Roof and exterior
Skylight installation cost
A standard fixed skylight cut into an asphalt roof over a 4 ft attic is about $2,032 installed, and the skylight is 22% of that. The rest is the hole: the roof cut and framed, a flashing kit for that roofing, 6.5 hours of a roofer, and a 49 sq ft light shaft framed, insulated, drywalled and painted down to the ceiling — which no quote from memory includes and which is more than the skylight. Into a vaulted ceiling it is $1,351; replaced on an existing opening $1,170; a sun tunnel $965; a leak reflashed $510. This reads the roof — pitch, roofing, rafter spacing — and the attic under it, and prices fixed, venting, electric and tubular new and replaced on one chart.
Written and edited by Pablo Ruiz Quintero
Last reviewed 2026-09-23 · Nothing you type leaves your browser
Skylight installation cost calculator
The skylight, the roof, and what is under it
The unit is a third at most. The roof decides the flashing and the hours; the ceiling decides whether there is a shaft to build.
Cut, framed, flashed, and the shaft built down to the ceiling.
Glass that does not open. Laminated or tempered, low-E, argon. The cheapest unit and the one on most roofs.
The size most are: two rafter bays long at 24 in, one bay wide.
Step flashing woven into the courses. The kit is made for it.
Deck-mounted, walkable.
Nothing is cut.
A light shaft from the roof to the ceiling: framed, insulated, drywalled, painted.
The shaft's height, roof to ceiling.
Straight down; lights a patch.
On the same visit.
About 6.5 hours on the roof.
Used only to pick a regional labour rate. It stays in your browser.
Fixed skylight, new opening
$2,032
the unit is 22% of it · 6.5 hours · 49 sq ft of shaft
You pay for the hole, not the glass
$450 of skylight and $1,582 of everything that makes it one: the roof cut and blocked, the flashing kit for asphalt shingles, 6.5 hours on a 6:12 roof, and $861 of light shaft — 49 sq ft of insulated, drywalled, painted wall through 4 ft of attic.
The shaft is the job
4 ft of attic is 49 sq ft of wall.
Between the roof and a flat ceiling is a tunnel that has to be framed, insulated like the exterior wall it is, drywalled, taped and painted — at $14 a square foot, more than the skylight above it once the attic is past 4 ft. Splayed, so the opening in the ceiling is bigger than the one in the roof, it is 40% more wall and lights the room instead of a patch of floor.
Each kind, new and replaced
This roof, this size, this attic — a new opening against a unit swapped on the existing one.
What the roofer charges for
- Fixed skylight, 21 × 46 in
Glass that does not open. Laminated or tempered, low-E, argon. The cheapest unit and the one on most roofs.$450 - Deck flashing kit for asphalt shingles
Step flashing woven into the courses. The kit is made for it.$170 - Blocking
Doubled headers and trimmers where a rafter is cut; blocking where it is not.$23 - Roofing around the opening
A bundle of matching shingles, underlayment and ice-and-water membrane around the opening.$60 - Cutting, framing, setting and flashing
6.5 hours on the roof.$468 - Light shaft, 49 sq ft of wall
Framed, insulated (it is an exterior wall in the attic), drywalled, taped and painted. Per square foot of shaft wall.$681 - Interior finish
The ceiling opening trimmed or corner-beaded, the drywall patched and painted around it.$180
What it costs
National average. One fixed skylight, 21 × 46 in, a new skylight in asphalt shingles at 6:12, flat ceiling with an attic above, 4 ft straight shaft. Not included: a permit where the framing needs one, wiring to an electric unit, blinds, or repairs to rot found around an old opening.
A leak that turns out to be the roof and not the skylight is on the roof repair page; the glazing numbers that apply to a skylight as to any window are on the window page.
Worth knowing
- The fixed skylight itself is $450 — 22% of the job. The hole is the rest: $253 of flashing, framing and roofing, $468 on the roof, and $861 for the light shaft — 49 sq ft of wall built through 4 ft of attic, insulated, drywalled and painted.
On this page — 5 sections
You pay for the hole
The short version
- A standard fixed skylight, new, over an attic: $2,032. The unit is 22% of it.
- The light shaft is the biggest line after the labour — $861 for 4 ft of attic, $2,088 for 8 ft splayed. A vaulted ceiling has none: $1,351.
- Replacing on the same opening: $1,170. No framing, no shaft.
- A sun tunnel is $965, because it needs neither.
