Following is a question by the Hon Kingsley Wong and a written reply by the Secretary for Housing, Ms Winnie Ho, in the Legislative Council today (October 8):
 
Question:
 
     I often receive complaints and requests for assistance from residents of public housing estates (PHEs) about the spalling of mosaic tiles on the external walls of buildings, and it was reported that there were occasional accidents of members of the public being injured by spalled mosaic tiles detaching from the external walls of buildings. In this connection, will the Government inform this Council:
 
(1) of the list of PHEs where mosaic tiles have been used as a major building material for external walls;
 
(2) of the number of cases of mosaic tiles spalling (on external walls, walls of lift lobbies and corridors, etc) in PHEs over the past three years and, among such cases, the number of those resulting in injuries to passers-by, as well as the estates involved in such cases (including the names of blocks) and their block types (e.g. Trident, Harmony, and Concord), their years of completion, and the causes of the spalling of mosaic tiles on the external walls;
 
(3) given that the spalling of mosaic tiles will also occur at locations such as walls of lift lobbies and corridors in PHEs, whether the Government has measures in place to ensure the safe entry and exit of residents, such as arranging professionals to carry out regular checks and timely repairs;
 
(4) whether it will conduct a general survey on the conditions of mosaic tiles in older PHEs (e.g. those aged 30 years or above) to facilitate early repair works, thereby safeguarding public safety; if so, of the details; if not, the reasons for that; and
 
(5) of the main reasons for using mosaic tiles as a material for the walls of buildings (including external walls, walls of lift lobbies and corridors) in PHEs; whether it will consider reducing the use of mosaic tiles and choosing other building materials that are equally aesthetic and practical but safer?
 
Reply:
 
President,
 
     The Hong Kong Housing Authority (HA) has always placed great emphasis on building safety. Through daily inspections and various inspection and maintenance programmes, public housing estates receive timely and proper maintenance and repairs to ensure they remain in good condition.
 
     In response to the question raised by the Hon Kingsley Wong, our reply is as follows:
 
(1) Currently, there are 128 public housing estates under the HA using mosaic tiles as the exterior wall finishing materials. Please refer to Annex I.
 
(2) The Housing Department (HD) conducts daily inspections of the common areas and facilities within public housing estates, including lift lobbies and corridors, to maintain facility safety and environmental hygiene. Upon identifying facilities requiring maintenance during inspections (such as spalling of mosaic tiles) or receiving reports from tenants, the HD would promptly arrange repairs. According to our records, there were a total of 23 cases of spalling of mosaic tiles on the external walls, with three cases involving minor injuries to pedestrians from January 1, 2022 to August 31, 2025. The estate offices took immediate follow-up actions, including cordoning off the affected passageways, inspecting other sections of the external walls, and arranging repairs. All cases were fully resolved. In general, mosaic tiles on external wall may spall due to ageing or environmental factors, such as change in temperature and humidity, but this does not affect the overall structural integrity of the building. For details of the aforementioned cases involving spalling of mosaic tiles from external wall, please refer to Annex II.
 
(3) and (4) The HD has been conducting daily inspections and implementing professional maintenance and repair programmes across all public housing estates in Hong Kong. Based on factors such as the age and structural condition of buildings, timely inspections and repairs are arranged to ensure structural integrity and safety, thereby providing residents with a secure and comfortable living environment. The relevant work mainly includes the following:
 
(i) Daily Inspections: Covering all public housing estates regardless of building age, frontline staff conduct daily inspections of buildings and communal facilities, following up on items requiring repair in a timely manner;
 
(ii) Annual Technical Inspection: Each estate undergoes an annual review to establish a yearly maintenance plan, which includes inspection and upkeep of public facilities (e.g. fire doors, floor tiles, external walls, etc) and equipment (e.g. lifts, fire safety installations, pipelines, etc) to enhance efficiency and safety standards;
 
(iii) Total Maintenance Scheme: Proactive inspections are conducted for public rental housing aged 10 years or above. During these inspections, attention is also given to the condition of external walls near the flats. If external wall repairs are identified, appropriate follow-up actions will be taken. This approach not only improves tenants' living environment, but also extends the service life of the flats;
 
(iv) External Wall Finishes Repair Programme: For older public housing estates (e.g. those aged 30 years or above), the HD arranges external wall inspections and repairs as needed to enhance the safety and durability of external walls; and
 
(v) Comprehensive Structural Investigation Programme: Detailed structural safety assessments are conducted for public housing estates approaching or exceeding 40 years of age. These assessments verify the structural safety and evaluate the feasibility and cost-effectiveness of preserving these buildings for at least 15 years or more through repairs and structural strengthening works.
 
     In addition to the above inspection and survey works, the HD actively explores the application of innovative technologies to shorten inspection time and enhance effectiveness. The HD currently uses handheld infrared thermographic cameras during inspections and, when necessary, deploys small drones equipped with imaging and infrared thermographic capabilities to examine building exteriors. These drones integrate with an artificial intelligence analysis platform to automatically identify external wall defects, such as spalling of mosaic tiles, and generate risk assessment reports to prioritise items requiring attention. This approach significantly enhances the efficiency of preventive maintenance with notable overall results. Furthermore, the HD carries out comprehensive external wall inspections and repairs approximately every ten years prior to its building redecorating works.
 
(5) The HA has consistently established a set of appropriate construction standards and specifications for new public housing developments. These standards and specifications are regularly updated in response to advancement of new construction technologies, building materials, and latest codes of practice. Buildings constructed in Hong Kong during the 1970s and 1980s, including public housing estates developed by the HA at that time, were commonly constructed with mosaic tiles as finishing material. Since around 2010, the HA has adopted a cleaner design for public housing. Consequently, the external walls, corridors and lift lobby walls of residential blocks in public housing estates are mainly finished with paint, while ceramic tiles are incorporated into the lobby design. Given the diverse colours of mosaic tiles and their applicability to different patterns, mosaic tiles continue to be used occasionally for feature walls in public spaces of housing projects as a highlight.

Ends/Wednesday, October 8, 2025
Issued at HKT 13:20

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