Section 32 provides for building control approval to lapse automatically if the works have not sufficiently commenced within three years of the day the application was made. 

Sufficiently commenced can mean different stages for different buildings, for complex buildings (i.e. buildings constructed on a shared foundation/plinth or public buildings)  commencement is when the foundations supporting the building and structure of the lowest floor of that building are complete. 

For non-complex or horizontal extensions of buildings works are commenced once the sub-surface structure including all foundations and the structure of the ground floor is complete. 

Where the building work consist of any other work commencement is when 15% of the proposed works have been completed.