The skylight in the box is $450. What makes it a skylight is a hole in the roof: the sheathing cut, the opening blocked or headed off, a curb if the roof is low, a flashing kit made for that roofing woven into it, 6.5 hours of a roofer on a 6:12 pitch — and then, over a flat ceiling, a tunnel from the roof to the room that has to be framed, insulated like the exterior wall it is, drywalled, taped and painted. That shaft is 49 square feet of wall for a 4 ft attic and more than the skylight cost. Every one of those lines is on this page, and the shaft is the one no quote from memory includes.
$450
The skylight
22% of the job
$253
Flashing, framing, roofing
For this roof
$468
6.5 hours on the roof
Cut, set, flash, patch
$861
The light shaft
49 sq ft of wall
MaterialsEstimator, Skylight and sun tunnel installation price survey · checked 2026-09-23
The shaft is the job
Between a roof and a flat ceiling is an attic, and a skylight has to get its light through it. The shaft is a box of framing from the roof opening to a matching opening in the ceiling, insulated on the outside because the attic is outside, drywalled, taped and painted on the inside because it is the room. Perimeter of the opening times depth is the wall: a standard unit over a 4 ft attic is 49 square feet; over an 8 ft attic, splayed so the ceiling opening is wider than the roof one and the light spreads, it is 136. At about $14 a square foot built, that is where the money goes, and it is also what decides whether the skylight lights the room or a patch of floor under it.
| Over a 4 ft attic | In a vaulted ceiling | |
|---|---|---|
| Standard fixed skylight, new | $2,032 | $1,351 |
| Shaft | 49 sq ft · $681 | None — trimmed opening |
| 8 ft attic, splayed | $3,258 | — |
| Light | A patch, unless splayed | The room |
| Yourself | $1,110, 14.3 h | Half the hours |
VELUX America, Deck-mounted and curb-mounted skylight installation instructions and flashing kits · checked 2026-09-23
The roof decides the rest
Twenty-one inches wide is not an accident: it is what drops between rafters at 24 in centres, so nothing is cut. At 16 in centres, or for a 44 in unit, a rafter comes out and its load is carried on doubled headers to doubled trimmers — 2 hours, the lumber, and usually a permit. Then the roofing: asphalt takes the standard step-flashing kit; standing-seam metal a special kit or a fabricated pan and a roofer who does metal; tile or slate is lifted and cut back around the opening, slowest of all. Under 3:12, and on any membrane roof, the unit sits on a curb 4 in above the surface with the roofing brought up its sides. And above 8:12 the roof is not walked: harness, jacks, staging, and a surcharge on every hour.
| Standard fixed unit, 4 ft attic | New | Replaced | Hours |
|---|---|---|---|
| Asphalt, 6:12, rafters at 24 in | $2,032 | $1,170 | 6.5 |
| Asphalt, 6:12, rafters at 16 in | $2,198 | $1,170 | 8.5 |
| Standing-seam metal, 6:12 | $2,290 | $1,320 | 8 |
| Asphalt, 10:12 | $2,172 | $1,170 | 8.5 |
| Flat membrane, on a curb | $2,384 | $1,340 | 7.5 |
Replaced means a new unit and flashing on the existing opening. The hours are the new one.
International Code Council, International Residential Code, Section R308.6, Skylights and sloped glazing · checked 2026-09-23
Fixed, venting, electric, or a tube
The installation is the same for the three glass kinds; the unit is the difference. Fixed is light. Venting opens on a crank or a pole and lets the hottest air in the house out through its highest window, which is worth more than it sounds in a bathroom or a kitchen. Electric or solar venting opens on a remote and closes on a rain sensor, and is the answer when the skylight is out of reach — the solar version charges itself and needs no wiring. A sun tunnel is a different thing: a dome, a mirrored tube and a diffuser, no framing and no shaft, a morning’s work, and light like a fixture rather than a window.
| Asphalt roof, 4 ft attic | Unit | New, installed | Replaced |
|---|---|---|---|
| Fixed skylight | $450 | $2,032 | $1,170 |
| Venting skylight, manual | $950 | $2,532 | $1,670 |
| Venting skylight, electric or solar | $1,500 | $3,082 | $2,220 |
| Sun tunnel (tubular skylight) | $400 | $965 | $1,005 |
Standard 21 × 46 in units; the tube is a 14 in kit. Two on one visit: $3,891, or $1,946 each.
Before the saw goes in
- The rafter spacing, from the attic, and the depth from roof to ceiling.
- The unit's rough opening against the spacing: 21 in for 24 in centres, or a rafter is cut.
- The flashing kit for this roofing, ordered with the unit, not after.
- Deck or curb: under 3:12 or on a membrane, a curb.
- The shaft on the quote, by the square foot, straight or splayed.
- Where it lands in the ceiling: not on a light, a fan or a wall.
- A dry two days, and the unit on site before the hole.
