If a notice under section fourteen, section fifteen or section sixteen of this Act is not complied with, then, after the expiration of the time within which the works are required to be executed or, if an appeal has been made against the notice and upon that appeal the notice has been confirmed with or without variation, after the expiration of twenty-one days from the final determination of the appeal, or such longer period as the court in determining the appeal may fix, the local authority may themselves do the work required to be done by the notice (with any variation made by the court).
Notwithstanding the foregoing subsection, if before the expiration of the time mentioned in that subsection the person on whom the notice was served notifies the local authority in writing that he does not intend to do the work in question, the local authority may, if they think fit, themselves do the work forthwith.
If a local authority applies to a county court and satisfies the court—
the court, if satisfied that that person has had proper notice of the application, may order him to make such payment or payments to the local authority as may appear to the court to be just.
In all summary proceedings by the local authority for the recovery of expenses under this section, the time within which the proceedings may be taken shall be reckoned from the date of the service of the demand.
Any interest payable under this section shall be at the rate, or the highest rate, for the time being fixed under subsection (6) of section ten of the principal Act.
In proceedings by the local authority for the recovery of any expenses under subsection (3) of this section it shall not be open to the defendant to raise any question which he could have raised on an appeal under the foregoing provisions of this Part of this Act against the notice requiring the execution of the works.