What Affects the Cost
Fan type and capacity. Basic ceiling-mounted bathroom fans are inexpensive. Inline fans like the
Fantech Rapid Response ($170–$290) mounted in the roof space are quieter, can serve multiple rooms via Y-junctions, and are well-suited to Brisbane's open-plan renovations.
Ducting requirements. Where ducting already exists and runs to the outside, a fan swap is quick. New ducting runs through roof spaces add time and materials. Rigid or semi-rigid ducting ($15–$25/m) resists sagging in Brisbane's hot roof spaces and lasts significantly longer than flexible foil ($8–$12/m), which deteriorates faster here than in cooler climates.
Number of rooms. Single bathroom extraction is straightforward. Adding fans to a second bathroom, ensuite, and laundry means multiple duct runs and discharge points.
Construction type. Brisbane's timber-frame and weatherboard housing stock is generally easier to work with than brick or masonry. Newer rendered block construction in suburbs like Springfield, North Lakes, and Coomera requires cutting through block walls for external vents.
Roof access and type. Most Brisbane homes have accessible roof spaces with reasonable clearance. Skillion roofs and low-pitch designs in newer builds can be tighter. Metal roofing is simpler to penetrate and seal than tiles.
Kitchen rangehood ducting. Ducting a rangehood to the exterior adds $300–$1,000 depending on duct length and exit point. In many Brisbane homes, ducting through the soffit or eaves avoids a roof penetration, which reduces leak risk given Brisbane's heavy summer storms.
Subfloor ventilation. Queenslander houses and other raised-floor homes may need subfloor fans to address dampness underneath. Systems like
Envirofan ($200–$600 for the kit, plus $300–$800 for professional installation) restore airflow and reduce conditions that attract termites.
A simple bathroom fan replacement with existing ducting and wiring sits toward $200. Installing exhaust fans in multiple bathrooms with new ducting to the roof, a ducted rangehood through an external wall, and subfloor ventilation fans in a Queenslander pushes toward $1,400.
Brisbane-Specific Considerations
Humidity regularly exceeds 70% in Brisbane's summers, and even in winter, ambient moisture levels stay higher than in Sydney or Melbourne. Bathroom mould is extremely common in homes without properly ducted exhaust fans. Once established, it returns within weeks unless the underlying ventilation problem is fixed. A humidity-sensing fan is more effective here than a fixed timer, because Brisbane's background humidity means a standard 15-minute timer often is not long enough to clear moisture after a shower.
The classic Queenslander presents ventilation needs found in no other Australian city. These raised timber homes across suburbs like Paddington, Red Hill, Ashgrove, and Woolloongabba were originally designed for natural airflow through high ceilings, wide verandahs, and open subfloor spaces. Over the decades, many have had their subfloor areas enclosed with skirtings, lattice panels, or landscaping that blocks air movement. The result is damp, musty conditions underneath the house that can attract termites and cause timber deterioration. Subfloor ventilation fans from brands like Envirofan (dual-fan systems extracting 3,250 L/min, quad-fan systems at 6,500 L/min) can be solar-powered, costing as little as $4 per year to run.
For bathroom ventilation in post-war housing across suburbs like Stafford, Kedron, Chermside, and Moorooka, flexible foil ducting installed in the 1990s or 2000s is often the weak point. Brisbane's hot roof spaces (regularly exceeding 60 degrees C in summer) accelerate deterioration of foil tape joints and the foil itself. If your existing ducting has sagged or separated at joins, replacing it with rigid or semi-rigid duct is a better long-term investment, even at the higher material cost.
Open-plan kitchen-living areas are standard in Brisbane renovations and newer builds across North Lakes, Springfield, and the Redlands. Without a properly ducted rangehood, cooking moisture and fumes spread through the entire living space. If you have a gas cooktop, the National Construction Code requires external ducting, so a recirculating rangehood is not compliant. Ducting through the soffit or eaves is often the simplest exit route in Brisbane, avoiding a roof penetration that could leak during summer storms.
Worth noting: Brisbane's metal roofing, common on both older and newer homes, is generally simpler and faster to penetrate and seal than tile roofing. A roof cowl installation on metal takes less time than on tiles, where surrounding tiles must be carefully lifted and replaced.
Hiring a Licensed Air Conditioning Technician in QLD
In Queensland, all electrical work must be performed by a licensed electrical contractor or licensed electrician. Ventilation installations involving hardwired fans, new circuits, or switch wiring fall under this requirement. Electrical licences are administered by the Electrical Safety Office (WorkSafe Queensland), while contractor licences are issued through the QBCC.
The electrician must provide an Electrical Safety Certificate on completion. A good installer will also specify the fan's extraction rate in the quote to confirm it meets AS 1668.2 minimums.
Worth checking:
Current Queensland electrical licence (verify on the QBCC website)
Electrical Safety Certificate issued on completion
Fan extraction rate specified (minimum 25 L/s for bathrooms)
Ducting material and discharge point confirmed before work starts
For Queenslanders, subfloor ventilation scoped separately from bathroom extraction
How We Calculate
Estimates are based on surveyed trade rates for licensed electricians and air conditioning technicians in the Brisbane metro area, adjusted for property age. All prices include GST. Figures cover standard residential exhaust fan and ventilation work. Commercial extraction systems, ducted air conditioning, and whole-house ventilation systems are not included.