Bedrooms and kids’ rooms: Consider a double window with e.g. 2 x MK08 windows (2x78 cm x 140 cm) installed right next to each other. This option creates a light airy atmosphere and an amazing connection to nature outside. Plus, smaller rooms will feel an added spaciousness
Roof window sizes
Did you know that daylight is more powerful from above, and that roof windows can provide 2 to 3 times more daylight than facade windows? If you want to reap all the benefits of bringing more natural light into your home with a roof window, it’s important to pick a size that’s tailored to the room’s size, layout, and purpose.
At VELUX, we offer a wide range of roof window sizes to suit all kinds of projects, whether you’re giving a tired loft a fresh new feel, adding light to a modern extension, or just making a small bathroom feel that little bit brighter.
VELUX roof windows don’t just open up your space; they open up new ways to enjoy it. From big, open-plan living areas to compact rooms that need a lift, there’s a size that fits. Not sure what you need yet? Let’s take a closer look at how to find the right size for your home.
Understanding VELUX roof window sizes
VELUX makes it simple to choose the right window for your project. Our roof windows come in a range of carefully considered sizes, with coded labels to help you easily identify them. These codes tell you exactly what size the window is, meaning you can pick new windows with confidence or find a perfect replacement for an older VELUX model.
Here’s a quick guide to some of our sizes:
Size code and window size (width x height)
- FK06 - 66 cm x 118 cm
- MK04 - 78 cm x 98 cm
- MK06 - 78 cm x 118 cm
- MK08 - 78 cm x 140 cm
- PK06 - 94 cm x 118 cm
- PK08 - 94 cm x 140 cm
- SK06 - 114 cm x 118 cm
- SK08 - 114 cm x 140 cm
- UK04 - 134 cm x 98 cm
- UK08 - 134 cm x 140 cm
These sizes cover everything from compact spaces needing a little more light to larger rooms that benefit from floor-to-ceiling glazing and dramatic views of the outdoors. Often windows are combined into a double installation, to ensure an optimal daylight influx and a great view and connection to the outdoors.
(Note: This is a selection of some of our window roof sizes – more options are available)
How to find the size of your existing VELUX window
If you already have a VELUX roof window and you're looking to replace it or match it, you’re in luck – it’s really easy to find your current window size.
Simply open your window and look for the metal type sign on the top sash. This plate shows the VELUX window code (like MK06 or PK08), which tells you the exact size and model. This makes replacing or upgrading your existing window a straightforward process without any guesswork and means you can shop with confidence knowing you’re getting the right fit.
Get the size of your roof window right, and you’ll notice the difference
The size of your roof window plays a big part in how a room feels. Too small, and you might still find yourself switching the lights on. But get it right, and you’ll bring in just the right amount of daylight to make the space feel bigger, more open, comfortable, and a joy to spend time in.
In fact, 27% of homeowners* would have preferred a bigger roof window than the one they installed. And there are many good reasons for that. By inviting more natural light into the room, you can do great things for your general mood, as exposure to natural sunlight helps regular the body’s internal clock.
It’s not only about light, either, but also about the opportunity to open the room up to your outdoor space and the nature surrounding it. Furthermore, the right size window can help regulate temperature, reduce the need for artificial lighting, and make your home feel fresher and more energy-efficient overall.
*VELUX Combi Solution Study by NEPA, Dec 2019-Jan 2020.
General roof window size recommendations
As a general guide, the window size should be around 15-20% of your room’s floor space if you have a pitched roof, while the recommended size for flat roofs generally should be around 10-15%.
If you already know that the roof window will be subject to shadows and obstruction from outside elements, such as neighboring buildings, a 25-30% roof window to floor ratio would be a good idea.
It’s a simple rule of thumb, but it really helps when you want a room that looks good and feels even better. If you’re uncertain about what roof window size to go for, ask VELUX Advisory Service for a daylight analysis of your room.
Choosing the size a new window for your room
Every room is different, and so are your needs. The ideal roof window size is overall a combination of multiple factors like room type, room size, and roof construction - A general rule of thumb is also that the glazed area should be around 20% of the room. Here’s a little advice to help you pick the perfect size:
Small room
Small rooms, such as stairwells, or utility rooms, often only need a single window for fresh air and functional daylight.
