What is a Velux Window?
When you're planning a loft conversion, one of the most important decisions you'll make is how to bring natural light into the space. A dark loft can feel cramped and uninviting, but the right windows can completely transform it into a bright, welcoming room. That's where Velux windows come in, and they're often the perfect solution for many loft conversions.
What is a Velux Window?
Velux is actually a brand name, much like Hoover became synonymous with vacuum cleaners or Biro with ballpoint pens. The company has been making roof windows since 1941, and they've become so popular that many people now use "Velux window" to refer to any roof window, regardless of who actually made it.
Technically speaking, a Velux window is a roof window that sits flush within the plane of your roof. Unlike a traditional vertical window that you'd have in a wall, or a dormer that projects out from the roof, a Velux window is installed directly into the roof slope. When you look at a house from the outside, you see the window sitting neatly within the roofline without changing the profile or appearance of the property.
These windows come in various sizes and styles. You can get manual ones that you open with a handle, electric versions that operate at the touch of a button, or even solar-powered models that charge themselves during the day. Some come with built-in blinds, rain sensors that automatically close the window if it starts raining, and remote controls for hard-to-reach installations.
Velux Windows vs. Skylights vs. Dormers
There's often confusion about the difference between Velux windows, skylights, and dormers, so it's worth clarifying what sets them apart.
Velux Windows (Roof Windows)
As we've mentioned, Velux windows sit flush with your roof and can be opened for ventilation. They're installed between the rafters and follow the pitch of your roof. You can reach them to open and close them, and they're designed as functional windows rather than just sources of light.
Traditional Skylights
Skylights are usually fixed panels of glass set into the roof that don't open. They're purely for letting light in rather than providing ventilation. In modern loft conversions, we rarely use fixed skylights because opening windows are so much more practical and provide better ventilation.
Dormers
Dormers are completely different because they actually project out from the roof, creating a box-like structure with vertical walls and their own mini roof. Dormer windows sit in these vertical walls, just like normal house windows. Dormers add both headroom and floor space to a loft conversion, but they also change the external appearance of your property and usually require planning permission.
The big advantage of Velux windows over dormers is that they maintain your home's existing roofline. From the street, your house looks essentially the same as it always did. This is particularly important if you live in a conservation area, have restrictive covenants, or simply prefer not to change how your home looks from the outside.
Cost-wise, Velux windows are significantly more affordable than building dormers. A dormer involves constructing a whole new structure with walls, a roof, and windows, whereas a Velux window is installed directly into your existing roof with minimal structural work needed.
Why Velux Windows are Perfect for Loft Conversions
There are several compelling reasons why Velux windows work so well in loft conversions, and why we often recommend them to our clients.
Incredible Natural Light
This is the big one. Roof windows let in up to 40% more light than vertical windows of the same size. That's because they're angled toward the sky rather than looking straight out horizontally. Throughout the day, you're capturing light from above, which floods the space much more effectively than a window in a wall would.
When Laura came to us for her Velux conversion, the transformation in terms of light was remarkable. What was previously a dark, unused loft space became a bright, airy bedroom that feels welcoming at any time of day. The Velux windows made all the difference.
Maintains Your Home's Appearance
If you love how your house looks from the outside, Velux windows let you keep that kerb appeal intact. Because they sit within the existing roofline, most people walking past won't even notice you've had work done unless they look quite carefully. This is a huge advantage over dormers, which dramatically change how a property looks.
This also means that in most cases, you won't need planning permission for Velux windows. They're considered permitted development, which saves time, money, and the uncertainty of waiting for planning approval. There are some exceptions (like if you live in a conservation area or your property is listed), but for most standard houses, Velux windows can be installed without planning permission.
Cost-Effective Solution
Compared to building dormers, installing Velux windows is much more affordable. You're not constructing new walls and roofs; you're simply creating openings in your existing roof structure and fitting the windows into them. This means less labour, less materials, and a faster installation process.
For a family like Laura's who needed an extra bedroom but wanted to keep costs reasonable, a Velux conversion was the perfect balance between functionality and budget.
Energy Efficiency
Modern Velux windows are highly energy efficient with excellent insulation properties. They come with double or even triple glazing, and the frames are designed to minimize heat loss. Many have energy ratings that are just as good as (or better than) your existing house windows.
This means you're not creating cold spots in your loft conversion. The room stays warm in winter and doesn't get unbearably hot in summer, especially if you choose windows with solar-control glazing.
Views of the Sky
There's something quite special about lying in bed and being able to look up at the sky, clouds, and stars. Velux windows give you that connection to the outdoors that vertical windows simply can't provide. Whether it's watching the clouds drift by during the day or stargazing at night, roof windows offer views that many of our clients tell us they absolutely love.
Quick Installation with Minimal Disruption
Installing Velux windows is relatively quick compared to other aspects of a loft conversion. Once the opening is created in the roof, the window itself can often be fitted in a day. This contributes to keeping the overall project timeline manageable and means less disruption to your family life.
Types of Velux Windows
Not all Velux windows are the same, and choosing the right type for your loft conversion makes a real difference to how practical and comfortable the space is to use.
Top-Hung vs. Centre-Pivot
Top-hung windows are hinged at the top and open outward from the bottom. They're great for situations where you want an unobstructed view when the window is open, and they're particularly good if the window is at a lower level where you might want to lean out.
