Where any works have been carried out in contravention of the provisions of subsection (1) of section thirty-three of this Act, the local planning authority may serve on the owner and occupier of the building in question a notice under this section requiring such steps for restoring the building to its former state as may be specified in the notice to be taken within such period as may be so specified.

Subject to the next following section, a notice under this section shall take effect at the end of such period (not being less than twenty-eight days after the service thereof) as may be specified in the notice.

Without prejudice to the preceding provisions of this section, if any person contravenes the provisions of subsection (1) of section thirty-three of this Act, he shall be guilty of an offence, and shall be liable on summary conviction to a fine not exceeding one hundred pounds.