Retrospective approvals for unauthorised building works - structural engineer certification

An unauthorised structure is a building or structure that has been constructed without a Building Permit from the relevant permit authority (i.e. local government). In most cases you may be able to submit a retrospective approval to the local government authority. If the building or structure was constructed in accordance with certified structural engineer's drawings, the retrospective approval is generally easier to obtain. Our structural engineering team and our building surveyor can provide all the documents you require to obtain your Council approval for your unauthorised building works in Perth.

We have assisted several Clients in recent weeks with retrospective engineering approvals for non-habitable structures. If constructed well, Class 10a buildings such as sheds, carports, patios and private garages or Class 10b structures such as fences, retaining walls, swimming pools or the like, are likely to be able to be certified retrospectively.

In most cases, it is advised that a structural inspection is undertaken to assess the structure and to confirm if it can be certified from an engineering perspective (certification for compliance with the current version of the National Construction Code). This enables us to provide a document with advice regarding the current structural condition and recommendation for additional structural design work to achieve structural adequacy, if required.

In almost all cases, we need to undertake structural analysis, calculations, mark-up specification before providing our Chartered Engineer Certification for the structure.

Usually, your local Council will require an independent Building Surveyor Inspection, which we can coordinate, to obtain the BA18 Certificate of Building Compliance. Following our certification and the BA18, retrospective approval in Western Australia can usually be obtained within 10 business days.

In Perth, Western Australia, The Department of Mines, Industry Regulation and Safety (formerly the Department of Commerce) provides a good general overview on unauthorised building work and building approvals for Class 1 to Class 10 buildings.

The retrospective approval process is not a mechanism to circumvent the need for a building permit. However the Building Act allows a person to make an application to the relevant permit authority to approve unauthorised building work in relation to a building and/or incidental structure.

If you have undertaken building work without prior approval, or purchased a property with unauthorised structure/s it is recommend to discuss the retrospective approval process with your local Council or Shire.

For Class 1 and Class 10 structures, the typical process to obtain retrospective approval for an unauthorised building or structure involves the following steps:

Step 1 - Contact the local government authority (council or shire) and discuss the specific building or structure with a view to identify the specific process and documentation required;

Step 2 - Confirm if the unauthorised structures require planning approval. If this is the case a retrospective planning approval must be obtained from council before the Building Approval Certificate can be issued;

Step 3 - completed the Building Approval Certificate application form (such as the BA13);

Step 4 - Engage an independent Building Surveyor to confirm documentation and technical certificates that may be required such as Structural Engineer’s report, Energy efficiency report, BAL report;

Step 5 - Employ a structural engineer to undertake the necessary inspection, reporting, documentation and engineering certification in accordance with relevant standards;

Step 6 - Submit all the above documents to the relevant Council or Shire for assessment.

In most cases if the above steps are followed, a retrospective approval for unauthorised building work and/or structures can be obtained. However, if the unauthorised building / structure does not meet the performance requirements of the Building Code of Australia or relevant Australian Standards, you may be required to remove the structure.

Out team can assist with the retrospective approval process and in particular steps 4 and 5 described above. In most cases the best approach is to conduct a structural inspection on site which will enable us to provide engineering certification for the existing structure or building.

Please note that we can only assist with Council approval for your unauthorised building works and retrospective structural engineering certifications in Perth, Western Australia. Contact us to discuss your specific requirements and to obtain a quotation.

Rotaru Building Consultants

send us an email

call us: +61 432 043 518

visit our website:

3,828 views0 comments