Building work done in Western Australia without an approval it needed is “unauthorised work”, and an application can be made to the local government for a building approval certificate that approves it after the event. The City of Canning says the offence of building without approval stays with whoever did the work, not a later owner; but the Act lets a building order be directed to the owner or occupier of the land, whoever they are now.
General information, not legal advice. This page is read from the Building Act 2011, the Building Regulations 2012, Building and Energy (part of WA’s Department of Local Government, Industry Regulation and Safety) and the City of Canning. A registered building surveyor or the City’s building team can say what a particular structure needs; a lawyer can advise on a particular sale.
What counts as unauthorised
“unauthorised work means work … (a) that was done without an authority under a written law that was required by the written law applicable at the time the work was done; or (b) that did not comply with an authority under a written law that was in effect in respect of the work”
Building Act 2011 (WA), section 51(1). Based on content from the Western Australian Legislation website at 8 October 2026. For the latest information on Western Australian legislation, visit www.legislation.wa.gov.au. © State of Western Australia, CC BY 4.0
So the test is the law when the work was done, not today’s, and work can be unauthorised even with a permit if it was not built as the permit allowed. Building work without a permit, where one is required, is an offence under section 9, with fines of $50,000 for a first offence, $75,000 for a second, and $100,000 and 12 months’ imprisonment for a third or later one (as at October 2026).
What usually needs no permit
Schedule 4 of the Building Regulations lists building work that does not need a permit. A few items matter most around an established house. Most have further conditions, some including that the work is not in wind region C or D, so the regulation itself is the place to check.
| Structure | No permit needed if |
|---|---|
| Garden shed or similar | Freestanding, floor area no more than 10 m², and no more than 2.4 m high. |
| Pergola beside a house | Open, with no roof (an open-weave covering is allowed), no more than 2.4 m high and covering no more than 20 m². |
| Retaining wall | Retains no more than 0.5 m of ground and is not tied to other building work or to protecting the neighbour’s land. |
| Fence or screen | Built to the local government’s fencing local law (other than a barrier that stops people falling). |
| Repairs and renovation | No change to floor area, height, footings or structural supports, using materials commonly used for the purpose, with no change to the building’s use and no effect on its safety or its compliance with building standards. |
A roofed outdoor area is a different thing from a pergola. Building and Energy says a roofed outdoor area, commonly called a patio in WA, is a Class 10a building, the class that also takes in garages, carports and sheds, and that the permit rules for those buildings still apply.
The building approval certificate
Section 51(3) lets a person apply for a building approval certificate for a building or incidental structure on which unauthorised work has been done. The City of Canning can issue one, where the work is not under continuing enforcement action, once the owner has applied, paid the fees and shown the work meets the relevant standards and policies; the structure then joins the property’s building records.
The City’s information sheet lists what goes with the application form, the BA13: a certificate of building compliance issued by an appropriately registered building surveyor; copies of the plans and documents that certificate refers to; and any other approvals the work needs. Among the matters the local government must be satisfied of before granting the certificate are that every building order about the structure has been complied with and that the building services levy has been paid; for unauthorised work, so has any building industry training levy that would have applied.
What it costs
Two charges are set by the state: the application fee and the building services levy. For unauthorised work the fee is 0.38% of the work’s estimated value, with a minimum of $121.00. The levy is 0.274% of the value where that is over $45,000, and $123.30 at $45,000 or less. All figures are as at October 2026. For unauthorised work, the value is the work’s current value, as the permit authority determines it.
Worked example: illustrative values, not a real property
- A patio the City values at $18,000. Fee: 0.38% is $68.40, below the minimum, so $121.00. Levy: $123.30. Together, $244.30.
- A rear extension valued at $60,000. Fee: 0.38% is $228.00. Levy: 0.274% is $164.40. Together, $392.40.
Computed from Building and Energy’s fee and levy table (as at October 2026). The building surveyor’s certificate and any work needed to make the structure comply are separate costs, not set by these tables.
After the house changes hands
The City of Canning’s information sheet says the offences for unauthorised building work apply only to the person who committed them, meaning the builder or the original owner who started the work or let the building be occupied, and not to someone who later becomes the owner.
The structure itself is another matter. Under section 110, a permit authority may make a building order about a particular building or incidental structure and direct it to a person who owns or occupies the land where it stands. Such an order can require the structure to be altered, or demolished and removed, to stop a suspected breach of the Act. Section 113 holds back those kinds of order while a building approval certificate has been granted, or an application for one is waiting on a decision.
The paper trail sits with the City. Its building records, the approved plans and documents for a property, are available to the property’s owner through an archival search, which the City aims to complete within 20 working days. The Act also requires each permit authority to keep a register of permits, building approval certificates and building orders, open to public inspection in office hours, with copies on payment of any prescribed fee.
A pool or spa needs building approval too; see pool barriers and inspections, and for the switchboard, RCD safety switches when a home is sold.