Building inspections by competent persons and cadets

This information relates to the inspection of stages for single, detached class 1a buildings and relevant class 10 buildings or structures.

Competent persons

A building certifier may use a competent person to provide inspection help for aspects of a stage of building work. The building certifier must first determine that the person is competent to provide the inspection help.

Read Part 6 of the Building Regulation 2021 for the requirements for competency.


A cadet is a person appointed to help a building certifier perform building certifying functions.

They are usually:

  • employed by a local government or private certifier
  • completing studies to become licensed as a building certifier.

Cadets are not licensed and can only help building certifiers assess and inspect building work under supervision.

If a cadet is employed by a local government or private certifier, they can't be used as a competent person by these employers.

However, a building certifier from one organisation may use a cadet from another organisation if the cadet meets the regulation requirements.

Inspections for single detached Class 1a buildings and relevant class 10 buildings or structures

Excavation, footings and/or slab stage

A building certifier can rely on a suitably qualified competent person to help inspect aspects of the excavation, footings and/or slab stages for single detached class 1a buildings and relevant class 10 buildings or structures.

However, a competent person providing an aspect inspection certificate for the boundary clearance aspect of a single detached class 1a building must be a cadastral surveyor. Additionally, a building certifier must not decide an individual is a competent person to give inspection help for the following work unless the individual is a registered professional engineer:

  • reinforcement of footing system work for a single detached class 1a building
  • formwork and reinforcement for a slab for a single detached class 1a building.

The building certifier must sign the inspection certificate for the excavation footings and/or slab stage, even if they rely on competent persons for all aspects.

Final stage

For both a class 1a building or a class 10 building or structure, a building certifier must personally inspect the final stage of inspection. A competent person can inspect some, but not all, aspects of the final stage.


The competent person must give the building certifier a Form 12 – Aspect Inspection Certificate (Appointed Competent Person) (PDF, 150KB) for work they complete so the building certifier can confirm a stage is complete.

To certify a stage, a building certifier needs certificates for all the relevant aspects that make up the stage.

Swimming Pools

The requirements for the inspection of swimming pools are outlined in section 44(1)(e) of the Building Regulation 2021 and the QDC MP 3.4. Only a building certifier may sign the relevant stages of inspection for swimming pools as per the requirements under the QDC MP 3.4.