
A skylight is a window installed on the roof or ceiling. It can bring a slice of the outdoors inside your home and brighten up your mood (and your life) in more ways than one.
To further understand what a skylight is, you must know its purposes and the different parts that make up a typical skylight.
Parts of a Skylight

A skylight has several parts that provide natural light, ventilation, and weather protection. Here are the main parts of a typical skylight:
- Glazing: This transparent or translucent component allows natural light to pass through. It can be made of different materials, such as tempered glass or acrylic plastic. Depending on the type of glazing used, it can offer insulation and protection from UV rays.
- Skylight frame: Typically made of vinyl, metal, or wood, the frame of a skylight provides structural support and holds the glazing in place. The frame must be secured properly to ensure your skylight can withstand harsh weather conditions.
- Flashing: It’s a crucial component, as it creates a weather-resistant barrier around the skylight to help prevent leaks. Usually made of metal, flashing is installed over the joints between the skylight and the roof.
- Jamb: Similar to doors, skylights also need a jamb. Apart from creating a sealed connection between the roof and the skylight, a jamb also helps provide more structural support.
- Head: It’s the top horizontal part of the skylight. Designed to support the glazing or glass, the head also can help protect against water ingress.
- Skylight sash: You’ll mostly find this movable frame in vented skylights. It holds the glazing in place and allows the skylight to open and close.
- Sill: Found at the bottom part of the skylight, the sill helps prevent pooling near the frame. It’s often sloped to help drain water away from the skylight.
Depending on the type and design of the skylight, there may be additional parts. For example, you might need to apply a gasket or sealant between the skylight and the roof to prevent water from seeping into the room. For vented skylights, a motor is also installed to allow the skylight to open and close for ventilation.
Main Purposes of a Skylight
Most homeowners install skylights for the following primary reasons:
1. Bring in Natural Light
Unlike traditional windows installed on side walls, skylights are roof windows that let in natural light from above. Because of its position, a skylight can bring in more sunlight than an average window – illuminating a room more effectively and making it feel more spacious.
My Tip: A fixed skylight is ideal for letting natural light into large spaces like living rooms and dining areas. For small or narrow spaces like hallways and powder rooms where a large skylight can’t fit, it’s best to install a tubular skylight.
2. Lower Heating Costs
Skylights are energy efficient since there’s less need for artificial lighting. But did you know that they also can help lower your heating costs? With the right glazing material, a skylight can help regulate indoor temperatures and lessen heat loss in the winter.
Expert Tip: Alexandra Rempel, a building scientist at the University of Oregon College of Arts and Sciences, suggests adding sliding insulation panels to help keep the heat in the room at night. According to her, doing so can help reduce heating bills by up to 80%.
3. Regulate Airflow (for Vented Skylights)

Apart from letting in natural light, a vented skylight can open and close to help improve the ventilation and air quality in the room. This type of skylight can make a room cooler and more comfortable by pushing the warm, stale air out and letting fresh, cool air in. With such a skylight, you can lower your cooling costs.
My Tip: You can install a vented skylight in rooms where humidity or stale odors tend to linger, such as kitchens and bathrooms.
Note: Even in regions where it’s cloudy most of the time, skylights can still have a purpose. Apart from vented skylights that can help improve a room’s ventilation, other types also can give a fresh vibe and add to the aesthetic appeal of a home. Plus, they’re perfect for stargazing at night.
FAQ About Skylights
Can I Add a Skylight on an Existing Roof?
Yes, but it can be challenging compared to installing a skylight on a new roof. You’ll need to hire a roofing contractor for the job. Plus, you must first assess the current condition of your roof if it can support the skylight.
How Much Does a Skylight Cost?
A skylight costs around $2,115, on average. But the actual cost will depend on the type of skylight installed and other cost factors.
Is a Skylight Hard to Maintain?
Depending on where you live, skylights are generally easy to maintain. The most important thing is to inspect and clean your skylight once or twice a year. If water is seeping into the room, you must fix the leaking skylight immediately. It’s the same with other damages like cracks and hail damage — have them repaired right away to avoid further damage.
Is a Skylight Right For You?
Installing a skylight is a pretty huge home improvement project – it’s not something you can easily remove if you suddenly realize it’s not suitable for your home. But now that you know what a skylight is made of and what its purposes are, you can contact a professional to decide whether this roof addition would add value to your home.
Note: Home Gnome may get a referral fee for matching you with pros in your area.
Main Photo Credit: alexandre zveiger / Adobe Stock Free / License