11.—(1) Subject to paragraph (2), an authorised officer may, on production if required of his authority, enter premises at any reasonable time for the purpose of—
(a)ascertaining whether there is or has been on, or in connection with, the premises any contravention of this Order or of building regulations;
(b)applying tests for conformity with building regulations;
(c)inspecting any building, where the officer has reasonable cause for believing that a change of use of the building has taken place or is intended;
(d)exercising any functions conferred, by this Order or by building regulations, on him or the person by whom he is authorised for the purposes of this paragraph in relation to premises which fail to comply with building regulations.
(2) A person shall not enter any premises, by virtue of paragraph (1)( c), unless he has served three days' notice of his intention to do so on the occupier and (if the owner is known) also on the owner of the premises.
(3) Where a justice of the peace is satisfied by complaint in writing on oath—
(a)that there are reasonable grounds for entering into any premises for any such purpose as is mentioned in paragraph (1), and
(b)that—
(i)admission to the premises has been refused, or that a refusal is apprehended and that notice of the intention to apply for a warrant has been served on the occupier; or
(ii)an application for admission, or the serving of such notice, would defeat the object of the entry, or that the case is one of urgency, or that the premises are unoccupied or the occupier is temporarily absent,
he may, notwithstanding anything in paragraph (2), issue a warrant under his hand authorising a district council by any authorised officer, to enter the premises, by force if necessary.
(4) A person entering any premises by virtue of this Article, or of a warrant issued thereunder, may take with him such other persons as may be necessary, and on leaving any unoccupied premises which he has entered by virtue of such a warrant shall leave them as effectively secured against unauthorised entry as he found them.
(5) Every warrant granted under this Article shall continue in force for a period of twenty-eight days.
(6) Any person who wilfully obstructs any person acting in execution of any of the purposes mentioned in paragraph (1) shall be guilty of an offence under this Order.
(7) If any person who, by virtue of this Article, or of a warrant issued thereunder, enters a factory or work place, discloses to any person any information obtained by him in the factory or work place with regard to any manufacturing process or trade secret, he shall, unless the disclosure was made in the performance of his duty, be guilty of an offence under this Order.