Your Complete Guide to Velux Windows for Loft Conversions
Here’s everything you need to know about choosing the right Velux windows. From costs and styles to planning rules and installation.
Powered By:
.png)
Here’s everything you need to know about choosing the right Velux windows. From costs and styles to planning rules and installation.
Powered By:
Velux windows are among the most popular choices for homeowners looking to brighten their lofts with natural light, improve ventilation, and make the most of their roof space. As a trusted roof window brand, Velux has become the go-to option for loft conversions, offering better insulation, a sleeker design, and longer-lasting performance than many generic alternatives.
In this guide, we’ll walk you through everything you need to know, from planning permission rules and selecting the right window style to understanding installation costs and deciding how many windows your loft needs.
You’ll also learn how Velux windows are installed, how they compare to generic rooflights, and why millions of UK homeowners trust them.
Velux windows are a popular choice for loft conversions thanks to their sleek design and ability to flood a space with natural light.
Many homeowners ask the same question before installing them: Do I need planning permission? In most cases, the answer is no.
Velux windows usually fall under permitted development rights, meaning you can install them without applying for planning permission, as long as certain conditions are met.
Under UK planning law, you can install roof windows such as Velux without formal permission, which is part of your home’s permitted development rights. These rules are designed to allow minor home improvements that don’t significantly alter the building’s external appearance or impact neighbours.
To qualify for permitted development, your Velux window installation must meet the following criteria:
While most standard Velux window installations don’t require planning permission, there are some exceptions:
If your property is in a conservation area, planning permission is usually required for any changes that alter the external appearance of your roof, including Velux windows. Even low-profile models may be scrutinised more closely, and your local authority may limit where they can be installed or how many are allowed.
In most cases, you’ll need to use Velux conservation-style windows, which feature a flush fit, black frames, and a vertical glazing bar to preserve the traditional look of the roof. Installing the window on the rear slope, out of public view, typically increases your chances of approval. If you're unsure, it’s worth submitting a pre-application enquiry or applying for a Lawful Development Certificate for clarity.
The number of Velux windows to install in your loft depends on room size, orientation, and intended use. The total window area should comprise 15-20% of the floor space.
Larger rooms may need multiple windows to distribute light evenly, while smaller rooms require only one or two. Orientation also impacts natural light levels. North-facing lofts may need more windows to maximise daylight, while south-facing spaces typically need fewer due to abundant sunlight.
The room’s purpose matters too; a home office or living space benefits from more light, whereas a bedroom may only need a few windows to create a cosy feel.Use our easy calculator below for an accurate estimate based on your room’s details.
Choosing the right type of Velux window can transform your loft, not just by adding daylight, but by shaping how the room feels and functions. Below is a quick comparison of the most popular Velux window styles, helping you weigh the key features at a glance.
Let’s look at each type of window in more detail to help you decide which suits your Velux loft conversion best:
Centre-pivot Velux windows are the classic, most versatile choice for lofts. Hinged in the middle, they rotate 180° to make cleaning effortless, especially handy in lofts with low walls or furniture beneath the window. They’re easy to open and close, even in tight spaces, and work well on most pitched roof angles.
Works well in standard Velux loft conversions and small loft layouts.
Top-hung Velux windows open outwards from the top, giving a wider, unobstructed view and extra headroom, perfect if you want to stand close to the window without ducking. These windows are particularly effective in low-pitched roofs and can add a real sense of space to smaller loft rooms.
Ideal if your loft conversion is used as a bedroom or home office with a view.
For hard-to-reach areas or a modern upgrade, Velux Integra® electric or solar-powered windows offer remote operation at the touch of a button, or via your phone. They include rain sensors, automatic ventilation, and programmable settings. These are ideal for high-ceilinged homes or those with a tech-savvy aesthetic.
Want to turn your loft into something truly special? The Velux roof terrace or balcony system opens outwards to create a mini outdoor space. A unique feature that adds real luxury and resale value. It’s ideal for master bedrooms or large open-plan lofts where you want fresh air and open views.
Note: These require more structural work and may need planning permission.
If your property is in a conservation area or you prefer a traditional look, Velux conservation windows are designed to blend in seamlessly. They feature a black external finish, central glazing bar, and a flush fitting that maintains your roof’s heritage appearance.
Often required for listed buildings and heritage zones.Approved by many local councils when standard rooflights would be rejected.
Fixed skylights do exactly what the name suggests: they bring in light, without opening. They’re perfect in lofts where natural daylight is a priority, but ventilation is handled elsewhere (e.g. mechanical fans or other openable windows).
Yes, even if you don’t need planning permission, approval of building regulations is still required when installing Velux windows.
That’s because any change that affects your roof's structure or your home's energy performance must meet current UK building standards. Your installer (or loft conversion company) is usually responsible for ensuring compliance, but it’s important to understand what’s involved.
The key areas checked under building regulations include:
You’ll need approval if you’re:
Usually, your builder will submit a Building Notice or work under a competent person scheme, so you won’t need to apply yourself. Always confirm that your installer provides final certification once the job’s complete, as this protects you when selling or insuring your home.
