No. For structural works that are exempted from URA's written permission pertaining to site preparation works, they can be submitted via the "Piling Gateway" application form right after the Design Gateway submission has been made (note: DG does not need to be approved yet)
At Construction Gateway submission, the structural works should comprise the main structure. For projects eligible for part ST submission, the "Structural works" section in CG should contain the 1st part ST along with the carcass of the entire development. The following part STs can be applied through
Independent submission > BCA > Structural works and permit application
For more details, please refer to our link https://info.corenet.gov.sg/regulatory-process/other-building-works/part-st-submissions