Often yes, where the dwellings are on land you own and you intend to live in one — but rules vary by state, and building multiple dwellings to sell can cross the line into work that needs a licensed builder.
The general position
Several states allow an owner-builder permit to cover a dual occupancy or secondary dwelling on your own land — NSW, for example, names dual occupancies and secondary dwellings in its permit scope, though a dual-occupancy permit is typically only granted in special circumstances, not as a matter of course. The consistent condition is that it’s genuinely your project on your land, not a development built to sell.
Where owner-builders get caught
- The “for sale” line. Owner-builder schemes exist for owner-occupiers. Building two dwellings to sell both looks like spec-building, which regulators treat as licensed building work — with penalties for doing it under an owner-builder permit.
- Resale restrictions. Most states cap how often you can be an owner-builder (commonly once every 5–6 years — NSW is 5 years, QLD is 6) and impose disclosure and warranty obligations if you sell within a set window. A duplex you split and sell can trip these.
- Planning approval. Dual occupancy is a planning question before it’s an owner-builder one — the development consent or CDC has to permit it.
Check your state before you commit
The answer genuinely turns on your state and your intent. Start with your state’s permit guide — NSW, QLD, VIC — and if you’re anywhere near the “building to sell” line, get it checked before you apply.