The cost to supply and fit a Velux window ranges from £800 to £1,800, depending on the type of installation, size, and complexity.
Here’s a table that shows the window type, supply only price and fitted costs price to help you make a better decision:
The cost of fitting a Velux window varies depending on the complexity of the job. Here’s what typically affects the price:
Always request a detailed, all-in quote that includes supply, fitting, and finishing, so there are no surprises. You can use our instant quoting tool to get some instant prices.
Several factors can impact the total cost of a Velux window installation. Larger models, conservation styles, or electric and solar-powered Velux Integra® windows are more expensive than standard centre-pivot units.
Costs also rise if structural changes are needed, such as trimming rafters or reinforcing the roof. Roof access also plays a role, with high or difficult-to-reach areas often requiring scaffolding.
Optional extras, such as triple glazing, blackout blinds, and rain sensors, will increase the price further but can improve comfort, energy efficiency, and usability in the long run.
Installing a Velux window is more complex than simply fitting a skylight. It involves structural alterations, weatherproofing, and compliance with building regulations. That’s why we always recommend hiring a certified Velux installer, especially if the window forms part of a habitable loft space.
Here’s what the full installation process typically involves:
Before any work begins, the installer will assess your existing roof structure, including the rafters, pitch, insulation, and any obstructions like pipes or beams. This ensures the opening can be safely made without compromising the structural integrity of the roof.
They’ll also confirm the correct flashing kit for your roof type (e.g. tile, slate, corrugated) and measure for the specific Velux model you’ve chosen.
Once the position is finalised, the installer will mark out the window frame area internally and externally, carried out with precision to avoid weakening the roof or creating cold bridges. This is followed by:
The window frame is fitted into the prepared opening, followed by the Velux flashing kit. A vital component that ensures a watertight seal between the window and the roofing material.
Velux flashing kits are designed for specific roof types and pitches, so correct selection and fitting is essential to avoid leaks.
This step ensures the window meets energy efficiency standards and minimises long-term issues, such as condensation or cold spots. So, with the window secured, the installer will:
If the loft is already converted or intended to be a habitable room, the final stage of installation usually involves finishing the interior around the window. This includes fitting angled plasterboard reveals to maximise light, followed by skimming, painting, and adding any necessary trims or sills. In unconverted lofts used purely for storage, these finishing touches may not be required.
The installer shouldcheck after everything has been completed:
Velux is the UK’s leading roof window brand, trusted by architects, installers, and homeowners for over 80 years. While cheaper alternatives are available on the market, Velux stands out for its exceptional build quality, innovative design, and long-term performance.
All Velux windows are BBA-certified, which means they meet strict standards for durability, weather resistance, and thermal performance. Compared to generic roof windows, Velux offers a significantly wider choice of sizes, glazing options (such as noise reduction or triple glazing), and accessories. These include blackout blinds, rain sensors, and solar-powered operation.
They’re also designed to last 20–30 years with minimal maintenance, backed by a robust manufacturer warranty and widely available replacement parts. In short, you’re paying for reliability, aesthetics, and a product made to perform over decades, not just years.
Looking for clear answers on planning permission, costs, installation, or which Velux windows suit your loft? You’re not alone, these are the most common questions homeowners ask when considering roof windows.
In most cases, no. Velux windows fall under permitted development rights, meaning you don’t need planning permission as long as they don’t project more than 150mm from the roof plane and aren’t higher than the existing roofline.
Exceptions apply in conservation areas, listed buildings, or if the window faces a neighbour and affects privacy.
As a general guide, aim for 10–20% of your floor area in window glazing. A small loft bedroom may only need two standard Velux windows, while a larger open-plan space could benefit from three or more. The final number depends on your layout, roof pitch, and how much natural light you want.
Velux offers several options: centre-pivot, top-hung, electric and solar-powered (Integra®), balcony systems, and conservation-style roof windows. Each is designed for a different type of loft conversion, ranging from compact bedrooms to luxury conversions.
Yes. Even if planning permission isn’t needed, building regulations still apply. Installing a Velux window involves structural changes and must meet standards for roof stability, insulation, ventilation, and means of escape (where applicable). A certified installer should ensure full compliance as part of the project.
Installation costs typically range from £800 to £1,800, depending on the window type, size, roof access, and whether it's a new opening or a replacement.
Basic centre-pivot windows are at the lower end, while electric and balcony-style systems are more expensive due to added features and complexity.
It’s possible if you have strong DIY experience, but it’s generally not recommended. Installation involves cutting into the roof, fitting flashing kits correctly, and meeting building regulations.
Hiring a certified installer ensures the window is watertight, structurally sound, and fully compliant.
Yes, but only the conservation-style models are typically approved. These have a flush fit, black external frames, and a vertical glazing bar to preserve traditional roof aesthetics. They are often required for listed buildings or properties in conservation zones.
