The first bio-engineered green roof that people can walk on opened yesterday at a school in Wong Tai Sin.
“The roof was a forbidden area used for placing water towers for traditional air-conditioning since 1982,” said Ho Sai-mun, principal of Lok Sin Tong Wong Chung Ming Secondary School. “I came up with the idea of redeveloping it into a place for students to use in 2002, and the construction was completed last year after obtaining permission from authorities, planning and collecting funds.”
The roof, named the Green, and the Garden of Friendliness, which is in the school playground and promotes organic community farming, will instill environmental protection concepts in students, Ho said. The Green, which cost about HK$2 million and took five years to build, will be used for science, technology, engineering, arts and mathematics learning.
The 1,938-square-foot roof uses the most advanced bio-engineering, achieving zero carbon emission and energy saving with features including a do-it-yourself module standalone system, fertile sand-based turfing and solar water compensation tank.
“The Green is sustainable and low maintenance in that it mainly uses rainwater as the water source, artificial irrigation is minimal and its rainwater collection system eliminates the need for an electrical pump,” said Brian Cheng Leung- yan, the engineer who volunteered to design the roof. “The Green is walkable because of its specially designed base that provides support. The grass can grow better with more stamping, with more space it creates in the ground for fertilizers to seep through.
“Students can monitor the temperature change and water usage by the digital temperature monitoring device and water usage monitoring device. The water usage is so low that it can hardly be recorded.” Secretary for the Environment Wong Kam-sing, a guest at the opening ceremony, said it was time to take action after understanding the concept of sustainability, and to reduce waste to combat climate change.
“We need to change our lifestyle to a low-carbon one and reduce waste and energy consumption,” he said. “The school is a good platform for practice. We launched the `Wasteless School’ Campaign in 2014 to encourage the reduction of waste at school.”