Written answer by Ministry of National Development on assessing risks of sinkhole formation

Sep 25, 2025

Question No: 270

Question by: Ms He Ting Ru

To ask the Minister for National Development (a) what measures were previously put in place to prevent and assess the risks to the formation of sinkholes; (b) whether the BCA conducts regular tests of the subterranean integrity of underground structures; and (c) whether these will be updated in the light of the July 2025 sinkhole incident.

Answer:

The Building and Construction Authority (BCA) has a rigorous regulatory regime for underground works. Project owners, along with their appointed contractors and consultants, are responsible for complying with these regulations. This includes monitoring ground and building movements during the construction process for all large-scale underground tunnelling or excavation works. If there are contraventions to the Building Control Act, BCA will investigate and take errant parties to task. 

The investigations into the July 2025 sinkhole incident are still ongoing. BCA will review its measures to assess if changes are required after the investigations have concluded.