Skylight Installation Cost: Estimating New and Replacement Units

Skylight installation is priced by unit type, roof construction, and how much interior finish work the light shaft requires. Replacing an existing curb-mounted unit is a predictable half-day job; cutting a new opening through a finished ceiling is a multi-trade job.

What does skylight installation cost?

Replacing an existing skylight runs $600 to $1,800 per unit including flashing. A new fixed skylight with a drywalled shaft runs $1,500 to $3,500. Vented or motorized units run $2,000 to $5,000. Tubular skylights (light tubes) are $500 to $1,200 installed.

What factors move the price?

• Roof pitch and material — tile and metal cost more to flash than asphalt shingle
• Rafter cutting and headers required to widen the opening
• Attic depth: a deep, angled light shaft means more framing and drywall
• Finish work: drywall, mud, paint, and trim on the shaft
• Electrical for vented/blackout-shade units

How should you quote the shaft work?

Separate the roofing scope (opening, curb, flashing, weatherproofing) from the interior scope (framing the shaft, drywall, finish, paint). Homeowners underestimate the interior side, and an estimate that shows both prevents the "why is a window this expensive" conversation.

What leak-risk factors should the estimate flag?

Note the flashing method (a proper step-and-counterflashing kit, not caulk), the condition of the surrounding roof, and whether the roof is near end of life — installing a new skylight into a 20-year-old roof means you will be back when the roof is replaced. Recommend doing both together if the timing is close.