau. In fact, he recalled that we already have a few examples of green roofs, although these are not conventional, since they have been installed in car parks instead of buildings.
To set up green roofs here, however, Dr Whitfield recalls that there is a need to have more expertise. Also, engineers and architects would need to be willing to take risks and explore a new field.
“In my experience, the biggest obstacle would probably be related to architects and engineers who are unfamiliar with this kind of technology and who are not willing to take risks,” he said.
IACM needs people who know how to install these types of roofs, as well as setting them up, as they have a complex structure, the scholar added. A number of matters should also be taken into consideration: “They have extra weight, so roofs need to be stronger. Then you have to have water sealant, and the structure is relatively complex, with the drainage. So it requires expertise to install them properly.”
Macau lacks expertise in this area, but the scholar thinks this will not prevent IACM from providing green roofs on Macau’s buildings, since there are experts in this area in both Hong Kong and Singapore, where the concept is quite developed.
Dr Whitfield said that IACM – if considering developing green roofs – should run training courses to enhance their staff’s skills.
The design of green roofs is another challenge, the scholar recalled. “Sometimes architects and engineers are quite resistant to change,” he said. In his opinion, “it’s a matter of education and training.”
Richard Whitfield thinks that tree plantation and watering also need to be improved.
“For example where I live Hac Sa Beach they’ve planted trees and I feel they’re very close together, they don’t have space to grow,” he said. Since a lot of trees are bought from China, the scholar worries about what kind of advice IACM staff is getting in Macau: “Are they giving them good advice on space between trees, on which type of trees would be more suitable and about the location?”
As Macau has recently adopted a sprinkler watering system for roadside plantations, Richard Whitfield suggested this should be conducted at nighttime. In his opinion, drip irrigation would be a better alternative.  CP/JPL