69.—Where a person on whom a planning authority has served a notice under section 59(1) or 60(2) fails to comply with the notice, the planning authority may take such steps as it considers reasonable and necessary to give effect to the terms of the notice including—

(a) entry on land by authorised persons in accordance with section 252, and

(b) the carrying out, or arranging the carrying out, of the works specified in the notice.