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LCQ2: Regulation of greening projects

     Following is a question by the Hon Tony Tse and a reply by the Secretary for Development, Mr Paul Chan, in the Legislative Council today (June 15):


     On the 20th of last month, the entire green roof of the Chan Tai Ho Multi-purpose Hall, covering an area of more than 1 000 square metres, at the City University of Hong Kong collapsed abruptly.  Some professionals have pointed out that accidents of such type are rare, and the roof being covered by green vegetation and thus being overloaded may be one of the causes of the accident.  The accident has aroused concerns among various sectors of the community about the regulation and maintenance of various types of greening projects (including rooftop greening projects) for buildings and related matters.  In this connection, will the Government inform this Council:

(1) of the main government departments which are responsible for the regulation of the construction, vetting and approval of works, works supervision, acceptance, maintenance and environmental protection-related issues, etc., of greening facilities/features (including green rooftops) for buildings, and the main ordinances regulating such matters; whether it conducted inspections of completed greening projects regularly in the past three years; if it did, of the details, including the number of staff members from various departments tasked with the inspection work, the number of inspections conducted by them, whether such inspections were carried out on a sampling basis, and the follow-up actions taken (including the respective numbers of verbal and written warnings issued and the number of cases in which prosecutions were instituted) each year; if it did not conduct any inspection, the reasons for that and whether it will do so; whether it has provided guidelines and practice notes on the maintenance and management of greening facilities/features for property owners and property management companies;

(2) as the authorities have indicated that there are different ways of handling and different arrangements for greening projects (including rooftop greening projects) for uncompleted and existing buildings, of the differences between the two in regard to vetting and approval of works, works supervision, acceptance and maintenance, etc. as well as the reasons for such differences, and whether the authorities will review and revise the relevant arrangements; and

(3) whether there is a requirement that greening projects for buildings (including rooftop greening projects) must be carried out under the supervision and monitoring of authorised professionals, and the acceptance of related works must be done by them; if there is such a requirement, of the types of professionals involved and whether they include landscape architects; if there is no such requirement, the reasons for that?



     Greening of buildings can bring many benefits on various aspects such as improving the environment and the ecology, saving energy, as well as enhancing people's quality of living.  In view of all these benefits, the Government has been striving to promote greening of buildings, including roof greening, vertical greening, sky gardens, terrace planting, etc.  Greening has a wide scope, and may be of very different forms, locations and scales.  Generally speaking, greening of buildings should pose no risk to safety, as long as it was suitably designed and constructed, and there are proper repairs and maintenance.

     My reply to the three parts of the question is as follows:

(1) With the paramount objective of ensuring building safety, the Government has in place different levels of regulatory control over the greening of private buildings.  If the greening only involves placing of a few flower pots, it generally will not cause any structural risk.  If the greening is of a substantial scale, the relevant owner should then consult authorised building professionals on matters such as loading of the building.  The building professionals authorised by the Buildings Department possess professional expertise.  They should advise the owners, where the greening involves building works, on the need for seeking the consent of the Buildings Department for the works taking into account their location, scope and scale.  For works requiring its prior approval, the Department will assess the proposed works in accordance with the Buildings Ordinance, and will only give consent to its commencement upon being satisfied of the safety of the works.  

     There are currently over 40 000 private buildings in Hong Kong, of which greening may be of varying scope and scale.  Therefore, the Buildings Department has not carried out inspections of the greening of buildings specifically.  Nevertheless, in view of the greened roof collapse incident at the City University of Hong Kong last month, the Buildings Department has been ascertaining through various channels any roof greening of large area in the territory that might have been carried out without prior evaluation by building professionals.  Immediate actions will be taken against any such case found.  In the course of its day-to-day handling of public reports on unauthorised building works and other matters and when conducting large-scale operation, the Buildings Department will take appropriate follow-up actions if any greening facilities which are unauthorised building works come to its attention.  But I must point out that owners of private buildings are responsible for the timely inspection and maintenance of their properties, including any of their greening facilities, to ensure their safety.  They should consult professional advice if in doubt.  

     Since the establishment of its Greening, Landscape and Tree Management Section in 2010, the Development Bureau has been formulating standards and guidelines on various types of greening, and particularly in relation to matters which schools should consider and consult professionals on when carrying out roof greening.  In addition, the Home Affairs Bureau has issued the Code of Practice on Building Management and Maintenance under the Building Management Ordinance to set out matters warranting the attention of owners' corporations and other building management bodies, including a chapter covering topics like roof/podium maintenance and repairs, e.g. dealing with water ponding, waterproofing, overloading or misuse of rooftops.  In view of the greened roof collapse incident at the City University of Hong Kong last month, the Buildings Department has issued notes on the provision of green roofs in school buildings to ensure safety of the premises and their occupants.  The Buildings Department has also issued a circular to the building industry, setting out and reminding practitioners of the existing provisions under the Buildings Ordinance applicable to roof greening.  The circular particularly reminds the relevant professionals and contractors of their duties to inform building owners of the actions to be taken during the design and construction of the greening facilities, the impact of greening on the structure of the subject building, and how to safely operate and properly maintain the relevant facilities after commissioning.  To enhance public knowledge of the relevant subject, the Buildings Department is drawing up a guide for property owners and the general public on the common greening works of buildings in Hong Kong.

     Furthermore, the Buildings Department and other relevant departments have arranged briefings for school administrators and other stakeholders to address their enquiries.  If necessary, the Buildings Department stands ready to brief other sectors concerned, such as property management companies, on the relevant matters.

(2) In principle, the same regulatory control with regard to building safety applies to greening irrespective of whether it was carried out during the construction or after the commissioning of the building.  For works requiring its prior approval, the Buildings Department will assess the proposed works in accordance with the Buildings Ordinance, and will only give consent to its commencement upon being satisfied of the safety of the works.  Greening of buildings, irrespective of when it was carried out, should pose no risk to structural safety, as long as it was suitably designed and constructed, and there are proper repairs and maintenance.

(3) For building works governed by the Buildings Ordinance, the property owners concerned must appoint registered professionals and contractors to carry out the works, irrespective of whether they are greening works or not, in accordance with the extant requirements under the Buildings Ordinance where applicable.  Broadly speaking, if the relevant works fall under Class II or Class III Minor Works (i.e. those of moderate or relatively low complexity), owners are required to appoint registered contractors to arrange the works to be carried out.  For Class I Minor Works (i.e. more complicated ones) and works that require prior approval from the Buildings Department, owners must also appoint an Authorized Person to be responsible for the preparation of building plans for submission to the Buildings Department and other relevant tasks such as supervision and testing.  Where structural details are involved, the appointment of a registered structural engineer is required for the preparation and submission of foundation plans or calculations to the Buildings Department.  Moreover, the Authorized Persons concerned should consult the advice of professionals from other related disciplines (such as landscape architects) having regard to the requirements of the actual works.

Ends/Wednesday, June 15, 2016
Issued at HKT 17:20


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