Centre-pivot windows rotate around a central axis, which means the top swings inward while the bottom swings outward. These are the most common type and are incredibly practical because you can rotate them fully for easy cleaning of the outside glass from inside your loft. They're also easier to reach if your window is positioned a bit higher up the roof slope.
For most loft conversions, we recommend centre-pivot windows because they're just more practical for everyday use and maintenance.
Manual, Electric, or Solar-Powered
Manual windows open with a handle that you turn or a control bar that you operate. They're the most affordable option and work perfectly well if your windows are within easy reach.
Electric windows are operated by a wall switch or remote control. These are brilliant if your window is high up or difficult to reach, or if you just prefer the convenience of push-button operation. You can also get them with rain sensors that automatically close the window if it starts raining, which is genuinely useful if you're out at work during the day.
Solar-powered windows have a small solar panel that charges a battery, which then powers the opening mechanism. You get all the benefits of an electric window without needing to run electrical wiring to the window itself.
Different Sizes
Velux windows come in a range of standard sizes, usually designated by codes like CK04, MK06, PK10, and so on. The codes tell you the dimensions, with the first letter indicating the width and the numbers indicating the height.
For example, a PK10 window (which we installed over the bath in the Harpers' project) is larger and lets in more light, making their bathroom feel much more spacious and pleasant than it would with a smaller window.
When we're planning your loft conversion, we'll recommend window sizes based on the room dimensions, the roof slope, and how much light you want. Sometimes one large window is perfect; other times, a couple of smaller windows positioned strategically works better.
Special Features
Modern Velux windows can come with all sorts of additional features. You can get them with:
Built-in blinds (blackout or venetian) that sit between the panes of glass
Rain sensors that close the window automatically when it detects rain
Remote controls for easy operation from anywhere in the room
Smart home integration so you can control them from your phone
Enhanced security features with multi-point locking
Noise-reduction glazing if you live near a busy road or flight path
Not everyone needs all these features, but it's good to know they're available if you want to make your loft conversion as comfortable and convenient as possible.
Installation Considerations
While Velux windows are relatively straightforward to install compared to other window types, there are still some important considerations that affect where and how they're positioned.
Roof Pitch
Velux windows work with roof pitches from 15° to 90°, though the most common range is between 20° and 50°. Your roof pitch will partly determine which windows are suitable and how they'll operate. This is something we'll assess when we first survey your property.
Positioning for the Best Light
Where we position your Velux windows makes a big difference to how effective they are. Windows on a south-facing roof slope will let in more light throughout the day than those on a north-facing slope. East-facing windows give you lovely morning light, while west-facing ones capture the evening sun.
We'll work with you to decide the best positions based on how you'll use the room and what you want from the space. For a bedroom, you might want to avoid having windows directly above where the bed will be (unless you enjoy being woken by the sun). For a home office, you might want to position windows to avoid screen glare.
Multiple Windows
Sometimes one Velux window is enough, but often we'll install two or more to ensure the space gets adequate light throughout the day. The building regulations specify minimum amounts of glazing for habitable rooms, so the number and size of windows needed will partly depend on the size of your loft conversion.
Multiple windows also give you better ventilation. Being able to open windows on different parts of the roof creates a nice through-flow of air, which keeps the loft comfortable even on warm days.
Building Regulations
All Velux windows need to meet building regulations for things like thermal efficiency, safety glazing, ventilation requirements, and fire escape considerations. This is all built into the planning and installation process, and building control will check that everything is compliant.
The good news is that Velux windows are designed with building regulations in mind, so as long as they're installed properly, they'll meet all the necessary requirements.
How Much Do Velux Windows Cost?
Velux window costs vary depending on the size, type, and features you choose. A basic manual centre-pivot window might cost a few hundred pounds, while a larger electric window with solar power and rain sensors could be over a thousand pounds.
Installation costs are typically included in your overall loft conversion quote. Because the windows are fitted as part of the roofing work, they're integrated into the project rather than being a separate job.
When you consider that Velux windows are significantly cheaper than building dormers (which can cost many thousands of pounds), they represent excellent value, especially given how much light they bring in and how they maintain your home's appearance.
Long-Term Value and Energy Savings
Beyond the initial cost, Velux windows can actually contribute to energy savings over time. Their excellent insulation properties mean less heat loss in winter, and if you choose windows with solar-control glazing, you'll reduce heat gain in summer too. This can genuinely make a difference to your heating and cooling costs.
They're also durable and long-lasting. A properly installed Velux window should give you decades of trouble-free use, and because you can rotate centre-pivot windows fully inward, they're easy to keep clean and maintain.
Making the Right Choice for Your Loft
Whether Velux windows are right for your loft conversion depends on several factors, including your budget, how you want the property to look from outside, and whether you need the extra headroom that dormers provide.
For many of our clients, Velux windows are the perfect solution. They provide brilliant natural light, they're cost-effective, they don't require planning permission in most cases, and they keep your home looking much as it always has. When Laura chose a Velux conversion for her growing family, these were exactly the factors that made it the right decision for her.
If you're trying to decide between Velux windows and dormers for your loft conversion, we're always happy to talk through the options with you. We can show you examples of both, discuss the costs and benefits, and help you make the choice that's right for your home and your family.
Get in touch with Raise the Roof for honest, expert advice on the best approach for your loft conversion. We'll assess your property and give you clear guidance on what will work best for your specific situation.