Can You Get Retrospective Approval for a Shed in WA?
Usually yes. A registered building surveyor inspects the shed and, if it complies, issues a certificate of building compliance called a BA18. You then apply to your council for a building approval certificate, a BA13. Where planning approval is also needed it must be obtained first. Most sheds that were built sensibly get through.
An unapproved shed is a paperwork problem, not usually a demolition problem.
The City of Melville states it on its own website. In most cases, where the work complies with the performance requirements of the Building Code and the relevant Australian Standards, the council grants retrospective approval. Where it does not, the council works with the owner to identify what would make it compliant. Removal is the last option, not the first.
Councils are not looking for reasons to knock down your shed. They are looking for a compliant building on their records.
A shed also has one advantage over almost every other structure people need to fix: it can often be moved. Where a patio or an extension has to be modified or argued, a shed can sometimes be relocated a metre and the problem disappears.
How People Find Out Their Shed Was Never Approved
Selling the house
The most common by a distance. The buyer’s settlement agent asks the council for the approvals on the property, there is nothing on file for the shed, and now there is a compliance issue in the middle of a settlement with a date on it.
An insurance claim
A storm takes the shed, or the shed damages something else. You claim, the insurer asks for the building approval.
A letter from council
Sometimes prompted by a neighbour, sometimes by aerial imagery during a routine review. Usually a request for information rather than an order.
You bought it that way
Very common. The previous owner built it and it is now your shed and your compliance issue. Melville’s guidance covers exactly this case, for people who purchased a property with unauthorised building work.
How Retrospective Shed Approval Works
Four steps. It runs differently to a normal approval because the building already exists, so nobody is assessing a proposal. They are assessing a structure.
Step 1: measure and draw what is actually there
Not what was intended. What was built.
We measure the shed on site: dimensions, wall and ridge heights from natural ground level, setbacks to each boundary, distance to the house, floor level, and how it is fixed down. Then we draw it exactly as it stands, to the same standard a new application would need. See shed plans.
This step finds the surprises. Sheds get placed by eye and drift. A slab poured 300mm out, a shed erected closer to the fence than the invoice said, an extension added later that nobody drew.
Where the shed sits close to a boundary, a Regulation 25a survey certificate may be required depending on its proximity to the lot boundary or another structure. That is a licensed surveyor confirming exactly where the structure sits, and on a boundary shed it is often the difference between an approval and an argument.
Step 2: check it against the rules
Two sets, and both have to be satisfied.
Planning. The R-Codes and your council’s policy: total outbuilding area against the 60m² or 10 per cent cap, wall and ridge height, setbacks, whether it sits in the street setback area, and whether enough open space and outdoor living area is left. Which numbers apply depends on whether your lot is Part B or Part C, and that is set by your density code. See council approval for a shed.
Building. The National Construction Code: structural adequacy, footings and tie-down, and fire separation from the boundary and from the house. See sheds on the boundary.
Where the shed misses a deemed-to-comply planning standard, the design principles pathway is available exactly as it would be for a new application. For outbuildings the principle is that they should not detract from the streetscape or the visual amenity of residents or neighbouring properties, which tells you what to argue. See justification letters
Step 3: the building surveyor inspection and the BA18
The part that does not exist in a normal application.
An independent registered building surveyor inspects the shed and, if satisfied, issues a certificate of building compliance, a BA18, confirming the structure as built complies with the applicable standards.
The surveyor will usually also want a certificate from a practising structural engineer confirming structural adequacy and compliance with the Building Code’s structural provisions. On a shed that means somebody checking the footings and the tie-down on a structure that is already up.
Be ready for the surveyor to ask for something to be exposed. Footings are the usual one, and on a shed they are frequently the whole question, because a shed that was never engineered often has no footings worth the name.
Step 4: lodge the BA13
With the BA18 in hand you apply to the council for a building approval certificate, a BA13, which is the retrospective equivalent of a building permit for a Class 10 structure.
Order matters. If planning approval is also required, it has to be obtained before you can apply for the building approval certificate.
The application goes in with the BA18, copies of all the plans and specifications the BA18 refers to, evidence of any planning approval, the structural engineer’s certificate, a Regulation 25a survey certificate where required, and the fees and levies. If the shed encroaches on or affects neighbouring land, you also need evidence of consent from that owner.
We prepare it, lodge it and answer whatever comes back.
What If the Shed Does Not Comply?
Four routes, in the order worth trying them.
Modify it
Often smaller than people fear. Adding a compliant footing detail, replacing a wall sheet with a fire-rated one, trimming an eave, adding tie-down.
A physical fix beats a written argument, because a compliant structure cannot be knocked back on judgement.
Move it
The option a shed has and most structures do not.
If the shed is 400mm too close to the boundary, and the fire separation cannot be achieved to the house either, sometimes the cheapest answer is to shift the shed. On a bolted-down kit shed on a modest slab that can be a day’s work.
Always price this against the cost of arguing it. Clients are often surprised which way it lands.
Argue it
Where the shed misses a planning standard rather than a building one, the design principles pathway lets you justify the departure instead of meeting the number.
