Roof window sizes and dimensions

What roof window size do I need?

The size of your roof window makes an enormous difference to the amount of light that enters your room and is critical to the sense of space.

In general, we recommend that the size of your roof window should be at least 20% of your room’s floor area.

A rooflight lets in up to twice as much daylight as a façade window of the same size.

If you have difficulty finding the right size to suit your needs, or if you need a different size than the preset, VELUX Design Advisors can guide you and help you find a suitable solution before you finalise your order.

How do I see what window size I have?

Are you already lucky enough to have a VELUX roof window in your home and need to find its type or size? Then all you need to do is find the reference of your VELUX roof window using the identity plate specific to each window.

Every VELUX roof window produced after 1968 have a type sign that provides accurate information about the window. The type sign is located in the right corner of the top sash behind the ventilation flap.

Here you will find old codes for existing windows. You can see the type, size, variant and production code.

This will help you when replacing old windows or undertaking house renovation projects.

Bring the magic of light into your home

Are you starting a home renovation project? Maybe you’re looking for ideas to bring more daylight into your space, refresh your indoor climate and become less reliant on artificial lighting?

Installing a roof window will transform your room and your home. Your living space will be bathed in natural light and fresh air, and your indoor climate will feel fresher than ever, as you can easily ventilate and replace stagnant air.

This transformation is a testament to the power of the roof window. It's more than a fixture; it's a gateway to a fresher, more inviting environment. You'll want to spend more time here.

Explore the VELUX product range and discover how you can brighten up your house and fall in love with your home once again.

Window sizes and types

When you consider what roof window type to purchase, the slope of your roof will decide if you need to look for a pitched rooflight or a flat roof window. 

Once you’ve learned which type of roof window you need, the next thing you should consider is the size and the number of roof windows you'd like to install.

Big roof windows for big views

For pitched roof windows our 2in1 or 3in1 offers you the opportunity to combine several windows in one installation, while increasing the feeling of space and opening up your space to a wide, panoramic view.

The 3in1 is ideal for medium to large rooms and can be combined with separate windows for even bigger rooms.

The 2in1 lets you double the daylight compared to a single roof window and has a modern and aesthetic design with one fixed and one openable frame.

Combined solutions for more daylight

The combined solutions are available in several sizes and variations with double or triple glazed options. The sleek design and slim profiles increase the amount of daylight in your home.

Combined roof window frames are the new standard for those looking to enhance the amount of daylight and open up their homes to the outdoors, creating spectaculars views to the outside.

Brighten up smaller rooms with a single roof window

But perhaps our single roof window is considered the standard roof window by many, and it is a delightful way to brighten rooms and create a fresher indoor climate with ventilation.

The single, standard roof window is ideal for smaller rooms, bathrooms, staircases and corridors.

Windows for flat roofs

Our windows for flat roofs also come in many different shapes and sizes ranging from the flat glass rooflight to our new generation curved glass rooflight.

The unique curved-shaped glass top allows rainwater to easily drain off the surface – even on 0° roof pitches.

All our roof windows are weatherproof, and with double or triple glazing you greatly enhance the insulation and minimise the noise coming from outside in case of heavy weather or traffic.

For flat roofs, we also offer domes either with glazing, or without glazing for installation in uninhabited rooms or buildings such as warehouses, industrial buildings, sheds, garages and more.

You can choose our pre-defined variants or build your own window from pre-selected features and sizes.

VELUX roof windows to suit all needs

VELUX roof windows are available in different types. They can be fixed or with the option for ventilation. Choose either manual, electric or solar roof windows, double- or triple glazed.

For solar or electric roof windows, you never have to worry about rain when you air out your rooms. The rainwater sensor automatically closes the roof window in the event of rain.

Is your property a listed building or located in a conservation area? Don't worry, you can still add beautiful skylights to your remodelling project. Choose VELUX heritage conservation roof window, and contact us to learn about sizes, specifications and permissions.

Are you uncertain if there is enough room to fit a rooflight? Don’t worry. In case of limited space, we offer sun tunnels and light tubes to channel and reflect the daylight into windowless rooms such as bathrooms, corridors or dark kitchens.

Remember that you can control the light with a variety of blinds and shutters or awnings, for total blackout solutions, insect screens, heat control and more. See the types, styles and variations and let us guide you towards the best choice of original blinds.

Choose VELUX for a lasting solution

A VELUX roof window is considered the original roof window. Not only because we've been supplying high quality roof windows and skylights for 80 years, but also because of the excellent features of our products giving you the ideal combination of light, air and view.

Suitable for any purpose, whether you’re building a new house, retrofitting your attic or modernising your home, you’ll always find the right solution with VELUX.

Contact our Daylight Design Advisors to learn more about how domes or flat roof windows can benefit your indoor environment. Our professionals are always ready to guide you to the best solutions and match your needs.