(1) If a building permit is issued, the building work—
(a) must commence—
(i) in the case of the re-erection of a Class 1 or 10 building within 6 months of the date of issue of the building permit; and
(ii) in any other case within 12 months of the date of issue of the building permit; and
(b) must be completed—
(i) within 6 months after the building work commences in the case of a swimming pool or spa, or any barrier or safety equipment associated with a swimming pool or spa; or
(ii) within 24 months of the date of issue of the building permit in the case of any other Class 1 or 10 building; or
(iii) within 12 months of the date of issue of the building permit in the case of a permit to re-erect a building; or
(iv) within 36 months of the date of issue of the building permit in any other case.
(2) If a building permit is issued for a stage of building work a reference in sub-regulation (1)(b) to the issue of a permit is deemed to be a reference to the issue of the building permit for the first stage of the building work.
(3) A building permit lapses if the building work authorised by that permit has not commenced or is not completed within the periods specified in sub-regulation (1).
(4) The relevant building surveyor may extend the period within which any building work is required to be commenced or completed under sub-regulation (1) prior to the lapse of the permit if the relevant building surveyor considers that the extent of the building work warrants an extension.