Information Paper for the Provisional Legislative Council
Panel on Housing
Construction quality and structural safety of buildings under subsidised home ownership schemes
and the responsibility of the Housing Authority
This paper informs Members of the measures taken by the Housing Department (HD) to ensure the construction quality and structural safety of buildings under subsidised home ownership schemes and the latest development of soil settlement problems in On Ning Garden and Kam Fung Court.
2. Subsidised home ownership is encouraged through, inter alia, subsidised Home Ownership Scheme (HOS) and the Private Sector Participation Scheme (PSPS). The HOS is undertaken by the Housing Authority (HA), while the PSPS is undertaken by private developers in accordance with Conditions of Sale set out by the Government.
Home Ownership Scheme
3. HD is responsible for the construction of HOS projects. To ensure that the required standard of quality is achieved, HD takes various measures in managing the contractors and material suppliers.
Listing of Approved Contractors
4. Only contractors on HA's list of approved building contractors are allowed to tender for building works of the HA. Past track record of contractors' work and performance is a major factor in considering contractors' capability for inclusion on the list. They are also required to register under the International Standards Organisation (ISO). Their status on the list is regularly reviewed by HD and their tendering opportunities are allocated strictly on a performance basis.
Standardisation of Building Components
5. To further improve the quality of construction, recent standard HOS designs place emphasis on standardisation of building components and the use of factory production techniques rather than labour intensive works on site. This helps minimise human errors.
Listing of Approved Suppliers and Materials
6. HD maintains lists of approved suppliers for factory produced building components. Production standards are checked through regular factory inspections and random testing of products both at factory and on site to ensure compliance with specifications. These suppliers are also required to be registered under the ISO.
7. Besides, HD maintains lists of approved building materials. The suppliers of these products must carry out testing to ensure compliance with specifications. Factory inspections are conducted too.
Performance Assessment Scoring System (PASS)
8. Using an objective scoring system, HD's staff assess contractors' performance in terms of workmanship and safety on a monthly basis. In managing the HA's List of approved contractors, the principle is that contractors with better track record will have more tendering opportunities. PASS is an incentive for contractors to improve their workmanship as their tendering opportunities for the works contracts are dependent upon the PASS scores.
9. The construction works are closely supervised by qualified site staff to ensure that the works are completed in accordance with the specifications in materials and workmanship. Any defects identified are made good before the construction works are completed.
10. The building contractor is liable to remedy any building defects for one year after completion of the construction works. When this one year liability period expires, the owners will take up the maintenance responsibility. The contractors are responsible for latent defects resulting from defective materials or workmanship but can only be detected at a later stage.
Private Sector Participation Scheme
11. Under PSPS, private developers instead of HA are the developers of the housing projects. The developers are required to comply with the Conditions of Sale which set out all the requirements for the project. A Technical Schedule, which is included in the Conditions of Sale, stipulates all the specifications and standards for construction works, fittings and finishes for the residential flats. The Technical Schedule is under review from time to time to keep it in line with the latest specifications and standards for HOS projects as far as practicable.
12. As with other private sector developments, the developer under PSPS has to employ an Authorised Person (AP) to hold responsibility for the project design, submission of building plans in accordance with the Buildings Ordinance, supervision of construction and development progress, and to ensure that the completed development complies with the Conditions of Sale including the Technical Schedule. In addition, HD appoints an independent surveyor to monitor progress and generally oversee the development of a project.
13. Since 1993, Government has introduced further measures to enhance the quality of PSPS flats so as to cope with rising expectations of the community. These measures include upgrading of finishing requirements, more stringent control on selection of contractors and extension of liability period for scheduled defects. We will continue to look at ways to improve the existing mechanism for monitoring the work of developers under the PSPS.
14. The building structures and foundations are designed and checked by qualified professionals to ensure that they comply with the Buildings ( Construction) Regulations and relevant codes of practices. In principle, the foundations are designed to found on firm stratum and buildings are designed to sustain the worst wind and gravity loads combination.
15. The construction works are carried out by registered contractors and supervised by qualified site staff to ensure that the buildings are constructed as designed and specified, and they are structurally safe for their intended use.
Kam Fung Court
16. Kam Fung Court is a HOS project comprising nine residential blocks situated on newly reclaimed land in Ma On Shan. Although reclaimed land is subject to settlement, this is allowed for in the design and construction of the estate. The buildings were constructed on piled foundations resting on firm stratum and, therefore, they should not be affected by any subsequent soil settlement. HD has been monitoring the structural safety and levels of the buildings to ensure that they have not been affected by soil settlement since the completion of their construction. The results show that the buildings have not been affected by the soil settlement and they are structurally safe.
17. During construction, measures were taken to accelerate soil settlement in order to minimise any subsequent settlement and damage to the external areas after completion of construction. External areas and services were specifically designed to accommodate such subsequent settlement. The Housing Authority will take up the necessary investigation and repairs associated with soil settlement on this reclaimed site.
On Ning Garden
18. The latest development on the rectification of defects caused by soil settlement is summarised in the information paper attached at Annex.