What goes wrong
01Budgeting the skylight
The unit is 22% of a new installation. The hole, the flashing, the roofer and the shaft are the rest.
Instead — The quote by the line, with the shaft on it.
02A straight shaft down a deep attic
Six feet of straight shaft lights a patch of floor. The room stays dark and the skylight looks like a mistake.
Instead — Splayed: 40% more wall, and it lights the room.
03A unit wider than the rafter bay
A rafter cut without headers is a sagging roof; with them it is a structural job and a permit.
Instead — 21 in units at 24 in centres. Two small ones instead of one large one.
04The wrong flashing kit
A shingle kit on a metal roof, or a deck kit on a curb, leaks in the first storm and looks fine until it does.
Instead — The kit made for this unit on this roofing, ordered together.
05A deck-mounted unit on a low roof
Under 3:12 water sits against it. The code wants 4 in of curb for a reason.
Instead — A curb-mounted unit and a curb kit.
06Replacing the glass on a fogged unit
The fog is a failed seal between the panes; sealed units are not re-glazed.
Instead — A new unit on the same opening — $1,170.
07Blaming the skylight for the roof
A stain below a skylight is often water from uphill that ran down the framing and found the opening.
Instead — The roof above it checked first; the skylight reflashed if it is the skylight.
08Skipping the shaft's insulation
It is an exterior wall in an attic. Uninsulated it sweats in winter and the drywall stains.
Instead — Insulated like the walls, with a vapour retarder facing the room.
- 01Decide what the job isA new opening, a unit replaced on an existing one, or a leak reflashed. The first has framing and a shaft; the other two do not.
- 02Look in the atticRafter spacing — 16 or 24 in — and the depth from the roof to the ceiling below. The depth is the shaft; the spacing says whether a rafter is cut.
- 03Pick the size to the rafters21 in wide drops between rafters at 24 in. Anything wider, or anything at 16 in centres, cuts one and needs headers.
- 04Name the roofing and the pitchAsphalt takes a standard kit; metal and tile take a special one and more hours. Under 3:12 the unit goes on a curb; over 8:12 the hours cost more.
- 05Choose the kindFixed for light, venting for air, electric or solar for a venting one out of reach — and a sun tunnel for a hallway or bathroom that just needs to be lit.
- 06Price the shaft, not just the holePerimeter of the opening times the attic depth is the shaft wall, at about $14 a square foot built. Splayed is 40% more and worth it.
A skylight gets blamed for water that started uphill of it. The roof repair page prices the leak by cause, and says when the flashing around a penetration is the roofer’s job rather than the skylight’s.
If the leak is the roof- Deck-mounted
- A skylight screwed straight to the roof sheathing, with a step-flashing kit woven into the roofing. Lower, cheaper, and allowed from about 14 degrees (3:12) up.
- Curb-mounted
- A skylight that sits on a site-built 2×6 box at least 4 in above the roof. Required under 3:12 and on membrane roofs; usual when replacing an older unit.
- Flashing kit
- The metal pieces, made for the unit and the roofing type, that keep water out around it. Nearly every skylight leak is the flashing, not the glass.
- Light shaft
- The framed, insulated, drywalled tunnel from a roof opening down to a flat ceiling. Straight or splayed. The biggest line on a new skylight over an attic.
- Splayed shaft
- A shaft wider at the ceiling than at the roof, so light spreads into the room. About 40% more wall than a straight one.
- Rough opening
- The framed hole the unit needs. The 21 in wide units are sized to drop between rafters at 24 in centres so nothing is cut.
- Headed off
- A rafter cut for an opening, with doubled headers carrying its load to doubled trimmers either side. Structural, and usually a permit.
- Sun tunnel
- A tubular daylighting device: a dome on the roof, a mirrored tube, a diffuser in the ceiling. No framing, no shaft, no view.
- Venting skylight
- One that opens — by crank, pole, motor or a solar-charged motor — with a rain sensor on the powered ones. The highest window in the house, which is why it moves air.
- Laminated glass
- Two panes bonded to a plastic interlayer; it cracks but stays in the frame. What the code wants over your head, unless it is tempered with a screen below.
- Ice-and-water membrane
- The self-adhering sheet under the flashing and up the sides of the opening. The last defence when the flashing is not enough.
- Steep-pitch surcharge
- What roofers add per hour from about 8:12, when the roof cannot be walked and needs harnesses, jacks and staging.
Common questions
- How much does it cost to install a skylight?
