iWindow & Vitria flat roof windows
The new standard in flat glass. Our flat roof windows combine the highest thermal performance with a refined design that blends seamlessly into modern architecture. Available in more than 80 sizes and always in stock for every new-build or renovation project.
iWindow
Extra-insulating flat roof window
Our iWindow range stands for uncompromising quality. With a sleek, compact PVC frame and super-insulating safety glass, you achieve Ug values of up to 0.5 W/m²K. The result: a timeless design that meets the strictest passive house requirements.
Vitria
Budget-friendly flat roof window
Vitria proves that premium design can be accessible. This flat roof window with double HR++ glazing offers excellent insulation up to 1.1 W/m²K and a modern flush design for flawless water drainage. The ideal step from a plastic skylight to the luxury of glass.
Adapter frame
Replace your old skylight without demolition work
Upgrade your roof in less than a day. With our universal adapter frame, you can install a modern flat roof window directly on your existing curb. Without touching the roof covering, you immediately benefit from better insulation and a sleeker look.
Why glass
Why choose glass?
Flat glass is the ultimate aesthetic upgrade for your flat roof. In addition to unmatched transparency, it offers superior thermal and acoustic insulation. Thanks to innovative coatings, you enjoy maximum light without your home overheating.
Dealer
Find a Skylux dealer in your area
Your project deserves the best guidance. From our Belgian family business, we work with a network of experts who advise you on the right choice and ensure flawless installation. That way, you are assured of years of carefree daylight.
The iWindow collection
Our iWindow range stands for uncompromising quality. With a sleek, compact PVC frame and super-insulating safety glass, you achieve Ug values of up to 0.5 W/m²K. The result: a timeless design that meets the strictest passive house requirements.
The Vitria collection
Vitria proves that premium design can be accessible. This flat roof window with double HR++ glazing offers excellent insulation and a modern flush design for flawless water drainage. The ideal step from a plastic skylight to the luxury of glass.
Technology meets uncompromising design.
Choosing a Skylux flat roof window means choosing the future. From superior insulation values to an elegant finish worth showing. Every detail is designed to transform your living comfort.
More than just glass.
Create the perfect light incidence. Personalise your iWindow with the right finish. Choose opal glass for soft, diffused light and complete privacy. Or opt for solar control glass to keep your home cool during hot summer days, without losing natural light.
A glass upgrade. Plug & Play.
Replace your old plastic skylight with the latest glass technology. Thanks to the Skylux adapter frame, you can transform your roof without touching the existing roofing. Faster, more durable and immediate results.
Complete your living comfort.
Expand your iWindow with smart accessories. From sunblinds to DuoControl smartphone control – everything for the ultimate living experience under a flat roof.
Compare the models: iWindow2, iWindow3 & Vitria
The right choice depends on your ambitions in terms of insulation and budget. From the unmatched Ug value of 0.5 in iWindow3 to the flawless flush design of Vitria. Choose based on performance.
iWindow3
Maximum efficiency for passive houses.
iWindow2
The modern standard for every flat roof.
Vitria
Accessible design without compromise.
Insulation (Ug)
0.5 W/m²K
Insulation (Ug)
1.0 W/m²K
Insulation (Ug)
1.1 W/m²K
Glazing
HR+++ Triple glazing
Glazing
HR++ Double glazing
Glazing
HR++ Double glazing
Sound (Rw)
41 dB
Sound (Rw)
39 dB
Sound (Rw)
39 dB
Design
Flush glass, designer look with black edge
Design
Flush glass, designer look with black edge
Design
Flush glass
Glass options
Clear, opal and solar control
Glass options
Clear, opal and solar control
Glass options
Clear only
Technical documentation.
Everything for professionals and DIYers. Download installation instructions, technical drawings and declarations of performance for iWindow and Vitria.
Frequently asked questions about flat roof windows
What is a flat roof window?
A flat roof window is a modern roof window made of flat glass, specially designed for flat roofs. Unlike a skylight, it offers crystal-clear views, superior insulation values and a minimalist look that blends seamlessly into your interior.
What are the benefits of a flat roof window?
Flat roof windows offer maximum daylight, excellent thermal insulation (Ug up to 0.5) and high acoustic insulation against rain and ambient noise. They also increase the value of your home thanks to their sleek, modern design.
What are the disadvantages of a flat roof window?
Because of the flat glass pane, dirt is visible more quickly than on a spherical skylight. Skylux solves this with the 'flush design': the glass pane sits slightly higher than the window frame, ensuring natural water drainage and a self-cleaning effect with every rain shower.
What are the insulation values of a flat roof window?
Our flat roof windows are among the best on the market. The iWindow2 offers HR++ double glazing with an insulation value of 1.0 W/m²K, while the iWindow3 with HR+++ triple glazing reaches a passive value of 0.5 W/m²K.
What is the acoustic insulation of a flat roof window?
Thanks to the mass of laminated safety glass, the sound of rain and hail is kept to a minimum. With sound insulation (Rw) up to 41 dB, you enjoy complete peace and quiet, even during a heavy thunderstorm.
What does a flat roof window cost?
The price depends on the size, the type of glass and the operation. The Vitria series offers an excellent entry price for those who want to switch from a skylight to glass, while the iWindow series is the ultimate investment in luxury and energy savings.
What is the best flat roof window?
That depends on your needs. For maximum insulation and passive building, iWindow3 is the best choice. For those looking for sleek design at a competitive price, Vitria is an excellent alternative. Both models offer the Belgian quality Skylux is known for.
How do I install a flat roof window?
Our windows are delivered ready to install and often pre-assembled on the curb. Thanks to an intelligent clip system, installation is quick and error-free. We always recommend a roof pitch of at least 5° for optimal water drainage and self-cleaning.
How do I measure a flat roof window?
At Skylux, we always work with the 'daylight size'. This is the size of the opening in the roof (inside of the curb). Measure the length and width of this opening to determine the correct order size for your window and curb.
Can I replace my old plastic skylight with a flat roof window?
Yes, with our adapter frame, virtually any existing skylight on a wooden, PVC or concrete curb can be replaced with glass. Without damaging the roof covering, you can transform your old skylight into a modern glass roof window.
Where can I view Skylux flat roof windows?
You can discover our products in the showrooms of our official distributors across Belgium. Easily find a Skylux expert near you via our online distributor locator for professional advice tailored to your needs.