Many homeowners use the terms “roof window” and “skylight” interchangeably; however, they are technically two distinct products with different functions and installation requirements.
While both are fantastic ways to bring more natural light into your home, understanding their differences is key to making the right choice for your space.
The debate over roof windows vs. skylights goes beyond just a name.
This post will clarify the key distinctions, helping you decide which option best suits your home’s architecture and your specific needs.
We will cover the core definitions, functional differences, such as operation and access, and the ideal use cases for each.
What is a Skylight?
A skylight is a window installed on a roof with a slope of less than 60 degrees.
Its primary purpose is to let in natural light, especially in areas where a traditional vertical window isn’t feasible, such as hallways, stairwells, or central rooms.
NOTE: Skylights are excellent for illuminating spaces that are far from exterior walls.
There are two main types of skylights:
- Fixed Skylights: These are non-opening units designed purely to bring in light.
- Venting Skylights: These can be opened manually, electrically, or with solar power to provide ventilation, fresh air, and light.
- Because they are often placed high above the floor on ceilings, venting skylights are ideal for out-of-reach applications and can be operated with a remote control.
What is a Roof Window?
A roof window is designed for installation on a roof with a steeper pitch, typically 60 degrees or more.
This steep angle makes it function more like a traditional window on a vertical wall.
The key feature of a roof window is that it’s designed for in-reach applications, such as in a converted loft or attic room.
NOTE: Roof windows are designed for manual operation and are easily accessible.
They open wide, often pivoting from the center or top, which allows them to serve as a means of egress (an escape route in case of a fire) or provide access to the roof.
Roof Window vs Skylight: The 3 Key Differences
To simplify, here’s a quick breakdown of the main differences between the roof window and skylight comparison.
1. Installation Angle & Location
- Skylights: These versatile units can be installed on low-slope or flat roofs (with a pitch of less than 60°).
- They can be curb-mounted (on a raised frame) or deck-mounted (directly onto the roof deck).
- Roof Windows: These are specifically for steep-slope roofs (60° or more).
- They are installed within reach in accessible spaces, such as attics, bedrooms, or living areas.
2. Functionality & Operation
- Skylights: The main function is to provide overhead daylight.
- Venting models open just enough to allow for air circulation.
- They are often automated and can be operated remotely or even powered by solar energy.
- Roof Windows: These are designed for both light and easy access.
- They open wide enough for a person to fit through.
- Roof windows are almost always operated manually.
3. Best Use Case
- Skylights: Ideal for bringing light into dark, central areas of a home where a window can’t be installed, like a windowless bathroom or a long hallway.
- Roof Windows: Perfect for habitable spaces like loft or attic conversions, where you need a functional window for fresh air, an escape route, and a view.
Which One Should You Choose?
Making the right choice in the roof window vs skylight debate depends on your specific goals and your home’s structure.
If you simply want to add natural light to a dark hallway and have a roof with a low pitch, a skylight is your best bet.
If you are converting an attic into a bedroom and need a window that opens easily for ventilation and to meet fire escape safety codes, a roof window is the ideal choice.
NOTE: Choosing the right option also depends on your roof’s structure and local building codes.
A trusted expert, such as the team at Saratoga Roofing, can assess your home and provide a recommendation that fits your needs and budget, whether it requires a skylight installation or repair.
FAQs about Roof Windows and Skylights
Can I install a roof window on a flat roof?
No, a roof window is not suitable for a flat or low-slope roof.
They are specifically designed for steep pitches (60 degrees or more) to ensure proper water drainage and functionality.
For flat roofs, a curb-mounted skylight is the appropriate choice.
Is a skylight or a roof window better for ventilation?
Both venting skylights and roof windows provide ventilation, but a roof window is generally more effective at creating significant airflow.
Because it opens much wider and is within reach, it can be used to quickly air out a room, similar to a standard vertical window.
Can a skylight be used as a fire escape?
Typically, no.
Most venting skylights open only a few inches, which is not enough for a person to pass through.
A roof window, however, is often designed to meet egress requirements, making it a valid fire escape route in a habitable attic space.
Which is more expensive, a roof window or a skylight?
Costs can vary widely based on size, features (fixed vs. venting, manual vs. solar-powered), and installation complexity.
Generally, a basic fixed skylight might be less expensive than a fully operational roof window.
However, a high-end, solar-powered venting skylight with a rain sensor can be more expensive.
Do roof windows and skylights leak?
Modern roof windows and skylights are designed with advanced flashing kits and seals to ensure complete watertightness when installed correctly.
Leaks are almost always the result of improper installation or damage to the flashing or seal over time, not a flaw in the product itself.
This is why professional installation is crucial.
Do I need planning permission to install a roof window or skylight?
In many cases, installing a roof window or skylight falls under permitted development, meaning you don’t need planning permission, especially if it doesn’t project significantly from the existing roof plane.
However, rules can vary, so it’s always best to check with your local planning authority.
Which option offers better insulation?
Both modern skylights and roof windows come with energy-efficient double or triple-glazing options, Low-E coatings, and argon gas fills to provide excellent insulation.
The performance is comparable, so the choice should be based on function rather than a significant difference in energy efficiency.
Can I install a skylight myself?
While it is possible for an experienced DIYer to install a skylight, it is a complex job that involves cutting a hole in your roof.
Any mistake can lead to serious leaks and structural damage.
Hiring a professional roofing contractor, such as Saratoga Roofing, ensures that the installation is done correctly and is fully warrantied against leaks.
How are roof windows operated?
Roof windows are typically operated manually.
They have a handle at the top or bottom of the frame that allows you to pivot the window open to various degrees for ventilation or fully for cleaning and egress.
Can blinds be fitted to both roof windows and skylights?
Yes, blinds are available for both.
Because roof windows are standardized for habitable spaces, they have a wide range of compatible, manually operated blinds.
Skylights also offer a variety of blind options, including solar-powered and remote-controlled versions, which are ideal for out-of-reach installations.
Ready to Add More Light?
The choice between a roof window vs skylight ultimately depends on your roof’s pitch, whether the space is within reach, and what you need the window to do—provide light, or provide light and access.
Both are excellent investments that can dramatically improve your home’s ambiance and value by flooding it with natural light.
Ready to brighten your home?
Contact a professional roofer to discuss which option is best suited for your space and obtain a quote.