It works when there is a real argument: the shed is invisible from the street, it is screened, the neighbour has one the same, the lot is an odd shape. It does not work when the answer is simply that the rule was not followed.
Remove it
The last resort, and genuinely rare for a shed, precisely because moving it is usually available first.
If a council does move to enforcement there is time in the process: Melville’s published process gives 14 days’ notice of intent to issue a building order and 28 days to comply once issued, with a right of review to the State Administrative Tribunal within 28 days.
The Shed-Specific Problems We See
Three that come up on sheds and almost nothing else.
It is over the 10 per cent site area limit
The single most common planning failure on a retrospective shed.
Under Part B your total outbuilding area is capped at 60m² or 10 per cent of the site, whichever is less. On a 400m² lot that is 40m². On a 300m² lot it is 30m². People buy a shed sized to the yard, not to the rule.
If your lot is R50 or above, check before you panic. Part C has no 10 per cent rule at all, so the cap is a flat 60m², and the wall height allowance is more generous too. The same shed can be compliant or not depending purely on the density code.
It is in the street setback area
No shed is permitted in the primary or secondary street setback area, and corner lots have two.
This is the hardest one to argue and the easiest one to fix by moving it.
Someone has been living in it
Say so early. It changes the job completely.
A shed is a Class 10 non-habitable structure. If it has been fitted out and occupied, you are no longer looking at retrospective approval of a shed. You are looking at a change of building classification to Class 1a, with everything that brings: damp proofing, ceiling heights, light and ventilation, insulation, smoke alarms and termite protection. That is covered on converting a shed to a granny flat.
We would much rather hear it on the first call than find a kitchen during the measure-up.
How Much Does Retrospective Shed Approval Cost?
More than doing it properly the first time, and deliberately so. Expect drafting from around $750 + GST, a building surveyor’s fee higher than a standard certificate because it includes a site inspection, a structural engineer’s certificate, and council fees that carry a penalty loading. The City of Melville charges three times the standard fee for a retrospective development application.
| What | Rough guide |
| Drafting the as-built shed | from around $750 + GST |
| Independent building surveyor, BA18 | quoted per job. More than a standard certificate of design compliance because it involves a site inspection |
| Structural engineer’s certificate | quoted per job |
| Regulation 25a survey certificate, where required | varies by surveyor |
| Council planning fee | the City of Melville charges three times the standard fee for a retrospective development application, by way of penalty |
| Council building approval certificate fee | per the council’s fee schedule |
| Physically moving or modifying the shed, if needed | quoted by your builder |
That triple planning fee is a published penalty, not a negotiation, and other councils take similar approaches.
How Long It Takes
Allow about two weeks in our queue and a week to draw the as-built set. The building surveyor’s inspection is scheduled on top, and how quickly that happens depends on the surveyor and on whether footings need exposing.
Then the council. A building approval certificate runs on a similar clock to a permit, and a retrospective development application runs the same 60 day statutory period as any other.
Realistically six to twelve weeks, and longer if the shed needs moving or modifying.
If you are in a settlement, say so on the first call. It changes how we sequence the job and it is the most useful thing you can tell us.
Retrospective Shed Approval FAQs
Can I get retrospective approval for a shed in WA?
Usually yes. Where the structure complies with the performance requirements of the Building Code and the relevant Australian Standards, councils generally grant retrospective approval. The route is a certificate of building compliance, a BA18, from a registered building surveyor, then a building approval certificate, a BA13, from your council.
Will I be fined for building a shed without approval?
Building work without a permit is an offence under section 9 of the Building Act 2011, so the possibility exists. In practice councils focus on getting the structure compliant and on their records. The cost most people meet is a penalty fee on the retrospective application rather than a prosecution.
What is a BA18 and why do I need one?
A certificate of building compliance, signed by an independent registered building surveyor, confirming the structure as built complies with the applicable standards. Without one you cannot apply for a building approval certificate.
I bought a house with an unapproved shed. Is it my problem?
Yes. It transfers with the property. The upside is that it is fixable, and far better dealt with while you own the house than while you are trying to sell it.
What if the shed is too close to the boundary?
Not automatically fatal. Sometimes the fix is achieving the 900mm fire separation to the house rather than the boundary. Sometimes it is a written justification. Sometimes it is moving the shed a metre, which for a shed is often the cheapest answer of the three.
My shed is bigger than the rules allow. Now what?
Check which R-Codes Part applies to your lot first, because the caps differ significantly. After that it is a design principles argument, a modification, or removal of part of the structure. Being over on area is harder to argue than being over on height, because area is not something screening or position can mitigate.
Can You Leave an Unapproved Shed As-Is?
You can, and plenty of people do until they sell. The two things that force the issue are a sale and an insurance claim, and neither happens at a time you get to choose. More on that on building a shed without council approval [link to: /shed-without-council-approval].
Send Us a Photo and We Will Tell You Straight
You do not need to have worked anything out before you call. Send a photo of the shed, your address, and roughly when it went up. We will come back within 24 hours with what is involved, what it will cost, and whether we think it is straightforward.
General guidance only, current at July 2026. Retrospective approval processes and fees vary by council, and compliance is assessed by a registered building surveyor against your specific structure. This is not legal advice.
