BA18 Retrospective Approval (WA)
Council says your patio/shed or new build wasn’t approved? We prepare BA18 retrospective applications in WA.
Get the right documents assembled and packaged so you can respond to council requirements and move toward formal approval.
Call now for a free 10-minute BA18 suitability check.
WA-focused approvals service (patios, sheds, outbuildings)
Clear scope before you pay
Documented process: assess → scope → quote → produce docs
We work with engineers/surveyors as required (third-party fees may apply)
Transparent timelines: depends on site info + third parties + council
Price: “BA18 varies depending on what exists on site and what council requests. We confirm scope first, then quote.”
Time: “Fastest path is providing complete photos + measurements upfront. Missing info is the main cause of delays.”
Council delays: “We can’t control council timeframes. We reduce risk of further requests by submitting complete, consistent documents.”
Get a BA18 Quote
Upload or email through any council letter, photos, and (if available) existing plans. To info@patioandshedapprovals.com.au
We’ll confirm scope and next steps.
We specialise exclusively in retrospective approvals, prepare documentation remotely using advanced site data, and liaise directly with engineers and building surveyors—saving you time, avoiding resubmissions, and reducing council back-and-forth.
We prepare BA18 retrospective building approval packages for structures already built without a permit, tailored precisely to council and NCC 2022 requirements. For non-habitable Class 10a structures—including patios, sheds, carports, decks, pools and spas—we prepare a compliant site plan, elevations, and structural engineering specifications, all reviewed and signed off by a registered building surveyor as a BA18 Certificate of Building Compliance. For habitable Class 1a structures, such as granny flats, extensions and renovations, we prepare a full retrospective compliance package including site plans, elevations, engineering, NCC-compliant energy efficiency documentation, and building surveyor certification under a BA18. All applications are completed with the required council application forms and prepared specifically to meet local government, NCC 2022 and WA Building Act standards, maximising approval success and minimising further council delays
BA18 for Class 10a Structures (Non-Habitable)
Patios, sheds, carports, decks, pools and spas are classified as Class 10a structures and still require retrospective approval if built without a permit. We prepare:
Council-compliant site plan
Accurate as-constructed elevations
Structural engineering specifications
BA18 Certificate of Building Compliance issued by a registered building surveyor
This package is designed to clearly demonstrate structural adequacy and compliance, reducing the risk of demolition orders or enforcement action.
BA18 for Class 1a Structures (Habitable)
Habitable structures such as granny flats, extensions and renovations require a higher level of compliance due to occupancy and safety requirements. Our BA18 packages include:
Site plan and detailed elevations
Structural engineering
Energy efficiency documentation compliant with NCC 2022
Building surveyor sign-off under a BA18
This ensures the dwelling meets minimum health, safety and performance standards required for retrospective approval.
Received a council notice, compliance letter or enforcement warning? A BA18 retrospective approval is often the only way to legalise unapproved building works without removal. We prepare council-ready BA18 approval packages for both Class 10a structures (patios, sheds, carports, decks, pools and spas) and Class 1a dwellings (granny flats, extensions and renovations), including all plans, engineering, energy efficiency (where required) and registered building surveyor certification. Our documentation is prepared specifically to meet WA council requirements, giving you the fastest and most reliable pathway to retrospective approval.