2026
The Melbourne
Renovation Index
Published cost bands for Melbourne extensions and renovations, with the method, the assumptions and the exclusions stated in full. Free to read, free to cite, no email required.
Base rates
| Scope | Basis | Rate |
|---|---|---|
| Ground-floor extension | New construction, basic shell and extended roofline | $2,700 – $5,100/m² |
| Second-storey addition | Shell rate plus AE Index first-floor uplift | $3,400 – $6,400/m² |
| Renovation within existing building | No structural upgrade assumed, good access | $1,600 – $3,900/m² |
Ground-floor and renovation rates: Archicentre Australia CostGuide 2026 · GST inclusive
Second-storey uplift: AE Index — Archicentre lists first-floor additions as an extra, not a rate
Wet areas
These sit outside the square-metre rate and are costed separately. This is the single most common reason a homeowner's own estimate comes in low.
| Room | Notes | Range |
|---|---|---|
| Kitchen | Highest cost per square metre in the house | $23k – $49k |
| Bathroom or ensuite | Full waterproofing and floor-to-ceiling tiling | $17.5k – $35k |
| Laundry | Excludes white goods | $10k – $19k |
Site adjustments
These are AE Index's own, derived from how Melbourne sites actually behave rather than from any published table. We publish them so you can disagree with them.
| Factor | Applies when | Adjustment |
|---|---|---|
| Inner-suburb location | Tight sites, higher labour rates, heritage density | ×1.20 |
| Middle-ring location | Larger blocks, easier delivery | ×1.10 |
| Heritage overlay | Confirmed on title | ×1.15 |
| No vehicle access | Materials hand-carried or craned | ×1.15 |
| Restricted access | Machinery fits, but barely | ×1.07 |
Allowances for the existing house
Work to the parts of the house you are not extending. Derived from published repair rates for restumping, rewiring and re-plumbing.
| Built | Typical condition | Allowance |
|---|---|---|
| Before 1940 | Restumping, rewiring and re-plumbing usually required | $26k |
| 1940 – 1990 | Partial services upgrade | $9k |
| After 1990 | Services generally compliant | Nil |
Added on top
| Item | Covers | Rate |
|---|---|---|
| Professional fees and permits | Architect, structural engineer, building surveyor, permit levy, energy rating assessment | 25% |
| Contingency | Undisclosed structural, drainage or waterproofing issues | 12% |
What is excluded
Landscaping and external works. Appliances, furniture and window furnishings. Council planning application fees. Driveway reinstatement. Temporary accommodation and storage. Hazardous material removal. And anything found once walls are opened — which is why the contingency line exists.
Run your own numbers
The estimator applies everything on this page to your scope, suburb and site conditions, and shows each line as it does.
Last updated 28 July 2026