A BA3 is the certificate of design compliance. It is not an application, it is a certificate signed by a registered building surveyor stating that the design of a proposed building complies with the applicable building standards. You need one to lodge a BA1 certified application for a building permit.
The BA3 is one of a series of forms approved by the Building Commissioner under the Building Act 2011 and the Building Regulations 2012. You can tell you have the current version by the “Building Commissioner Approved” line and date in the footer.
What a BA3 Actually Is
Every other form in the BA series with a low number is something you apply for. A BA3 is different. It is a certificate, and you do not fill it out.
A registered building surveyor completes and signs it, after assessing your plans against the National Construction Code and the applicable building standards. It certifies the design, not the construction.
That distinction runs through the whole form series:
| Form | Certifies | When |
| BA3 | The design complies | Before you build |
| BA17 | The construction complies with the permit | After you build |
| BA18 | An existing building complies | For unauthorised work or a change of use |
Why You Need One
A BA3 is what makes a certified application possible. Lodge a BA1 without one and it is incomplete.
If you go the uncertified route with a BA2 , you do not obtain a BA3 yourself. The council’s building surveyors assess the plans and issue the certificate as part of processing your application.
So a BA3 is not optional for the building. It is optional for you. Either you get it, or the council does.
What the Surveyor Is Certifying
That the design, as drawn, complies with the applicable building standards. In practice that means the surveyor works through the drawings against the code: structural adequacy, fire separation, damp and weatherproofing, room heights, light and ventilation, wet areas, glazing and fall protection, smoke alarms, energy, and where applicable bushfire construction.
The certificate references specific documents. Those referenced plans and specifications are what gets certified, and they have to be lodged with the BA1. Change a drawing after the BA3 is signed and the certificate no longer covers what you are building.
That is the most common way a certified application goes wrong. Somebody revises a window schedule or moves a wall after certification and nobody tells the surveyor.
Who Can Sign a BA3
Only a registered building surveyor. Not your draftsman, not your builder, not your engineer.
You can engage a private one, which is the certified route, or rely on your council’s, which is the uncertified route.
What It Costs
The BA3 itself is not a prescribed government fee. It is a professional fee charged by the building surveyor, and it varies with the complexity of the job.
For residential work, budget roughly $400 to $650 for a straightforward certificate. More where the design carries variations, a performance solution, or unusual construction.
That fee is separate from the council’s prescribed application fee, which is 0.19% of the value of the work for a certified Class 1 or Class 10 application.
What Happens If a Surveyor Will Not Sign
They will tell you what does not comply, and you fix it.
This is the underrated advantage of the certified route. A surveyor declining to certify is a private conversation and a revision. A council refusing an application is a refusal on the record.
Where the design departs from a deemed-to-satisfy provision, a performance solution may be available. That is prepared by a suitably qualified person and has to be accepted by the surveyor issuing the certificate. It is not a workaround, it is a different and more rigorous standard of proof.
Where the BA3 Sits in the Process
- Design and drawings prepared
- Planning approval, where required. See council approval
- Building surveyor assessment and certificate of design compliance
- Building permit application lodged with your council
- Permit issued, work commences
- Notice of completion lodged when finished
Full detail on the permit itself: building permits
The Other Forms You Might Meet
| Form | What it is |
| BA1 | Application for building permit, certified |
| BA2 | Application for building permit, uncertified |
| BA3 | Certificate of design compliance |
| BA5 | Application for demolition permit |
| BA7 | Notice of completion |
| BA8 | Notice of cessation |
| BA9 | Application for occupancy permit |
| BA13 | Application for building approval certificate |
| BA17 | Certificate of construction compliance |
| BA18 | Certificate of building compliance |
| BA19 | Request to amend building permit or builder’s details |
| BA20 | Notice and request for consent to encroach or adversely affect |
| BA22 | Application to extend time, building or demolition permit |
| BA23 | Application to extend time, occupancy permit or building approval certificate |
Also see the BA1 form , the BA2 form, certificates of design compliance explained
BA3 Questions
What is a BA3 form?
The certificate of design compliance. A registered building surveyor signs it to certify that the design of a proposed building complies with the applicable building standards.
Who fills out a BA3?
A registered building surveyor. Not you, and not your draftsman.
Do I need a BA3 for a building permit?
You need one to lodge a certified BA1 application. On an uncertified BA2 the council’s surveyors issue the certificate as part of processing your application.
How much does a BA3 cost?
It is a professional fee rather than a prescribed one. Budget roughly $400 to $650 for straightforward residential work, more where there are variations or a performance solution.
What is the difference between a BA3 and a BA18?
A BA3 certifies a proposed design before you build. A BA18 certifies an existing building, and is used for unauthorised work, a change of classification, or built strata.
Can I change the plans after the BA3 is issued?
Not without going back to the surveyor. The certificate covers the specific documents it references. Revised drawings are not certified.
