LCQ14: Safety of Windows and Curtain Wall

Following is a question by the Hon Claudia Mo and a written reply by the Secretary for Development, Mr Paul Chan, in the Legislative Council today (December 5):


It has been reported that in September this year, a huge window pane of an upper floor unit at The Arch, a luxury residential project in West Kowloon, cracked suddenly, and the glass shards falling from height injured a passer-by.  According to the report, a total of over 30 pieces of window panes had fallen from units in that estate since 2007, posing threat to the safety of the residents in the area and passers-by, and such situation has aroused concerns.  It has also been reported that the safety standards in respect of window panes formulated by the Buildings Department are far lower than those in certain European countries.  Moreover, the fact that incidents of window panes of residential units cracking and falling occur from time to time reflects that the problem of "glass cancer" is serious, which poses threat to public safety.  In this connection, will the Government inform this Council:

(a) of the number of reports received by the authorities in the past 10 years on incidents of cracking or falling of window panes of major housing estates or buildings aged below 10 years and the resultant casualties, with a breakdown by age of the building and cause of the incidents; whether they have taken follow-up actions and instituted prosecutions; if they have, of the number of prosecutions instituted and other details; if not, the reasons for that;

(b) whether it has reviewed the adequacy of the number of buildings selected each year for mandatory inspection of windows under the existing Mandatory Window Inspection Scheme (MWIS); as incidents involving the cracking and falling of window panes of newly built buildings have occurred from time to time, whether it will consider including private buildings aged below 10 years in MWIS; and

(c) whether it has any plan to step up regulation of the design and construction of glass curtain walls and enact legislation stipulating that the contractors concerned will be held liable in case of accidents; if it has, of the details; if not, the reasons for that?



The Buildings Ordinance (BO) aims to regulate the planning, design and construction of buildings and associated works on private land and, for this purpose, to prescribe building standards regarding safety, sanitation and the environment.  In accordance with the provisions of the BO, any person intending to carry out building works is required to appoint an authorised person (AP) and, where necessary, a registered structural engineer (RSE) to prepare and submit building plans for approval by the Buildings Department (BD), unless the works fall within the scope of designated minor works that can be carried out under the simplified requirements of the Minor Works Control System or such works are exempted works.  The person must also appoint a registered contractor to carry out the works in accordance with the approved plans.  After the building plans have been approved, the AP must obtain written consent from the BD before commencement of works.  The material, design and construction of windows and curtain walls are subject to the control of the Building (Construction) Regulations (B(C)R).  The BD has also formulated relevant Practice Notes on "Curtain Wall, Window and Window Wall Systems" and "Aluminium Windows" to provide clear design and construction guidelines for industry practitioners.

The standards on quality control of glass (such as tempered glass) in Hong Kong are generally in line with the European and international standards.  In its Practice Note on "Curtain Wall, Window and Window Wall Systems", the BD requires the heat soak process conforming to BS EN 14179-1:2005 should be carried out on all tempered glass to reduce the risk of spontaneous breakage induced by nickel sulphide inclusions in tempered glass.  The requirement complies with the European Standard EN 14179-1:2005.  In fact, the BD always makes reference to relevant international standards and experience in setting safety standards in private buildings.

My reply to the three-part question is as follows:

(a) Regarding private buildings, the BD has only started maintaining records on reports relating to window falling off with the frame from buildings since October 2004.  There is however no statistics on cases involving only the breakage of window pane, or analysis on the type or age of buildings involved.  According to the relevant records, as at September 30, 2012, a total of 233 cases of window falling off with the frame from private buildings had been reported.  The said cases resulted in one death and 22 injuries.  The BD does not have the other statistical information on these cases as required in the question. 

In addition, according to the records of the Housing Department as at the end of September 2012, there were seven cases of falling windows reported for Home Ownership Scheme courts in the past 10 years.  The age of the courts involved ranged from about 15 years to 25 years. 

