The usual sequence

Commencement, excavation, foundations (before pour), oversite, damp-proof course, drainage, structural completion, insulation before plasterboard, and final inspection.

When stages are combined

On small projects, several stages may happen in one visit. On larger work each stage is separate. Either way, the builder is responsible for calling the inspector at the right moment.

What happens at each

The inspector checks the work specific to that stage, makes notes, and either signs it off or issues a list of items to address before moving on.