What it costs
Every cost line below is free to see — knowing what exists is half the battle, and a budget that's missing a line is worse than one that's slightly off. The dollar ranges are the paid part.
Before you build
| Cost line | Notes | Range |
|---|---|---|
| Survey and site plan | Needed before design; also flags easements early. | |
| Design / drafting | Sketch through to construction drawings. | |
| BASIX certificate | Required for a new secondary dwelling. | |
| Bushfire assessment | Only if the land is bushfire-prone — but then it's not optional. | |
| Certifier fees (CDC) or council DA fees | Which one depends on your pathway. | |
| Long Service Levy | Payable above a project cost threshold. |
Construction
| Cost line | Notes | Range |
|---|---|---|
| Total build (turnkey), per m² | Whole-of-build guide covering frame, fit-out and finishes. Varies with spec and site. | |
| Site preparation and excavation | Slope drives this hard. | |
| Slab and footings | Soil classification matters here. | |
| Frame, roof and lock-up | ||
| Fire-rated construction | Only for attached builds — see the fire separation pack. | |
| AS 3959 bushfire construction | Scales sharply with BAL rating. | |
| Fit-out, kitchen, bathroom | ||
| Service connections (water, sewer, power) | Frequently underestimated; long lead times. |
The lines people forget
| Cost line | Notes | Range |
|---|---|---|
| Driveway / access and parking | May be a condition of approval. | |
| Landscaping and private open space | Often a requirement, not a nicety. | |
| Stormwater / drainage connection | ||
| Contingency | Hold a real one. Owner-builders routinely hold too little. |
Pay once and the figures are yours
Indicative cost ranges where a reliable public figure exists, plus the roadmap detail and the sourced eligibility material.