How we estimate air conditioning replacement cost
Every estimate combines a national price for each part of the job with a local labor adjustment for your state. Here is exactly how that works and where the numbers come from.
The formula
For each line item we multiply a quantity (driven by your conditioned home area, system type, efficiency tier, and whether ductwork is replaced) by a national unit cost, then apply a quality-grade factor. A regional labor multiplier is applied to the labor portion only — materials are priced nationally. We show the itemized result as a ±22% range.
National unit costs
| Line item | National unit cost | Source |
|---|---|---|
| Outdoor condenser unit | $2,700.00 / m² | ref |
| Furnace / heating unit | $2,000.00 / m² | ref |
| Evaporator coil / air handler | $2,250.00 / m² | ref |
| Refrigerant lineset & connections | $900.00 / m² | ref |
| Ductless mini-split (outdoor + heads) | $2,900.00 / m² | ref |
| Ductwork replacement | $30.00 / m² | ref |
| Installation labor | $2,200.00 / m² | ref |
| Permit, disposal & startup | $900.00 / m² | ref |
Regional labor multipliers
Each state's labor multiplier is its private-sector all-industry full-time adult ordinary-time weekly earnings relative to the national private-sector mean, from ABS Average Weekly Earnings (November 2025, Table 14, by state) — used as a proxy for HVAC-mechanic labour because Australia publishes no refrigeration & air-conditioning mechanic (ANZSCO 342111) by-state earnings series in public form, and the private-sector cut strips out the public-service distortion that inflates all-industry figures in the ACT. Multipliers are bounded to a sane range and applied to the labor share of each line item, so materials stay nationally priced while labor tracks local wages.
Data vintage & limitations
Compiled June 2026 from public cost aggregators and government wage data — these are derived estimates, not live contractor quotes. Local prices vary with project complexity, access, and material availability; always confirm with a licensed contractor before budgeting.