What’s the Difference Between Skylights, Roof Windows, and Rooflights?
When it comes to bringing more natural light into your home, terms like skylight, roof window, and rooflight are often used interchangeably. However, they’re not quite the same. Each option is designed for different roof types, installation methods, and ventilation needs. Understanding the differences can help you choose the right solution for your space, whether you’re planning a loft conversion, extension, or flat-roof renovation.
Table of Contents
Skylights, Roof Windows, Rooflights: What’s the Difference?
Let’s clarify the terminology upfront:
| Feature | Skylight | Roof Window | Rooflight |
|---|---|---|---|
| Definition | A general term for any glazed panel set into a roof | A glazed unit installed in line with the roof pitch, often opening | Any flat roof glazing unit (usually fixed) |
| Roof Type | Pitched or flat | Pitched roofs only | Flat roofs (or low pitch) |
| Ventilation | Optional (some open) | Typically opening | Usually fixed |
| Planning Classification | May require building control | Regulated under Part B, L | Subject to Part L for U-values |
| Installation | Often installed above the upstand | Installed like a roof tile | Sits on a kerb/upstand |
How to Choose the Right Option for Your Roof Type
✅ Best for Flat Roofs
Choose a rooflight — ideally frameless and fixed
Sits on a kerb or upstand (typically 150mm)
Looks sleek from below with edge-to-edge glass
Recommended: Frameless fixed rooflights from Skylights.co.uk for kitchens, bathrooms, and extensions.
✅ Best for Pitched Roofs
Aligns with tiles/slates and opens for ventilation
Suitable for lofts, bedrooms, and egress compliance
You can also choose frameless fixed non-opening roof windows for a seamless appearance
✅ Best for Compact or Narrow Spaces
Choose modular skylights in a grid pattern
Works well in side-return extensions or stairwells
Frameless vs Framed Skylights: What’s the Difference?
| Feature | Frameless Rooflights (Skylights.co.uk by KingsView Glass) | Framed Roof Windows |
| Design | Sleek, minimal, no visible internal frame | Classic, visible frame inside |
| Roof Type Compatibility | Best for flat or low-pitch roofs | Best for pitched roofs |
| Glazing Area | Larger visible glass | Slightly reduced |
| Ventilation | Fixed (add extractor if needed) | Often openable |
| U-Value | As low as 0.9 W/m²K with triple glazing | Typically 1.1–1.4 W/m²K |
FAQs: Skylight, Roof Window, and Rooflight Explained
A skylight is a general term. A rooflight usually refers to a flat roof unit, while roof windows refer to pitched roof installations.
Choose a roof window that opens and meets egress rules. Brands like Roto Roof Windows specialize in these.
A frameless, fixed rooflight from Skylights.co.uk gives maximum light with minimal framing.
Not always. If they don’t project more than 150mm from the roof surface, they may be allowed under permitted development.
Real Homeowner Testimonials
"We installed a 2m x 1.5m frameless rooflight from Skylights.co.uk above our island. It floods the room with daylight and looks absolutely stunning."
— Anna, homeowner in Nottingham
"Our loft needed fire escape windows, so we went with pitched roof windows. The difference in ventilation and compliance was key."
— Simon and Emily, Reading
Expert Advice from the Field
“In my experience installing both roof windows and rooflights, the key is choosing the right product for the pitch and usage. Frameless designs are unbeatable for clean interiors and flat roofs.”
— Graham Ellis, Roof Glazing Specialist, South London
“Frameless fixed rooflights are one of the biggest trends in 2025. They’re ideal for flat roof extensions — and the energy savings with triple glazing are real.”
— Amira Patel, Residential Architect
Final Takeaways
✅ Skylight is a broad term — understand when to use rooflights (flat roofs) or roof windows (pitched roofs)
✅ Choose frameless rooflights from Skylights.co.uk by KingsView Glass for modern, flat roof applications
✅ Consider building regs and ventilation when choosing the right product
✅ You can also install frameless fixed roof windows in pitched roofs for a minimalist finish
✅ Use expert support and videos to guide installation and compliance
