Hong Kong Regulations

BUILDING (STANDARDS OF SANITARY FITMENTS, PLUMBING, DRAINAGE WORKS AND LATRINES) REGULATIONS - REGULATION 37

Pipes in ducts

Where a soil pipe, waste pipe, anti-syphonage pipe, ventilating pipe, or
rain water pipe is fixed in a duct within a building, access panels shall be
provided of such size and so situated that adequate access is available to all
pipe connexions within the duct.