(1) A person authorised to enter premises under this Division may enter the premises without giving notice--(a) if entry to the premises is made with the consent of the owner or occupier, or(b) if the entry is made to a part of the premises that is open to the public, or(c) if entry is required urgently and the case is one in which the Commissioner has authorised in writing (either generally or in a particular case) entry without notice.
(2) In any other case, the person must give the owner or occupier of the premises reasonable written notice of the intention to enter the premises.