Save as otherwise provided in this Act or any bye-law made thereunder, no land or building shall be entered without the consent of the occupier, or if there is no occupier, of the owner thereof and no such entry shall be made without giving the said owner or occupier, as the case may be, not less than twenty-four hours written notice of the intention to make such entry:
Provided that no such notice shall be necessary if the place to be inspected is a factory or workshop or trade premises or a place used for any of the purposes specified in section 417 or a stable for horses or a shed for cattle or a latrine or urinal or a work under construction, or for the purpose of ascertaining whether any animal intended for human food is slaughtered in that place in contravention of this Act or any bye-law made thereunder.