When to replace a skylight instead of repairing it
Replace the skylight when the unit itself has failed. Four signs make that call:
- Cracks, crazing or heavy yellowing in an acrylic dome.
- Fogging between glass panes, which means the seal has failed.
- A curb or deck below that is soft or rotted.
- Leaks that return after a proper reflash.
A leaking skylight with intact glass is a repair. Our skylight repair page explains reseal and reflash options. We resealed three skylights for one Alameda customer instead of replacing them, and we say plainly when a unit is past saving.
Replace an old skylight with a reroof: the timing question
The easiest time to swap a skylight is during a reroof. The shingles around the unit are already coming off, the curb is exposed, and new flashing laces into new roofing in one pass. Doing it separately means disturbing a finished roof and matching the covering around the unit afterward.
One Alameda customer had a skylight replaced with a reroof. If the roof is five years old and one unit is failing, replacement alone is entirely workable. The surrounding courses of shingle are lifted and rebuilt carefully, and we match what is there.
Skylight types: dome, curb-mounted and deck-mounted
New skylight replacements come in a few forms, and the existing roof usually decides.
- Acrylic dome: common on flat and low-slope roofs, set on a curb, the lowest cost.
- Curb-mounted glass: a framed unit on a raised curb, good on flat roofs and on shingle roofs with an existing curb.
- Deck-mounted: flashes directly to the roof deck on a pitched roof, with a factory kit.
- Venting: opens to move air, which suits a bathroom or kitchen.
For acrylic dome skylight replacement, the dome lid is sometimes the only piece that needs to change. If the curb is sound, a new lid on the old curb is the quickest fix. If the curb is flaking, we rebuild it. A curb mounted skylight on a flat roof also has to be tied into the membrane, which the same roofers do in the same visit.
What a skylight replacement includes
- Inspection of the unit, curb, deck and light well
- Removal of the old unit and its flashing
- Curb or deck repair, priced before work continues
- The new unit, set and flashed into the roofing
- Light well finish and interior cleanup
- Photos and a walkthrough
Can the new skylight fit the existing opening?
A same-size replacement fits the existing opening, and a bigger one means framing. Measure the opening at the roof deck, not at the ceiling, because the light well often tapers. Manufacturers list rough-opening sizes for each model, and the estimate should match the new unit to the old frame.
Adding a brand-new opening where none exists is a different job, covered on the skylight installation page. Going larger than the old opening changes everything: rafters are cut and headered, the light well is rebuilt, and the permit question grows. Going smaller is easier. Each of those is a line in the estimate, not a surprise at tear-off.
Our skylight replacement process
- Inspect the unit, curb, deck and light well from the roof and from inside.
- Write the estimate with the unit model, curb work and flashing listed, and with reroof and stand-alone options priced if both apply.
- Confirm who pulls the permit, and order the unit.
- Protect the room below and remove the old unit.
- Repair the curb or deck after you approve any change order.
- Set the new unit, flash it into the roofing, and seal it.
- Test the joint, wipe down the unit and light well, and clear debris.
- Send photos and walk the finished work with you.
What does skylight replacement cost?
Skylight replacement cost depends on the unit, curb or deck work, roof covering, access and the light well finish. The most expensive part is rarely the glass. It is the framing, the flashing and the work to get at the opening. Unit prices vary by model and we have no verified local figure to quote.
Doing the swap with a reroof tends to lower the labor on the flashing, since the roof is already open. Ask for the unit, curb, flashing and interior finish as separate lines so you can compare bids. Hold every bid to its written estimate, and any rot found when the old unit comes off is explained as a change order before work continues.
Is a skylight replacement a good time to add venting or change the glass?
A swap is a fair moment to reconsider the unit. A fixed unit in a steamy bathroom can be replaced with a venting model, though a venting unit needs power or a manual crank. Low-emissivity glass and tinted glazing reduce heat and fading in a west-facing room. These choices change the size and cost, so settle them before ordering.
Permits, energy labels and licensing for a swap
Replacing a skylight brings more paperwork than resealing one. BayREN's 2025 permit guide for windows and skylights says replacement units must meet energy-code limits for heat loss and solar gain, proven by the NFRC label, and the label should stay on the unit until final inspection. Whether a like-for-like swap needs a permit is the City of Alameda Permit Center's call, and the estimate should say who pulls it. Roofing work needs a C-39 classification, so check the license, bond and workers' compensation status at cslb.ca.gov. Before you pay anything, know that California limits a down payment on a home improvement contract to $1,000 or 10% of the price, whichever is smaller (Business and Professions Code §7159.5).
Where we replace skylights
From our Webster St office, Oakland is about 12 minutes away, Berkeley roughly 18, San Leandro about 24 and Hayward around 31, with bridge traffic adding variability. Alameda itself, about 66 rainy days a year in ZIP 94501 (BestPlaces), is why a failing unit gets attention before October.