LC Urgent Q4: Immediate inspection of greened roofs

Following is an urgent question by the Dr Hon Helena Wong under Rule 24(4) of the Rules of Procedure and a reply by the Acting Secretary for Development, Mr Eric Ma, in the Legislative Council today (May 25):


On the 20th of this month, the entire roof of the Chan Tai Ho Multi-purpose Hall at the City University of Hong Kong collapsed abruptly, injuring three persons. The accident has aroused public concern about the building safety issues that may arise from roof greening works. In this connection, will the Government inform this Council whether it will immediately deploy manpower and resources to inspect the greened roofs (including those with vegetation cover) of buildings such as hospitals, cultural/recreational/sports facilities and exhibition halls across the territory, so as to ascertain the structural safety of such roofs; if it will, of the details of the inspection work and how the inspection findings will be made public; if not, the reasons for that?



With regard to the facilities mentioned by Dr Hon Wong, the Architectural Services Department (ArchSD) attaches great importance to building safety at the design stage and during the subsequent maintenance and repairs of roof greening works for which it is responsible. At the design stage, regardless of whether the roof greening works are carried out during construction of the new facilities or after completion of existing ones, the ArchSD will carefully consider factors such as the rooftop space, structural loading capacity, drainage and leakage proof with a view to ensuring safety on all fronts before commencement of works. At the post-commissioning stage, for government properties under its charge, the ArchSD will carry out regular preventive maintenance and investigation, and any issues discovered will be followed up at once.  Moreover, the management offices of the property users will clear the rooftop drainage ducts during its routine inspections to prevent any water from accumulating due to blocked drains which will increase the roof loading. If departments have detected any abnormal situations with their buildings, they will immediately report to the ArchSD, which will deal with the situation as soon as possible according to the nature of the reports.

Among the facilities of which the ArchSD is currently responsible for their construction and maintenance, those having conducted roof greening are mostly reinforced concrete structures, which have a relatively higher roof loading capacity in general. Coupled with the fact mentioned above that the ArchSD has fully considered the safety factor at both the design and maintenance stages, the ArchSD is of the view that the green roofs of which it is responsible for their construction and maintenance will not constitute any apparent risks. That said, in view of this roof collapse incident, as I mentioned in my reply to Members' questions just now, the ArchSD will carry out full inspections of government facilities, with a view to assuring the safety of the users and the public. During the inspections, the ArchSD will confirm the conformity of the facilities to their original designs, their proper maintenance, and if there are any irregularities in the building.

Based on its risk assessment, the ArchSD has given priority to inspecting greening facilities above long-span metal structures. Inspections of all the four facilities of this sort in Hong Kong were completed, and their overall conditions were found to be entirely normal. Thereafter, the ArchSD will progressively inspect the other concrete facilities, covering both green roofs retrofitted after the commissioning of the buildings concerned, as well as those installed when the buildings were constructed. The ArchSD will follow up immediately on any issues discovered during the inspections.

Ends/Wednesday, May 25, 2016
Issued at HKT 19:46