Attic fan installation cost: roof-mounted power vents, by state
One large roof-mounted attic fan: about $1,100 to $1,750, typically $1,350. That's a new roof-mounted power attic vent fan set in the roof and wired with its own 110 volt run, plus the contractor's overhead, profit and sales tax. Roof repairs around the opening, a new circuit at the panel, a whole-house fan and permits are extra.
Anthony Hicks30+ years in construction. Updated November 5, 2026.
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What it costs
| Job | Cost |
|---|---|
| One roof-mounted attic fan | $1,050 to $1,650 |
| One large roof-mounted attic fan | $1,100 to $1,750 |
| Two roof-mounted attic fans | $1,250 to $1,850 |
Totals include the contractor's overhead and profit (20%) and the state's average sales tax. Prices as of November 2026.
What’s in these numbers
Each total is a typical job, priced the way a contractor’s estimate is priced:
| One fan | One large fan | Two fans | |
|---|---|---|---|
| Fan | A roof-mounted power attic vent | A large roof-mounted power attic vent | Two roof-mounted power attic vents |
| Power | A 110 volt wiring run and box | Same | One run and box for each fan |
On top of the work:
- Overhead and profit: 20%, the standard markup on a contractor’s estimate.
- Sales tax on the materials, at the state’s average rate.
Not in them: roof repairs around the opening beyond the fan’s flashing, a new circuit at the panel, a thermostat or humidistat upgrade, a gable-mounted or whole-house fan, and permits.
How attic air moves
An enclosed attic needs cross ventilation (IRC R806.1): net free vent area of at least 1/150 of the attic’s floor area, or 1/300 where 40 to 50% of it is high, within 3 feet of the ridge, with the rest low, and, in climate zones 6, 7 and 8, a Class I or II vapor retarder is on the warm side of the ceiling (IRC R806.2). Air comes in low through the soffit vents and leaves high. A power fan pulls that air out faster; the roof vents guide and the ridge vent guide cover the passive vents it works with, and the soffit guide the intake.
What moves the price
- How many and how big. Each fan adds its unit and a wiring run, but a second fan on the same visit adds far less than the first: the trip and setup are already paid for.
- The roof. Cutting into tile, metal or a steep roof takes longer than shingles on a walkable pitch.
- Power. A wiring run from a nearby box is in these totals; a new circuit from the panel is not.
- Where you live. Pick your state in the box above.
Common questions
How much does it cost to install an attic fan?
About $1,050 to $1,650 for one roof-mounted fan wired in, typically $1,300.
How much is a large attic fan installed?
About $1,100 to $1,750, typically $1,350.
How much for two attic fans?
About $1,250 to $1,850, typically $1,500.
Is an attic fan the same as a whole-house fan?
No. An attic fan exhausts the attic’s air through the roof; a whole-house fan pulls air from the living space up into the attic and out through its vents.