- About $2,032 for a standard 21 × 46 in fixed skylight cut into an asphalt-shingle roof at 6:12 over a 4 ft attic: the unit is $450, and the rest is the roof cut and blocked, a flashing kit, 6.5 hours on the roof and a 49 sq ft light shaft framed, insulated, drywalled and painted. Into a vaulted ceiling, with no shaft, it is $1,351. Venting is $2,532, electric or solar venting $3,082, a sun tunnel $965.
- How much does it cost to replace a skylight?
- About $1,170 for a standard fixed unit on its existing opening: the new unit, a new flashing kit, 3.5 hours to take the old one out and set and flash the new one, and the old one to the dump. None of the framing or the shaft, which is why it is $862 less than a new one. Measure the old unit's rough opening or its curb before ordering: a deck-mounted unit going onto a curb needs the curb version, and a skylight past 20 years is usually replaced when the roof is.
- Why is the skylight itself such a small part of the price?
- Because you are paying for the hole. A $450 unit needs the roof cut open and framed, a flashing kit that fits the roofing, a roofer for 6.5 hours, and — over an attic — a light shaft: 49 sq ft of wall for a 4 ft attic, built like the exterior wall it is and finished like the room. That shaft is $861 on the standard job and $2,088 on an 8 ft attic splayed, more than the skylight above it.
- What does a sun tunnel cost compared with a skylight?
- About $965 installed against $2,032 for a fixed skylight in the same roof. The tube needs no framing — it fits between rafters — and no shaft, because the mirrored tube is the shaft, so it is a 3 hour job. It lights a hallway, a closet or a bathroom like a ceiling fixture; it does not give a view, does not open, and does not warm a room in winter the way glass does.
- How much does it cost to fix a leaking skylight?
- About $510 — 2 hours to lift the roofing, clean, lay new membrane and step flashing and reseal, plus $60 of parts, up to a roofer's minimum. The leak is nearly always the flashing or the seal between the unit and its curb, not the glass. Fog between the panes is a failed seal inside the unit, which is a replacement; and a leak that follows a rain from uphill of the skylight is the roof, not the skylight.
- Does the ceiling change the price?
- More than the skylight does. Over a flat ceiling there is a shaft from the roof to the room: $2,032 for a 4 ft attic, $3,258 for an 8 ft attic with the shaft splayed. In a vaulted or cathedral ceiling the roof is the ceiling, the opening is trimmed, and the same skylight is $1,351.
- Will a rafter have to be cut?
- Not for a 21 in unit at 24 in rafter centres — that is what the width is for. At 16 in centres, or for a 44 in unit at any spacing, a rafter is cut and its load carried on doubled headers to doubled trimmers: 2 hours and the lumber, $2,198 against $2,032, and in most places a permit, because it is structural. A large 44 × 46 in unit is $2,823.
- Does the roof type matter?
- Asphalt shingles take a standard step-flashing kit. Standing-seam metal needs a metal-roof kit or a fabricated pan and a roofer who does metal: $2,290 for the same job. Tile or slate is lifted around the opening and cut back, the slowest of all. A flat or membrane roof, or any pitch under 3:12, puts the unit on a curb: $2,384. And above 8:12 nobody walks the roof, so the hours carry a surcharge — $2,172 at 10:12.
- Fixed, venting or electric?
- Fixed is light: $2,032 installed. Venting opens with a crank or a pole and lets the hottest air in the house out through its highest window: $2,532. Electric or solar venting opens on a remote, closes on a rain sensor, and is the answer when the skylight is out of reach: $3,082, the solar version without wiring. The installation is the same for all three; the unit is the difference.
- Is it cheaper to put in two at once?
- A little: $3,891 for two standard fixed units against $2,032 for one — $1,946 each — because the roof access, the staging and the interior mess are set up once. Two smaller skylights spaced apart light a room more evenly than one large one, and neither cuts a rafter.
- Can I install a skylight myself?
- The materials for the standard job are about $1,110 — the unit, the flashing kit, the lumber, the shaft's framing, insulation and drywall, and a harness — and about 14.3 hours, most of them in the shaft. The hours that matter are the two between cutting the sheathing and having the unit flashed: a hole in a roof does not wait for the weekend. The flashing kit's instructions are the job, and the roofing around it goes back in the order it came out. A sun tunnel is a reasonable first one.
- Does a skylight need a permit?
- Replacing a unit on the same opening usually does not. Cutting a new opening usually does where a rafter is cut and headed off, because that is structural, and some jurisdictions want one for any new roof penetration. The code wants laminated or tempered glass over your head, and a curb under 3:12; the flashing kit takes care of the rest.
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About the author
Pablo Ruiz Quintero — Editor
Editor of MaterialsEstimator. Decides which documents count as a source, what every default value is, and where the line sits between what the reader parses and what the engines compute.
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