4.—(1) A person on whom a completion notice is served may, not later than twenty-eight days from the date of service on him of the notice, appeal to the Commissioner against the notice on the ground that the building to which the notice relates has not been or, as the case may be, cannot reasonably be expected to be completed by the day stated in the notice.N.I.
(2) Where a person appeals against a completion notice and the appeal is not abandoned or dismissed, the completion day shall be such day as the Commissioner shall determine.]