The certificate of design compliance is the primary check that the proposed building or incidental structure, if completed in accordance with the plans and specifications lodged with the building permit application, will comply with the building standards. This is only used for proposed new construction in support of a building permit application. Once work has commenced or been completed it cannot be used as it is linked to a specific building permit and in turn is referenced by the certificate of construction compliance.

A certificate of construction compliance once issued confirms that the building assessed by a building surveyor at design stage and given a certificate of design compliance has been constructed in accordance with that certificate and the building permit. It cannot be used or issued where work presented is not subject to a building permit or certificate of design compliance. (Unauthorised work)

A certificate of building compliance confirms that an existing building complies with the relevant building standards.

For an existing building whose construction was authorised under the laws of the time, the building standards will be those that applied at the time of construction. The building surveyor in giving the certificate of building compliance is confirming that there have been no obvious departures from the original building permit and that the building is safe to occupy. The certificate of building compliance is used to support a change of use and building classification and to support an application for a building approval certificate where buildings are constructed without a building permit.