Medium-sized room
Medium-sized rooms, such as bedrooms and kids’ rooms, are ideal for a double window installation to allow more daylight inside and deliver added spaciousness to the room. Furthermore, a double window installation can bring more focus to the view outside and make the room feel more connected to nature outside.
Large room
Large rooms, such as open-plan living spaces, lofts or open-floor kitchens, can benefit from larger window combinations to maximise access to natural daylight, create spaciousness, and achieve a closer connection to the outside. Plus, larger window combinations are an excellent way to add wow factor to the room.
Bathroom
For bathrooms, you can go for either a smaller or bit larger roof window solution, depending on preferences. A compact window lets you maintain privacy while still being able to enjoy the benefits of natural light and ventilation. If privacy is less of a concern, you can also add a large roof window or window combination to make the space feel brighter and more connected to nature.
Remember, you can always combine several windows for even greater impact. Our Duo and Triple roof window combinations, for example, pair or triple up windows for more light, better views, and a modern architectural finish.
What if my roof is at a low pitch?
Not all roofs are the same. If your roof has a shallow pitch—between 10° and 20°—you’ll need a special low-pitch roof window. VELUX offers specially designed low-pitch roof window models to maintain excellent insulation, drainage, daylight intake, and add fresh air to your house extension, even when the roof angle is flatter than usual.
Luckily, you can choose from dedicated VELUX low-pitch solutions to enjoy all the benefits of natural daylight and ventilation without compromise.
Roof window sizes, endless flexibility
While our roof window sizes cover most homes and projects, there’s always room to get creative. You can:
- Combine multiple roof windows for a larger glass area and a panoramic view
- Add fixed elements below your opening window for a stunning floor-to-ceiling effect
- Choose between manual roof windows and VELUX electric or solar-powered windows
- Combine your roof windows with interior blinds for light control or privacy. For heat protection, choose our exterior awning blinds or shutters. If you want even more convenience and comfort, include our smart controls such as the VELUX App.
The possibilities are endless. Whether you’re planning a single window or a dramatic feature wall of glazing, VELUX has the sizes and styles you need to bring your vision to life.
Tailored solutions for every room
Every room in your home can benefit from the right window size:
Bathrooms: A single roof window can bring in increased natural light and control ventilation while maintaining privacy. For tranquility, go with a larger single window or duo combination to bring nature in. You can also add a moisture-resistant blind for extra privacy. As the bathroom is known for being a room with high humidity levels, it’s key to choose a VELUX roof window with a maintenance-free finish.
Living rooms: Go big! Combine a couple of PK08 (94 cm x 140 cm) or UK08 (134 cm x 140 cm) windows. Alternatively, go for our trio or quattro window combinations for a light-filled place with daylight, connection to the outside, and wow-factor.
Kitchens: A double or triple window combination above your worktops lets in both daylight and ventilation, making the space feel fresh and inviting. As kitchens often can become rather humid when you cook, a roof window with a maintenance-free finish is a must-have.
Home offices: A double window will make the room feel spacious and bring daylight right where you need it to help boost focus and productivity. For optimal indoor comfort and working conditions add an awning blind to maintain a comfortable room temperature or translucent blind for a flexible light dimming solution
Quick guide: How to choose your VELUX window size
- Measure your room: Aim for a window solution corresponding to 15-20% of your floor area.
- Think about usage: Go for bigger windows or window combinations for primary rooms like bedrooms, kids' rooms or living rooms where you spend important time. For less used, smaller rooms, a more compact option is often more popular.
- Consider your roof type: Normal or low pitch? We have solutions for both.
- Consider the ways of operating the windows: Choose between VELUX electric and solar-powered options for extra comfort and convenience or manual windows. You can supplement your electric roof window with our VELUX App control, for full smart home control of your VELUX electric roof windows.
To further enhance the control of your indoor climate, you can combine your roof windows with interior blinds for light control, and exterior awning blinds or shutters for heat protection.
Ready to find the right fit for your home?
At VELUX, we believe that more daylight, more fresh air, and better living starts with the right roof window – and that all begins with finding the right size.
Whether you're replacing an old window or starting a brand-new project, our roof window sizes give you the flexibility and choice to create the home you've always dreamed of.
Explore the full range of VELUX windows and discover just how easy it is to transform your space. Need a little help? Contact our team for expert advice, or check out our Design Advisory service to get personalised recommendations for your project.