The remains of a green rooftop that collapsed at City University's Kowloon Tong campus, May 20. The collapse has prompted concerns about the risk of overloaded roofs at educational institutes across Hong Kong. (Photo by AFP)
After the collapse of a Hong Kong university's rooftop garden, many Catholic schools and parishes in the territory are confident that their own gardens are safe.
The collapse of a 1,400 square meter rooftop garden at the City University of Hong Kong injured three people May 20 and prompted officials to urge education institutions to conduct extensive safety checks on their rooftop gardens.
After the accident, building officials also asked schools who have yet sought approval for their garden to contact the education bureau to register for a review.
Sister Magdalen Siu, principal of the Holy Family Canossian School (Kowloon Tong) said that she thought that safety was more of an issue with small-scale projects "since they don't need any approval."
Holy Family Canossian School has a 400 square meter rooftop garden, which was built in 2011.
"Our garden went through a very rigorous approval process with the authorities," Sister Siu told ucanews.com. "The construction only took two months but it took one and a half years to get approved," she said.
Part of the rooftop greenery at Caritas Lok Kan School. (Photo by Caritas Lok Kan School)
Rooftop gardens have become popular campus greenery projects and schools built after 2000 have set aside additional loading capacity for a rooftop garden.
Turning rooftops into gardens for planting vegetables has also become a welcomed green initiative in some parishes. This has been especially so after Pope Francis' first encyclical on the environment — Laudato Si', which is past its first anniversary on May 24.
The Holy Cross Church established an environmental group to promote the message of the encyclical and they have planned a rooftop garden in response to the Pope's appeal that "neighborhoods, even those recently built, are congested, chaotic and lacking in sufficient green space."
"Our church building is old. So we have to consider the loading and the maintenance," said Joe Chan, a member of the parish group.
The group sought consultancy from the Catholic Messengers of Green Consciousness, an organization that promotes environmental protection in the diocese.
Among the advice they got was to consider the surface area of the roof and to understand its loading capability.
"We are a bit different from the City University's approach. They just let the soil cover the rooftop but we use containers to hold the soil for planting," said Leung Chi-wan, a former engineer and a member of Catholic Messengers of Green Consciousness.
Having the rooftop covered with soil directly will make rainwater more difficult to drain and the roots could damage the building structure, he said.
Ivan Ho, chair of the Professional Green Building Council and board member of the Hong Kong Institute of Architects, told the South China Morning Post that 99.9 percent of rooftop gardens in Hong Kong are safe.
Pot plants at Caritas Lok Kan School’s rooftop garden. (Photo by Caritas Lok Kan School)
