The main types of skylights split along three separate questions people tend to blur together: how the unit operates, how it attaches to the roof, and what the glazing is made of. Sort those out and the choice gets simple. By The Roofing Brief Team. Last reviewed August 2026.
What are the main types of skylights?
By operation, skylights fall into four categories: fixed (sealed, never opens), vented or ventilating (opens for airflow), tubular (a small dome and reflective tube that pipes daylight into tight spaces), and custom or specialty units (domes, pyramids, and walk-on glass). Homeowners usually pick the operation type first, then decide on mounting and glazing.
Two other choices sit underneath that operation type and drive both price and leak risk: the mounting method (curb-mounted versus deck-mounted) and the glazing material (glass, acrylic, or polycarbonate). Most competing guides treat mounting as if it were a separate “type” of skylight. It is not. A fixed skylight can be curb-mounted or deck-mounted, and so can a vented one.
Types of skylights compared
This table compares the four operational types on how they work, a typical installed cost band, what each suits, and relative leak risk. Costs vary widely by size, roof pitch, glazing, and local labor, so treat these as planning ranges rather than quotes. For itemized pricing, see our skylight installation cost breakdown.
| Type | How it works | Typical installed cost | Best for | Relative leak risk |
|---|---|---|---|---|
| Fixed | Sealed glazing that never opens; light only | About $1,000 to $2,500 | Stairwells, hallways, high ceilings, attics | Lowest (no moving parts or seals) |
| Vented (ventilating) | Opens by hand crank, motor, or solar actuator for airflow | About $1,500 to $3,500+ | Kitchens and bathrooms that need moisture and heat release | Moderate (hinge, seal, and flashing wear) |
| Tubular (sun tunnel) | Roof dome feeds a reflective tube to a ceiling diffuser | About $500 to $1,500 | Closets, small baths, hallways with no attic-to-ceiling line of sight | Low (small penetration, factory flashing kit) |
| Custom / specialty | Domes, pyramids, ridge glazing, or structural walk-on glass | $2,500 to $10,000+ | Architectural features, flat roofs, roof decks | Varies (large penetrations raise risk) |
Fixed skylights
A fixed skylight is a sealed glazed unit that does not open. It is the simplest and most common type, with no hinge, motor, or weatherstripping to fail, which is why it carries the lowest leak risk of any operable option. Fixed units suit spaces you want brighter but do not need to ventilate, such as stairwells, hallways, vaulted living rooms, and attic conversions.
Because there are no moving parts, fixed skylights cost less to buy and install than vented models of the same size, often landing near the bottom of the price bands above. The trade-off is zero airflow: a fixed unit over a bathroom or kitchen does nothing for steam or cooking moisture, which can drive condensation on the glass in cold weather.
Vented (ventilating) skylights
A vented skylight opens to let warm, humid air escape, which makes it the go-to type for kitchens, bathrooms, and any room prone to moisture buildup. Opening the unit uses the stack effect: hot air rises and exits through the roof while cooler air is drawn in from lower windows. Vented models cost more than fixed ones because of the operable sash, seals, and hardware.
Vented skylights are sometimes called roof windows, though the two terms are not identical. We break down the distinction in our guide on skylight vs roof window. In short, a true roof window is designed for occupied attic rooms and rotates far enough to double as an emergency egress, while most ventilating skylights open only a few inches.
Manual, electric, and solar venting
Vented skylights differ by how they open, and the mechanism changes both convenience and price:
- Manual: a hand crank or a control rod for out-of-reach units. Lowest cost, but you have to remember to close it before rain.
- Electric: a wired or remote-controlled motor, often paired with a rain sensor that closes the unit automatically when it detects moisture.
- Solar-powered: a rooftop panel runs the motor and charges a battery, so no wiring is needed. Historically these qualified for a federal tax credit; that treatment has changed, and we cover the current reality in our solar skylight guide.
Tubular skylights (sun tunnels)
A tubular skylight, also called a sun tunnel, uses a small roof-mounted dome that channels daylight down a mirror-finished tube to a diffuser lens on the ceiling below. It is the most economical way to add daylight, typically installed for a few hundred to about $1,500, and its small penetration makes it one of the lower-risk options for leaks. Common tube diameters are 10, 14, and 21 inches.
Tubular units shine in spaces a conventional skylight cannot reach: interior closets, small bathrooms, laundry rooms, and hallways where the ceiling sits below other floors or framing blocks a straight shaft. Flexible tubing can route around obstructions, though every bend costs some brightness. Add-ons include a dimmer, a night-light kit, and an integrated exhaust fan on some models.
Custom and specialty skylights
Custom and specialty skylights cover everything beyond a standard rectangle: domed and pyramid units for flat roofs, ridge and barrel-vault glazing that runs along a roof peak, and structural walk-on glass for roof decks and floors. These are made to order, so pricing runs from about $2,500 into five figures depending on size, structural glass, and framing.
