PERTHBuilding permits in WA: BA1, BA2, and when you need one
WA building permits: the certified (BA1) and uncertified (BA2) routes, the 10 vs 25 business-day timeframes, Schedule 4 exemptions
Before almost any building work starts in Western Australia, you need a building permit, and it is an offence under the Building Act 2011 to build without one. But the permit comes in two forms, on very different timelines, and knowing which you need saves weeks. Here is how the WA system works, and what a buyer should check on a home that has been altered.
Why permits exist
A building permit is how proposed work gets checked against the Building Code of Australia before it is built. It is not the same as planning or town planning approval, which deals with land use and the look of a development. The building permit is about whether the structure itself will be safe, healthy and compliant. Both can be required on the one project, and they are separate processes.
Permit authorities — usually your local government — issue permits and enforce the requirements, operating under the Building Act 2011 and Building Regulations 2012.
The two permit types
There are two application routes, and the difference is who checks the plans.
A certified application (BA1) comes with a Certificate of Design Compliance already completed by a registered building surveyor, who has checked the design against the BCA before it reaches the council. Because the compliance check is done, the council's job is administrative, and it has a short statutory window — commonly around 10 business days — to process it. Certified applications are mandatory for commercial buildings (Class 2 to 9) and optional for houses.
An uncertified application (BA2) can only be used for residential Class 1a and Class 10 buildings, and it goes to the council without that certificate, so the council does the compliance assessment itself. That takes longer — commonly around 25 business days. If the council needs more information it can request it, and you generally have 21 days to supply it, after which the council can refuse the application and keep the fee.
When you do not need one
Schedule 4 of the Building Regulations lists work that does not require a building permit — typically minor repair and maintenance. The catch worth understanding is that the exemption is only from the permit, not from the standards: the owner still has to ensure exempt work complies with the applicable building standards. Skipping the permit does not mean skipping the rules.
What this means when you are buying
Here is where it matters to a buyer. If a home has been extended, had a patio or carport added, a wall removed, or a bathroom relocated, that work should have had a permit where one was required. Unpermitted building work is a real problem to inherit: it can mean the work was never checked for compliance, and resolving it after the fact can require a building approval certificate for the unauthorised work.
So on a home that shows signs of alteration, the questions are worth asking: was a permit obtained, and does the finished work match what was approved? A pre-purchase inspection reports the physical condition and flags work that looks like it was done outside a permit — an addition built differently from the original, or structural changes with no sign of proper approval. Confirming the permit history itself is a question for the local government's records, and it is worth asking before you are committed.
Where the concern is that a builder did not build to the approved plans, that is its own issue, covered in our guide on building to approved plans.
What a permit is really protecting
A building permit can feel like an obstacle between an owner and the work they want done, but it is worth understanding what the permit system is actually protecting, because it changes how you read its absence. A permit means that the proposed work has been assessed against the building standards before it is built, that it is being carried out by someone appropriately registered where that is required, and that there is an official record of the work attached to the property. The permit is not primarily about revenue or bureaucracy; it is the mechanism by which the community, and every future owner of the property, gets some assurance that significant building work was designed and built to standard rather than improvised.
The consequence of this is that unpermitted work, work that required a permit and did not get one, is a genuine problem rather than a technicality, because it means significant work was done without that assessment and without that record. It might be perfectly sound, but nobody checked, and there is no official confirmation that it meets the standards. When such work later comes to light, on sale, on a subsequent renovation, or when its non-compliance causes a problem, regularising it can be required, and that can mean assessment, modification, or in some cases removal, at the owner's cost. The permit felt like an obstacle. It was protection the work never received.
Where the line falls between permit and no permit
Not all building work requires a permit, and knowing roughly where the line falls helps an owner understand their obligations and a buyer read a property's history. Significant structural work, work that affects the structure of a building, and building work above certain thresholds require a permit, because that is the work whose failure has the most serious consequences and that most needs assessment. At the other end, genuinely minor work, ordinary maintenance, repair, and small non-structural jobs, generally does not require a permit, because the risk it carries is low and requiring assessment would be disproportionate.
The difficulty is in the middle, and it is where owners and previous owners most often get it wrong, usually by assuming a job is minor enough not to need a permit when it actually crosses the line. A patio or carport, a structural alteration that looked cosmetic, a wall removed, an addition that seemed small, these are the jobs where the assumption that no permit was needed turns out to be wrong. When in doubt, ask. The safe course for an owner contemplating work is to confirm whether a permit is required rather than assuming, because the cost of the permit is small against the cost of regularising unpermitted work later.
What it means when you are buying
For a buyer, the permit history of a property is part of the picture of what you are taking on, because unpermitted work becomes the new owner's liability. Where a property has visible additions or alterations, a patio, an extension, a converted garage, a removed wall, a second bathroom, it is worth establishing through your settlement agent whether that work was permitted, because a gap between what is physically there and what appears in the property's records is a sign of possible unpermitted work. This is not about finding a reason to walk away; additions are made to houses all the time and most are fine. It is about knowing, before you commit, whether the house carries work that might have to be regularised at your expense.
An inspection assesses the physical condition of what is there, including additions and alterations, and can note where work appears to have been done, but it does not certify whether that work was permitted, which is a records question rather than a condition one. The two together, the inspection telling you the state of the work and the records telling you whether it was approved, give a buyer the full picture: not just whether the addition is sound, but whether it exists properly in the eyes of the system, or whether it is a liability waiting to surface. On an established home with a history of alterations, both questions are worth answering before settlement rather than after.
Common questions
Do I need a building permit in WA?
For almost all building work, yes — it is an offence under the Building Act 2011 to build without one. Schedule 4 of the Building Regulations lists exempt work, typically minor repair and maintenance, but exempt work still has to comply with the building standards.
What is the difference between a certified and uncertified permit?
A certified application (BA1) comes with a Certificate of Design Compliance from a registered building surveyor and is processed faster, commonly around 10 business days. An uncertified application (BA2), for residential Class 1a and 10 only, is assessed by the council itself and takes longer, commonly around 25 business days.
Is a building permit the same as planning approval?
No. Planning approval deals with land use and development; a building permit checks the structure against the Building Code of Australia. Both can be required, as separate processes.
This comes up on every pre-purchase building inspection and building investigation & diagnostics we carry out.
Read next: your builder has to build the house that was approved and notice of Completion: the BA7 that closes out a build.
Sources
Read rather than recalled. Summarised here; the documents themselves are Crown copyright and are linked rather than reproduced.