Short answer: approve a skylight replacement quote only after it states the opening size, curb or deck mount, roof slope, roofing material, flashing kit, underlayment, energy rating, leak repair, interior drywall work, cleanup, and warranty exclusions.
A skylight replacement sits at the intersection of roofing, daylighting, air sealing, and interior finish repair. A bid that only names the skylight unit may leave out the work that prevents leaks and drafts.
Energy.gov updated its skylight guidance in June 2026 and recommends choosing skylights based on energy performance ratings, climate, and home design. ENERGY STAR also points homeowners toward certified residential windows, doors, and skylights, while its 25C tax credit page says windows and skylights must meet ENERGY STAR Most Efficient criteria to qualify.
Start With Leak History And Roof Context
The contractor should note whether the skylight is being replaced because of age, broken glass, condensation, roof replacement, flashing failure, ceiling staining, air leakage, or a known roof leak.
A skylight can leak at the unit, curb, flashing, roof deck, nearby shingles, underlayment, or interior shaft. The quote should say what was inspected before pricing the job.
Confirm Opening Size And Mounting Type
The estimate should state rough opening dimensions, existing unit size, curb height, roof slope, shaft depth, and whether the replacement is curb-mounted or deck-mounted.
Changing the size or mounting type can trigger framing, drywall, insulation, roof deck, and finish work. If the contractor is reusing the opening, that should be written too.
Require Flashing And Underlayment Details
Skylight work fails when the flashing scope is vague. The quote should identify the flashing kit, step flashing, head flashing, sill flashing, apron flashing, ice-and-water membrane or self-adhered underlayment where used, and how the flashing ties into the roofing material.
If the roof is metal, tile, slate, low-slope, or unusually steep, ask whether the listed skylight and flashing system is approved for that roof type.
Check Energy Ratings And Glazing
Energy.gov says skylight labels can include U-factor, solar heat gain coefficient, visible transmittance, air leakage, and condensation resistance. The quote should identify the glazing package and performance ratings, not just “energy efficient glass.”
If a tax credit or rebate is mentioned, ask for the exact product documentation. ENERGY STAR says qualifying windows and skylights must meet ENERGY STAR Most Efficient criteria for the 25C federal tax credit.
Separate Roof Work From Interior Finish Work
The quote should say whether it includes shingle removal and replacement, roof deck repair, rotten curb repair, shaft insulation, air sealing, drywall patching, texture, paint, blind or shade removal, and interior cleanup.
Many skylight quotes stop at “watertight exterior installation.” That may leave stained drywall, damaged paint, or unfinished shaft work outside the price.
Consider Lead-Safe Work In Older Homes
If interior painted surfaces will be disturbed in a pre-1978 home, ask whether EPA Renovation, Repair and Painting requirements apply. This matters when drywall, trim, old paint, or ceiling surfaces are cut or repaired.
Lead-safe work should be a written part of the quote when applicable, not a verbal reassurance after demolition starts.
Skylight Quote Review Table
| Quote area | What to confirm | Why it matters |
|---|---|---|
| Diagnosis | Leak source, condensation, broken glass, roof age | The repair should solve the actual failure. |
| Fit | Opening size, curb/deck mount, roof slope, shaft depth | Fit determines labor and compatibility. |
| Flashing | Kit, step flashing, head/sill flashing, underlayment | Water control depends on the full assembly. |
| Performance | U-factor, SHGC, VT, air leakage, condensation resistance | Ratings affect heat gain, heat loss, and comfort. |
| Interior | Drywall, insulation, air sealing, paint, cleanup | The finished room may need more than roof work. |
Questions To Ask Before Approval
- What caused the leak, stain, condensation, or failure?
- Is the skylight curb-mounted or deck-mounted?
- What are the opening size, roof slope, and roof material?
- Which flashing kit and underlayment are included?
- Are rotten curb, roof deck, or framing repairs included?
- What energy ratings and glazing package are listed?
- Will interior drywall, insulation, air sealing, and paint be repaired?
- Does lead-safe work apply to any disturbed painted surfaces?
- What product, glass, leak, and labor warranty applies?
Red Flags In A Skylight Estimate
- The quote says “replace skylight” but does not mention flashing.
- No roof slope or roofing material is recorded.
- The contractor cannot explain whether the unit is curb-mounted or deck-mounted.
- Energy performance is described with marketing words but no ratings.
- Interior drywall and paint repair are assumed but not written.
- A tax credit is promised without product documentation.
Quote check: a skylight is not just a window in the roof. The quote should define the roof-waterproofing assembly and the interior finish scope before installation starts.
Source Links
- Energy.gov: Skylights
- Energy.gov: Energy Performance Ratings for Windows, Doors, and Skylights
- ENERGY STAR: Residential Windows, Doors, and Skylights
- ENERGY STAR: Windows and Skylights Tax Credit
- Building America Solution Center: Windows and Skylights
- EPA: Lead Renovation, Repair and Painting Program
- FTC: How to Avoid a Home Improvement Scam
FAQ
Should a skylight quote include flashing?
Yes. The quote should identify the flashing system and how it ties into the roof material. Flashing is central to leak prevention.
What is the difference between curb-mounted and deck-mounted skylights?
A curb-mounted skylight sits on a raised curb, while a deck-mounted unit attaches closer to the roof deck. The existing opening and roof system usually determine the right scope.
Do energy ratings matter for skylights?
Yes. Energy.gov points to ratings such as U-factor, solar heat gain coefficient, visible transmittance, air leakage, and condensation resistance.
Should interior drywall repair be included?
Only if the quote says so. Skylight replacement can leave ceiling stains, shaft damage, texture repair, or paint touch-up outside the exterior installation price.
Can a skylight qualify for a tax credit?
Possibly, but ENERGY STAR says qualifying windows and skylights must meet ENERGY STAR Most Efficient criteria. Ask for product documentation before relying on the credit.