(b) The BD fully implemented the Mandatory Building Inspection Scheme and the Mandatory Window Inspection Scheme (MWIS) on June 30, 2012 to tackle the problem of building neglect at source.  The MWIS covers all private buildings aged 10 years or above, except domestic buildings not exceeding three storeys in height.  Building owners are required, within a specified timeframe, to appoint a qualified person (QP) to carry out a prescribed inspection and to appoint a registered contractor to carry out a prescribed repair found necessary of the windows once every five years.  The prescribed repair must be carried out under the supervision of a QP.  Each year, the BD will arrange to select a total of 5,800 buildings aged 10 years or above for the MWIS.  The target buildings selected each year will include a mix of buildings in different conditions and age profiles in different districts.  The BD is now issuing statutory notices to the first quarterly batch of target buildings selected for the MWIS.

In formulating the requirements of the MWIS, the Government conducted a two-stage public consultation in 2003 and 2005.  The target groups included various sectors of the community and major stakeholders (including owners, professional bodies and the building industry).  In respect of the MWIS, the community consensus obtained in the consultation was that the scheme should apply to private buildings aged 10 years or above, and that the inspection cycle should be five years.  As the MWIS is now at its initial stage of implementation, we have no plan to revise the building age requirement under the scheme at this moment; but we will keep the effectiveness of the scheme under review having regard to the experience gained.  We also encourage owners to carry out inspection and repair for their buildings voluntarily where necessary to ensure good maintenance and safety conditions of buildings.  Besides, the BD has through publicity educated the public on proper usage of windows and the importance of regular maintenance and repair.

(c) As mentioned above, in accordance with the BO, except for minor works or exempted works, any person intending to carry out building works is required to appoint an AP and/or a RSE to prepare and submit building plans to the BD for approval, and to appoint a registered contractor to carry out the building works according to the approved plans.  Prior consent from the BD is also required before commencement of works.  Moreover, to ensure that any building works in progress are in compliance with the law, BD staff will monitor and inspect active work sites regularly.  APs, RSEs and registered contractors all have the statutory obligation to coordinate, supervise and carry out the building works, and are required to submit test reports to ensure that the quality of their works complies with the BO.  Before issuing the occupation permits, the BD will conduct final checks on the test reports on construction materials or components as well as the completed works.

APs, RSEs and registered contractors should ensure that their works in terms of material, design and construction of windows and curtain walls comply with the B(C)R and the safety standards specified in the two Practice Notes issued by the BD as mentioned above.  According to the B(C)R, all materials used in any building works or street works 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 windows and curtain walls installed in buildings.  The Practice Notes set out in detail such relevant requirements and standards as material, design, installation as well as testing of windows and curtain walls.  Besides, registered contractors are required under the Practice Notes to have experienced and skilled supervisors and workers, and to put in place suitable quality assurance procedures to ensure the proper installation of the windows and curtain walls. 

Any person or contractor who contravenes the above requirements may breach certain provisions of the BO, such as sections 40(1AA) and 40(2A)(a).  According to section 40(1AA) of the BO, any person who knowingly contravenes section 14(1) (i.e. the requirement of obtaining the prior approval of plans and consent for commencement of works from the BD) shall be liable on conviction to a fine of $400,000 and imprisonment for two years; and to a fine of $20,000 for each day during which it is proved to the satisfaction of the court that the offence has continued.  Besides, any person who contravenes section 40(2A)(a) of the BO shall be liable on conviction, in the case of building works (other than minor works), to a fine of $1,000,000 and imprisonment for three years; or in the case of a prescribed inspection in respect of a window in a building or minor works, to a fine of $500,000 and imprisonment for 18 months.

The BD keeps the Practice Notes under regular review to seek improvement.  The abovementioned Practice Notes on "Curtain Wall, Window and Window Wall Systems" and "Aluminium Windows" were last revised in May 2012 and March 2006 respectively.  To meet the evolving needs of the community, the BD just commissioned a consultancy study in November this year to review the existing requirements and standards on the material, design and construction of glass, and windows and curtain walls will be included in the study.  The study will also make reference to the experience and practices of other countries to ensure that the requirements keep up with the latest international standards.

Ends/Wednesday, December 5, 2012
Issued at HKT 15:17