Owner-Builder vs Builder: Cost Compared
The question every homeowner doing a Queenslander renovation eventually faces: should I go owner-builder or engage a licensed builder to manage the project?
The honest answer depends on your situation: here’s what the numbers actually looked like on a real Coorparoo project. Figures are from a 2018-2020 build. How to use them →
What the saving was (and where it came from)
An owner-builder saves money by avoiding the builder’s margin: the percentage a licensed builder adds on top of trade costs to cover their overhead, risk and profit. In the Brisbane residential construction market, builder’s margins typically run 15-25% of project cost. On a large project, that compounds quickly.
On the Coorparoo project, managed as owner-builder, the total cost was $331,510. The builders we approached for fixed-price quotes were well over $500,000 for the same scope. The estimated saving was roughly $200,000, around 33% of what a builder-managed equivalent would have cost.
What the comparison actually looks like
| Item | Owner-builder | Licensed builder |
|---|---|---|
| Builder’s margin | None (you are the builder) | 15-25% on top of trade costs |
| Coorparoo project cost (112.5 m² enclosed build-under) | $331,510 actual | $500,000+ quoted |
| Estimated saving | ~$200,000 (~33%) | - |
| Your time commitment | Part to full-time during active stages | Minimal |
| Legal responsibility | You, as owner-builder | Builder (to extent of contract) |
| Risk management | You | Builder |
| QBCC permit required | Yes | No |
| 6-year resale restrictions | Yes | No |
What owner-building actually costs you in time
Managing a Queenslander raise and build-under as owner-builder is not a passive exercise. Expect:
- 10-20 hours/week during planning and approval stages
- 20-40 hours/week during active construction (raise, slab, frame)
- 10-15 hours/week during lining, fit-out and close-out
If you are working full-time in another role, this is a significant additional commitment. The financial saving must be weighed against the personal cost.
What a licensed builder manages for you
When you engage a licensed fixed-price builder, they:
- Source and coordinate all trades
- Manage the hold points and inspection schedule
- Handle most variations (subject to contract terms)
- Absorb the risk of trade delays and scheduling conflicts
- Sign off on compliance as the licensed responsible party
- Provide statutory warranty on the completed work
When you go owner-builder, all of this becomes your job.
When owner-building makes sense
Owner-building tends to work well when:
- You have time to manage the project actively
- You have some prior construction or project management experience
- You are not working to a tight deadline
- The financial saving is material to the project viability
- You are prepared to accept personal legal responsibility
It works less well when:
- You have limited time or construction familiarity
- You are working to a fixed completion date
- You plan to sell within six years
The Coorparoo experience
On the Coorparoo project, going owner-builder was the right decision: the saving was material, the time was available and the experience was genuinely valuable (even the painful parts). But it was not a passive experience. Managing trades, attending hold point inspections, handling variations and keeping the paperwork in order took significant time and energy over 18+ months.
The 33% saving estimate is accurate. The time cost is also accurate.
Owner-builder vs builder: FAQ
How much can I save by going owner-builder on a Queenslander build-under?
On our Coorparoo project we estimated the saving was about $200,000 compared to the builder quotes we received (which were well over $500,000 for the same scope). Your saving will depend on current Brisbane builder margins, current trade rates and the scope of your project. As a typical figure, owner-builders save around 25% on a comparable scope; the Coorparoo result reflects procurement choices specific to that project.
Is it worth going owner-builder if I have a full-time job?
It depends. If you have flexibility in your working hours and a patient employer, it can be done. But during active construction stages, the coordination and admin burden is significant. Many people underestimate it. Be honest about your available time before deciding.
What happens if something goes wrong as an owner-builder?
As the owner-builder, you are the licensed responsible party. If something is non-compliant or defective, the responsibility sits with you. You cannot simply call the builder and demand they fix it. This is the primary risk of the owner-builder path.
Can I use a licensed builder for some stages and owner-build others?
This is complex and depends on how your QBCC permit is structured. In general, the permit covers the whole project: you can engage any licensed trade, but you remain the responsible party throughout. Get specific advice from QBCC for your situation.
Practical tool
Get the Build-Under Budget Toolkit: $79
The full Coorparoo line items as the starting reference plus quote entry worksheets, a trade payment schedule template, a contingency calculator and a glossary of cost categories. Designed for use through your own project.
One-time purchase. Instant download. 30-day refund.