87.—(1) A person on whom a notice has been served under Article 79, 80 or 81, or paragraph 2 of Schedule 4 (notices requiring the execution of works) who wilfully fails to comply with the notice shall be guilty of an offence and liable on summary conviction to a fine not exceeding level 4 on the standard scale.
(2) The obligation to execute the works specified in the notice continues notwithstanding that the period for compliance has expired; and a person who wilfully fails to comply with that obligation, after being convicted of an offence in relation to the notice under paragraph (1) or this paragraph, shall be guilty of a further offence and liable on summary conviction to a fine not exceeding level 4 on the standard scale.
(3) In this Article compliance with a notice means the completion of the works specified in the notice within the period of compliance, which is—
(a)if no appeal is brought against the notice, the period specified in the notice with any extension duly allowed by the Executive;
(b)if an appeal is brought against the notice, and the notice is confirmed in whole or in part on the appeal, the period of 28 days from the final determination of the appeal or such longer period as the court in determining the appeal may fix.
(4) No liability arises under paragraph (1) if the Executive, on being notified in accordance with Article 84(6) that the person on whom the notice was served is not able to do the work in question, serves notice that it proposes to do the work and relieves him from liability under paragraph (1).
(5) The provisons of this Article are without prejudice to the exercise by the Executive of its power under Article 84 to carry out the works itself.