17. (1) The operation of a specialised system is, on and after the commencement day, to be taken to have been declared to be a licensable public health risk activity under section 18 of the new Public Health Act.
(2) Subsection (1) does not apply to a specialised system that, immediately before the commencement day, was exempt under paragraph 42A (a) or Division 5 of Part IIIA of the unamended Building Act from the operation of that Part.
(3) On or after the commencement day, the Minister may revoke an exemption under Division 5 of Part IIIA of the unamended Building Act by written notice to the person to whom the exemption was granted if the Minister considers that such revocation is desirable in the interests of public health.