What is the DIY owner builder path?
In Victoria, an owner builder is someone who takes on the role of builder for construction on their own property. You don't need to be a licensed builder — but you do need an Owner Builder Permit from the Building And Plumbing Commission (BPC) formerly known as Victorian Building Authority (VBA) for projects over $16,000, and you still need a building permit for the structure itself.
Our DIY kit path is designed for homeowners who are comfortable managing a construction project and sourcing their own trades, but who want the prefab structure supplied to a known specification — and who want the complex permit and compliance paperwork handled professionally. Browse our prefab granny flat designs to see the models.
The core idea
We supply the factory-built modular components and manage all permit documentation. You coordinate the foundation, trades, and installation. The parts that require a licence — plumbing, electrical, roofing — still need licensed tradespeople, but you choose who you hire and negotiate directly with them.
What's in the kit — and what's not
Our prefab kit price is fixed per model. Understanding exactly what it covers helps you budget the variable site costs accurately.
Included in the kit (fixed price)
- Structural wall panels — factory-assembled
- Roof structure (framing and sheeting)
- Internal wall lining and ceiling
- Insulation (walls, ceiling, floor) to 7-star NatHERS standard
- Windows and external doors, pre-fitted
- Kitchen cabinetry and benchtop
- Bathroom fixtures and waterproofing
- Internal flooring
- Standard external wall cladding (fibre cement sheet, site-fitted)
Site costs (variable — quoted separately)
- Foundation and slab — varies by soil class, slope, and excavation required
- Roof plumbing — stormwater discharge connection to drain or retention tank
- General plumbing — hot and cold water connection from existing mains
- Mechanical plumbing — air conditioning installation and connections
- Electrical — switchboard connection, downlights, stove, sub-board if required
- External cladding upgrade (optional) — James Hardie or equivalent premium system
- Transport — standard metro Melbourne rate; regional Victoria incurs additional freight
Bushfire Prone Areas — cladding note
If your property is in a Bushfire Prone Area with a BAL rating of BAL-12.5 or above, the external wall cladding specification may be required to meet AS 3959 fire resistance requirements. This can affect whether the standard fibre cement sheet is sufficient, or whether a specific rated system must be used. We confirm this during your feasibility assessment. Read more about BAL ratings →
What you can DIY — and what must be licensed
Victorian law is clear on which work requires a licensed tradesperson. As an owner builder, you can perform a wide range of construction tasks yourself, but certain work must be carried out — and signed off — by licence holders. Getting this wrong can void your building permit and create issues with your occupancy certificate.
What Waverley handles for you
Even on the DIY path, the permit and compliance work is the most technically demanding part of any granny flat project. This is what we manage on your behalf:
- Site feasibility check — overlays, zoning, access, services
- Coordination with independent architects for drawings and documentation
- Structural engineering and soil test coordination
- NCC 2022 compliance documentation
- 7-star NatHERS energy report
- Building permit application submission to Registered Building Surveyor
- Guidance on mandatory inspection stages
- Technical support during installation
What we don't do on the DIY path
We don't manage your trades, schedule your inspections, or coordinate your site. That's your role as owner builder. What we do is make sure you have everything you need — the right documentation, the right kit, and clear guidance — so your project doesn't stall at the permit stage.
Getting your owner builder permit from the BPC
Before you can act as an owner builder in Victoria, you need an Owner Builder Permit from the Building and Plumbing Commission for projects over $16,000. The process involves completing a short online course and submitting an application. You can only be an owner builder on a property you own and intend to occupy.
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1
Check eligibility You must be the registered owner of the property. You can only apply for one owner builder permit per property every 5 years.
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2
Complete the BPC owner builder course A short online course covering your legal responsibilities, what work you can do, and how to manage trades. Available through the BPC website.
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3
Apply for your Owner Builder Permit Submit your application and course completion certificate to the BPC. Processing typically takes 1–2 weeks.
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4
Apply for your building permit With your Owner Builder Permit issued, we asssit you to submit the full building permit documentation package to the RBS.
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Build Once the building permit is issued, the kit ships and your site work begins. You coordinate your trades; we support with technical guidance.
Selling within 6 years
Owner builders in Victoria who sell their property within 6 years of obtaining the owner builder permit are required to obtain a Defects Inspection Report and take out Domestic Building Insurance (where applicable). This is worth considering if you may sell in the near future. We recommend speaking to a conveyancer about this before proceeding.
Frequently asked questions
Can I import a prefab granny flat kit directly from China myself?
You can import building materials, but you cannot simply buy a prefab kit from overseas and install it. For the dwelling to receive a building permit and occupancy certificate in Victoria, the structure must comply with the State Legislations, the NCC 2022 and all relevant Australian Standards. This requires full engineering documentation, a compliant energy report, and a Registered Building Surveyor to assess and approve the design. A kit without this documentation will not receive a permit — and building without a permit is not a legal path to an occupiable dwelling.
Our kits are designed and documented for Australian compliance from the outset, which is why the permit process is manageable and predictable.
How much can I save compared to a full package?
It depends on your site, your access to trades, and how much labour you can contribute yourself. The primary saving on the DIY path is in trade coordination and project management margins. Homeowners with connections to reliable trades — or trades in the family — tend to get the most value from this path. We can walk you through a realistic comparison during your consultation.
What if my soil test comes back with difficult conditions?
Soil classification in Victoria ranges from Class A (stable, sand or rock) through to Class E (highly reactive clay) and Class P (problem sites). Higher classifications require more engineered footings, which increases the foundation cost. We share the soil test results with you and the structural engineer designs appropriate footings. There are no surprises — the footing design is fixed before you commit to construction.
Do I need to be on-site during the build?
As the owner builder, you are legally the responsible party for the project. You don't need to be physically present every day, but you are responsible for ensuring licensed trades are used where required and that mandatory inspections are booked and passed. Most owner builders treat it like managing a renovation — involved, but not necessarily full-time.
Can I do this in regional Victoria?
Yes — our kits can be delivered across Victoria. Regional deliveries incur an additional freight cost depending on distance and access. In regional areas, sourcing licensed trades locally is your responsibility as owner builder. We recommend confirming trade availability in your area before committing to the project, as some regional areas have limited availability for certain specialists.