At a Glance
Ducted air conditioning in Australia typically costs $8,000–$22,000 per system, using Sydney metro as the baseline. Perth and Adelaide tend to run 10–15% higher due to smaller trade pools and logistics costs. The final price depends on house size, roof space access, zoning configuration, and whether existing ductwork can be reused.
What's Included
A standard ducted air conditioning installation covers:
- Supply of the outdoor compressor unit and indoor fan coil unit
- Ductwork fabrication and installation throughout the roof space to AS 4254.1 Ductwork for Air-Handling Systems
- Ceiling diffusers (vents) and return air grilles in each zone
- Refrigerant piping between indoor and outdoor units
- Electrical connection and dedicated circuit wiring to AS/NZS 3000 Wiring Rules
- Controller (wall-mounted or smart thermostat) installation and commissioning
- System testing, balancing airflow across zones, and handover
Materials (unit, ductwork, diffusers, refrigerant piping) typically make up 50–60% of the total. The remainder is labour, electrical work, and commissioning.
What Affects the Cost
- House size and number of zones. A 3-bedroom home with a single zone is a fundamentally different job to a 5-bedroom home with 4 zones. More rooms means more ductwork, more diffusers, and a larger capacity unit.
- Roof space access. The indoor unit needs at least 500mm clearance in the roof cavity. Low-pitch roofs, cathedral ceilings, or cluttered roof spaces add significant labour time or may require alternative mounting solutions.
- New installation vs replacement. Replacing an existing ducted system reuses existing ductwork routes and penetrations, saving 30–40% compared to a full new install. However, old ductwork (15+ years) may need replacing due to degraded insulation and loose joints.
- Zoning configuration. A basic single-zone system cools the entire house at once. Multi-zone systems (2, 4, or 8 zones) use motorised dampers to direct airflow to specific areas, adding 20–30% to the cost but reducing running costs substantially.
- Single-phase vs three-phase power. Systems above 12kW typically need three-phase power. If your home is on single-phase, the three-phase upgrade is a separate and significant additional cost.
- Insulation quality. A well-insulated home needs a smaller capacity system. Poor insulation means oversizing the unit, which costs more upfront and more to run.
- Brand and efficiency rating. Premium brands (Daikin, Mitsubishi Electric) with higher energy star ratings cost more than budget options but deliver lower running costs and longer warranties.
- Existing ductwork condition. If existing ductwork has degraded R-value, condensation damage, or loose joints, it needs replacing alongside the new unit. This is common in systems over 15 years old.
A straightforward replacement in a single-storey, 3-bedroom home with good roof access, existing ductwork in serviceable condition, and single-zone control sits toward $8,000. A new installation in a 5-bedroom, two-storey home with limited roof access, 4-zone control, three-phase power upgrade, and premium brand unit pushes toward $22,000.
City and Regional Price Comparison
Prices vary across Australia due to differences in labour rates, climate demands, housing construction, and trade pool size.
At the city level, Sydney is the baseline at $8,000–$22,000 per system. Melbourne tracks close to Sydney pricing, with the added factor that reverse-cycle ducted systems are standard (used for both heating and cooling year-round). Brisbane's subtropical climate means heavy cooling loads and larger capacity systems, but timber-framed construction makes installation easier. Perth and Adelaide typically run 10–15% above eastern capitals, reflecting higher trade rates, smaller installer pools, and extreme summer heat that drives demand.
Within any city, the range shifts based on home size, roof construction, and system complexity. Newer estates in outer suburbs with open roof cavities, modern insulation, and pre-wired electrical tend to sit at the lower end. Established inner-city homes with low-pitch roofs, limited cavity space, or heritage restrictions push costs higher. Two-storey homes add complexity regardless of suburb — running ductwork between levels is significantly harder than a single-storey roof space install.
How We Calculate
Estimates are based on surveyed trade rates for licensed air conditioning technicians holding ARC (Australian Refrigeration Council) authorisation, adjusted for each state and property type. All prices include GST. Figures reflect standard residential ducted air conditioning systems. Commercial installations and specialised applications are not included.