LCQ9: Safety of glass protective barriers, glass panel external walls and glass curtain walls of buildings
Hong Kong (HKSAR) - Following is a question by the Hon Cheung Kwok-kwan and a written reply by the Secretary for Development, Mr Michael Wong, in the Legislative Council today (January 10):
Earlier on, a woman fell to her death after smashing, allegedly due to a loss of her footing, a glass protective barrier on the platform of a shopping centre. On the other hand, quite a number of operators of upstairs shops have in recent years replaced the external reinforced concrete walls or block walls of their shops with glass panel external walls in order to attract customers. Moreover, glass curtain walls have been used as external walls on quite a number of new type of residential buildings, or glass has been used as protective barriers on their balconies.
Regarding the safety of glass protective barriers, glass panel external walls and glass curtain walls of buildings, will the Government inform this Council:
(1) whether the use of glass protective barriers on building platforms and rooftops that exceed a certain height above ground level is prohibited under the existing legislation; if not, whether the authorities will, in the light of the aforesaid accident, enact the relevant legislation;
(2) of the number of unauthorised works of construction of glass panel external walls which were uncovered in each of the past five years by the authorities during routine inspections or upon complaints by members of the public; the districts in which such cases were mainly located, and the number of cases in which the persons concerned were convicted;
(3) whether the authorities have studied the durability of glass protective barriers, glass panel external walls and glass curtain walls, as well as the factors that may cause the glass of such structures to shatter abruptly;
(4) whether building owners are required under the existing legislation to regularly arrange authorised persons to check the conditions of the glass protective barriers, glass panel external walls and glass curtain walls of their properties; if so, of the details; if not, whether the authorities will enact the relevant legislation; and
(5) whether the authorities will conduct public education to remind building owners and managers to properly maintain the glass protective barriers, glass panel external walls and glass curtain walls of their properties; if so, of the details; if not, the reasons for that?
Construction of glass protective barriers, glass panel external walls and glass curtain walls of buildings are building works subject to the control of the Buildings Ordinance (Cap 123) (BO) and its subsidiary legislations. The material, design and construction of glass protective barriers, glass panel external walls and curtain walls are subject to the control of the Building (Construction) Regulations (B(C)R). The Buildings Department (BD) has also formulated relevant Practice Notes on "Curtain Wall, Window and Window Wall Systems" and "Protective Barriers" to provide comprehensive design and construction guidelines for practitioners.
In consultation with the BD, the Development Bureau provides the following reply to the five parts of the question:
(1) Under B(C)R, protective barriers should be provided where the level difference between the flat roof and roof of a building and the adjacent lower level is greater than 600 millimetres.
However, the prevailing legislation does not prohibit the use of glass as a material for protective barriers. Authorised Persons (AP), Registered Structural Engineers (RSE) and Registered Contractors (RC) should ensure that the material, design and construction of glass protective barriers comply with B(C)R and the safety standards specified in the Practice Note on "Protective Barriers". Specifically, according to B(C)R, all materials used shall be of a suitable nature and quality for the purposes for which they are used; adequately mixed or prepared; and applied, used or fixed so as to perform adequately the functions for which they are designed.
These requirements are applicable to glass protective barriers. The Practice Note also sets out in detail relevant requirements and standards, including design and construction of glass protective barriers as well as supervising the construction of the glass protective barriers by competent persons, to ensure the glass protective barriers installation works are carried out in accordance with the approved plans and are in compliance with the required standards.
(2) In the past five years, the numbers of removal orders issued by the BD against unauthorised glass panel external walls and convictions resulted from prosecution against non-compliance with such removal orders are tabulated below:
||No. of Removal Orders issued
of Convictions (note)
|2017 (January to November)
Note: The number of convictions does not necessarily correspond to the number of removal orders issued in the same year.
BD has not compiled the statistics of irregularities according to its geographical distribution.
(3) With regard to the glass protective barriers, the standards on quality control in Hong Kong are generally in line with the European and international standards. In its Practice Notes on "Curtain Wall, Window and Window Wall Systems" and "Protective Barriers", the BD requires the heat soak process conforming to the British Standard BS EN 14179-1:2005 be carried out on all tempered glasses to reduce a risk of spontaneous breakage induced by nickel sulphide contained in tempered glass. The Practice Note on "Protective Barriers" further requires that glass be used for protective barriers should comply with the impact test requirements for safety glazing materials.
The BD keeps the Practice Notes under regular review to seek improvement.
The BD has commissioned a consultancy study to review the existing requirements and standards on the material, design and construction of glass. The study is engaging the industry with relevant requirements and standards, and making reference to the experiences and practices of other countries with a view to formulating a set of requirements applicable to Hong Kong and meets the latest international standards.
(4) Building owners have the responsibility to ensure their properties are under proper maintenance and in safe condition, including the carrying out of regular inspection and timely repair. Owners shall as needed arrange regular inspections and repairs of their buildings and works inside their buildings.
Under the Mandatory Building Inspection Scheme (MBIS), the BD may serve statutory notices on owners of private buildings aged 30 years or above (except domestic buildings not exceeding 3 storeys) under BO, requiring them to carry out building inspection and repair found necessary.
The inspection covers external walls (including glass protective barriers, glass panel external walls and curtain walls) and should be conducted by Registered Inspector (RI). Where repair works are required, it should be carried out by RC under the supervision of RI.
In addition, the abovementioned Practice Notes also requires AP and RSE to offer appropriate assistance and advice to owners on regular inspection and maintenance of curtain wall, glass wall system, etc. as well as a maintenance manual.
(5) The BD regularly disseminates information to owners regarding building maintenance and repair through various channels including the BD's website and thematic website "Care for Your Building", pamphlets, promotional videos, mobile applications, exhibitions, promotional events and social media platforms to enhance public awareness on the importance of building safety and repair.
The BD also issues Practice Notes to provide guidelines on the maintenance, repair and inspection of curtain wall, window wall system, etc.
In addition, the BD regularly organises district briefing sessions to explain to owners on the details of MBIS and the importance of regular building inspection and repair. The BD also issues relevant code of practice, general guidelines and Practice Notes to provide detailed guidelines on the inspection and necessary repair works under MBIS to the public and the industry.
Published on: 2018-01-10
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