Skylight replacement cost depends on the size and type of the unit, the curb, the flashing, the glazing, the roof it sits in and how hard the roof is to reach. There is no honest single number. A leak often costs less to fix by resealing flashing than by replacing the unit, and replacing a skylight during a reroof usually avoids paying twice for the same roof work.
What factors set the price of a new skylight?
Six things matter most, and each is something you can ask about in an estimate.
| Factor | Why it changes the price |
|---|---|
| Size | Larger units cost more and need more framing work |
| Type | Fixed, venting and dome or tubular units differ in cost and install |
| Curb | A curb-mounted unit needs a raised frame and its own flashing |
| Flashing kit | Roof type decides the kit and the labor to integrate it |
| Glazing | Glass type, tint and energy performance affect the unit price |
| Access and roof | Steep pitch or a tile or metal roof raises labor |
Interior work is separate from the roofing price. If the opening changes size, the ceiling shaft needs framing and finish, and a different trade usually does the drywall and paint. Ask for a written scope that says where the roofer's work ends.
Should you repair or replace a leaking skylight?
Start with the flashing. CSLB's roofing guide notes that interior water damage is commonly caused by poorly installed flashing around chimneys and skylights, and that these problems do not necessarily mean a new roof. The same is often true of the skylight itself: the glass may be sound while the sealant or flashing has failed.
Customers report both outcomes in Alameda. On one job the flashing was resealed on three skylights instead of replacing them. A garage skylight leak was patched the next day on another. And one skylight leak showed up after another roofer's reroof, which is a reminder that skylight flashing is a detail that is easy to get wrong.
| Finding | Likely fix |
|---|---|
| Dried or cracked sealant, sound unit | Reseal or reflash |
| Flashing lifted or poorly layered | Reflash with the roofing |
| Fogged or cracked glazing | Replace the glazing or the unit |
| Rotted curb or wet framing | Replace the curb and unit, repair framing |
| Cracked plastic dome | Replace the dome unit |
Why does timing with a reroof matter?
A skylight replaced with the roof saves duplicate labor. The shingles around the unit are already coming off, so the flashing can be woven into the new layers instead of patched against old roofing. Doing the roof first and the skylight later means cutting into new material.
One Alameda customer had a skylight replaced as part of a reroof. If your skylight is old and your roof is near the end of its life, ask for the skylight priced as its own line in the reroof estimate, and compare it with a stand-alone replacement. The line item lets you see the cost and decide.
How does a skylight replacement run, step by step?
Every job follows the same order, and each step is a place where cost can change. A typical sequence:
- Measure the existing opening and curb from the roof and from inside, and confirm the unit size and type.
- Protect the room below with covers, since removing a unit opens the roof directly to the room.
- Remove the old unit and flashing, and check the curb, framing and decking for rot or moisture.
- Repair any damaged framing or decking, which is billed separately when it was not in the original scope.
- Set the new unit, then lay underlayment and flashing in layers that shed water over each other.
- Check the finished work from inside and outside, then clean up and haul away the old unit.
Step 3 is the one that changes the price. Many skylight leaks leave the curb damp for years, and a soft curb means the unit cannot just be swapped. A written change order for hidden rot, explained before work continues, is the standard to hold a roofer to.
Does a skylight swap need a permit in Alameda?
Possibly, and the answer depends on what changes. The City of Alameda says permits are needed for most construction work, and that changes to the exterior of a building, including windows, need both a permit and Planning Design Review approval. A new or larger opening is a bigger change than a swap in the same opening, so ask the Permit Center how it treats your project, and make sure the estimate says who pulls the permit. If the skylight is replaced during a reroof, the permit question is handled together with the roof work.
Which skylights are worth replacing with the roof?
Replace the ones you cannot trust, and reseal the ones you can. Use this as a decision frame when you price a reroof:
| Skylight condition | Reroof decision |
|---|---|
| Original unit, fogged glass or cracked dome | Replace with the roof |
| Leak history, curb sound, flashing worn | Reflash with the roof, replace only if the seals failed |
| Newer unit, sound seals, no leaks | Keep it, with new flashing integrated |
| Rotted curb or framing | Replace the curb, and likely the unit |
| Unit you never use for light or venting | Ask about options before paying to replace it |
A skylight left behind under a new roof is a leak risk because old flashing sits next to new shingles. Ask the roofer to say, in writing, what they plan to do with each skylight, and why. That one line in an estimate prevents a lot of disputes later.
What about dome and tubular skylights?
Dome skylights are the simplest and usually the least costly to replace, because the unit sits on a small curb or flange and the flashing is straightforward. Plastic domes can crack or cloud with age, and the flange seal around them can fail first. A roofer should look at the seal and the curb before recommending a new dome.
Tubular units are small, but the flashing at the roof and the tube run through the attic still need care. Ask whether the existing tube can be reused, and whether the work involves the attic insulation. In either case, the estimate should say whether the unit is replaced in the same opening or in a new one.
What does a good skylight estimate include?
It should name the unit, the size, the curb type, the flashing method and what happens to the old unit. Look for these items:
- Make and model of the replacement, or the specification
- Whether the existing curb is reused or replaced
- Flashing method and materials
- Allowance for rotted framing or decking
- Cleanup and disposal
- Who pulls any permit, which the estimate should state
The terms go in your contract in writing. Ask us before you sign. CSLB advises comparing at least three bids and not letting payments get ahead of the work.
What do we see on skylight jobs in Alameda?
Skylights come up in Alameda customer reviews. Pedro sealed a small skylight leak from the truck before the customer had even hired us. On leaking skylights, repair was favored over replacement, which is the honest answer when the unit itself is sound.
Our skylight replacement page explains how a replacement visit works, the skylights hub covers the full range, and skylight repair explains when a reseal is enough. If the skylight is in Alameda, the home page explains how our visits work.
Whatever the range you find online, your written estimate is the number that counts. Call the office or ask for a free inspection, and tell us how many skylights you have and where they leak.