Dome and pyramid shapes shed water and debris well, which is why they are common on low-slope and flat roofs where a flat pane would pond. Large custom penetrations raise the stakes on flashing and structural framing, so they belong with an experienced installer. If your roof is flat or low-slope, start with our dedicated guide to flat roof skylights, which covers the curb and code details that matter most there.
Curb-mounted vs deck-mounted: the mounting question
Mounting is a separate decision from operation type, and it drives both cost and leak performance. A curb-mounted skylight sits on a raised wooden frame (the curb) built above the roof deck; a deck-mounted skylight attaches directly to the deck and sits lower and flatter against the roofline. Any operation type can use either mount, though tubular units and most flat-roof units are curb-mounted.
- Curb-mounted: the unit itself is often cheaper (roughly $150 to $1,500 for the skylight), and the raised curb helps drainage, which is why it is standard on flat and low-slope roofs. The curb adds a step to installation.
- Deck-mounted: sits flush for a sleeker look and integrated factory flashing, usually a cleaner long-term seal on pitched roofs. Unit and install costs typically run higher, often in the $1,500 to $2,500 range before extras.
Whichever mount you choose, flashing quality decides whether the unit stays dry. Most skylight leaks trace back to failed or improvised flashing rather than the glass itself, a pattern we detail in our skylight leak repair guide.
Glazing: glass, acrylic, and polycarbonate
Glazing is the see-through material, and it affects clarity, durability, and price independent of the skylight type. Tempered or laminated glass is the standard on quality units: it stays clear for decades, resists scratching, and laminated glass holds together if it breaks. Acrylic and polycarbonate plastics cost less and resist impact but can scratch, yellow, or haze over the years.
Beyond the material, count the glazing layers. Single-pane units are cheap and largely obsolete for conditioned spaces; double-glazed (insulated) glass is the norm; triple-glazing and low-emissivity (low-E) coatings cut heat gain and loss further. For rooms that overheat or lose warmth through the roof, an insulated low-E unit is worth the premium; see our overview of energy efficient skylights for glazing and rating specifics.
How to choose the right type of skylight
Match the type to the room and roof in this order, and the rest of the spec follows:
- Does the room need airflow? Yes points to a vented unit; light-only points to fixed or tubular.
- Is there a straight line from roof to ceiling? No, or a very small space, favors a tubular sun tunnel.
- What is the roof slope? Flat or low-slope leans curb-mounted, often a dome or custom unit; pitched roofs suit deck-mounted for a flush seal.
- How much sun does the room already get? South- and west-facing rooms benefit most from low-E insulated glazing to control heat.
- What is the budget and who installs it? Compare quotes and models before buying; our roundup of the best skylight brands and the VELUX skylight lineup shows how features map to price.
Frequently asked questions
What are the three main types of skylights?
The three most commonly cited types are fixed, vented (ventilating), and tubular. Fixed skylights are sealed and provide light only, vented skylights open for airflow, and tubular skylights pipe daylight through a reflective tube into small or enclosed rooms. Custom and specialty units, such as domes and pyramids, form a fourth category for flat roofs and architectural features.
What is the difference between fixed and vented skylights?
A fixed skylight is permanently sealed and never opens, so it adds light but no ventilation and carries the lowest leak risk. A vented skylight opens by crank, motor, or solar actuator to release heat and humidity, which suits kitchens and bathrooms. Vented units cost more because of the operable sash, seals, and hardware.
Which type of skylight is least likely to leak?
Fixed skylights leak the least because they have no hinge, seal, or motor to wear out, followed closely by tubular units with their small factory-flashed penetration. Across all types, most leaks come from failed or improvised flashing rather than the glazing, so correct flashing and a low-slope-appropriate curb matter more than the type alone.
Are tubular skylights worth it?
Tubular skylights are worth it for small or enclosed rooms with no straight path for a conventional shaft, such as closets, interior bathrooms, and hallways. They are the cheapest daylighting option, typically a few hundred to about $1,500 installed, and low-risk for leaks. They deliver less light than a full skylight and do not provide a view of the sky.
What is the difference between curb-mounted and deck-mounted skylights?
A curb-mounted skylight sits on a raised wooden frame above the roof deck and is standard on flat and low-slope roofs; the unit itself is often cheaper. A deck-mounted skylight attaches directly to the deck, sits flush for a sleeker look with integrated flashing, and usually costs more but seals cleanly on pitched roofs. Mounting is separate from whether the unit is fixed or vented.
What glazing is best for a skylight?
Tempered or laminated insulated glass with a low-emissivity coating is the best all-round glazing: it stays clear for decades, resists scratching, and controls heat gain and loss. Acrylic and polycarbonate cost less and resist impact but can scratch or yellow over time. Double-glazing is the practical minimum for conditioned rooms; triple-glazing suits severe climates.