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Building safety tips

【Step-by-step guide to comply with the mandatory drainage repair order】

What exactly should you do after receiving a mandatory drainage repair order?


Hey hey hey, as Ah Build and Ah Ding always say, maintaining the drainage systems in a safe and sound condition is the key to create a safe and healthy living environment.  The Government has launched a special measure through the second round of the Anti-epidemic Fund (AEF).  Consultants engaged by the Buildings Department (BD) have proactively inspected the external drainage systems of around 20 000 private residential or composite buildings exceeding three storeys in height across the territory. If the drainage systems are found to be defective upon inspection, owners concerned will receive a mandatory drainage repair order requiring them to arrange investigations and/or repairs.  


For your safety and the safety of others, when you receive a mandatory drainage repair order for your residential unit from BD, you should comply with the order by following these guidelines:

1      Read and understand the order carefully.

2      Engage qualified professionals or registered contractors to investigate the defective drainage system.

3      Carry out necessary works, for example:

-      Repair defective drains

-      Erect an anti-syphonage pipe.  When erecting, please take environmental factors into account and erect it at the top side of the soil pipe using a proper connection fitting and place the anti-syphonage pipe as close to the trap outlet of the watercloset as possible.

-       Under the Minor Works Control System, submit Notice of Commencement and/or Certificate of Completion in accordance with the requirements of the relevant class of minor works to be carried out.

4      If necessary, owners can apply for loan or subsidy for carrying out of the repair works.

5      Inform BD officers upon completion of the required works.




To search for qualified professionals or registered contractors, please visit BD’s website for the registers:


About Minor Works Control System:


To apply for loan or subsidy to carry out repair works, please visit:


For any enquiries regarding the order, owners can contact BD officers on the telephone number on the letter, or visit BD’s website at 





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