Installing a roof window: the complete guide

Choosing the right type of opening for your roof windows depends on your living space and specific needs. Here are the main options:

The pivot window: When opened, the top part tilts inward, and the bottom part tilts outward. This design allows you to make the most of the space beneath the window, depending on its height.

The projection window: This outward-opening window provides a stunning, unobstructed view. Even if positioned high up, it is easy to operate using a control bar or even your smartphone.

The side-hinged window: Opening like a standard window, this option is versatile and compatible with all types of roofs.

Explore online resources for the latest innovations in roof windows, including user reviews and expert recommendations.

For further guidance, you can check an article such as How to choose the right roof windows for your attic? 

Installing a roof window is a complex task that requires expertise in carpentry or joinery. Unless you are an experienced DIY enthusiast with advanced skills, it’s best to leave this job to a professional.

Even with an assembly manual, challenges may arise, such as:

• Choosing the right location for the window
• Understanding the roof structure and respecting the correct slope
• Fixing the frame securely
• Cutting through the roof, installing the underlay, and finishing the work
• This job also requires specialised tools, including a reciprocating saw, spirit level, rafters, and an insulation knife.

For the best results and optimal safety, hiring a certified professional is strongly recommended. Professionals ensure the work meets the highest standards, giving you peace of mind.

Timeline:

• Replacement of an identical roof window: Around half a day
• Installation of larger windows or new combinations: Approximately two days

Installing a roof window involves multiple steps, from preparing the frame to finishing the exterior cladding. Here are the 10 key steps followed by our VELUX-certified installers:

1. Verify the specifications: Check that the new window matches your project requirements, including the manufacturer's details, model, dimensions, options, and colour.
2. Remove the old window (for replacements): The installers take out the existing roof window and surrounding coverings, such as tiles.
3. Determine the ideal position (for new installations): They calculate the best height for the window based on the room's dimensions, cut the underlay screen, and remove tiles.
4. Prepare the frame: Using a handsaw or reciprocating saw, the rafters are cut, and the support structure is created with a drill driver.
5. Install the frame: The frame is secured to the rafters, and the connection kit is fitted. The tiles are adjusted to match the contours of the frame, and levels are checked.
6. Enhance insulation and waterproofing: An interior lining is added to improve insulation and ensure the installation is watertight.
7. Install the exterior cladding: Exterior cladding is fitted, and tiles are cut with a grinder if needed.
8. Finish the interior: The surrounding partition is plastered to close the opening around the window, and tiles are replaced.
9. Fit additional accessories: Depending on your project, the blinds, roller shutters or solar shutters are installed.
10. Enjoy the transformation: Your roof window is now ready to bring in natural light and fresh air!

If you are replacing your roof window with an identical model (same dimensions, materials, and colour), planning permission is typically not required.

Most homeowners opt to replace their old windows to improve thermal efficiency or add modern features, such as double glazing or motorised roller shutters.

If you plan to install a new roof window, change the model, or add features like roller shutters, you may need to notify your local planning authority or obtain permission.

This requirement arises because such changes modify the external appearance of your property. The process is generally straightforward and allows authorities to ensure compliance with local building or planning regulations.

If your project is part of a larger renovation or extension exceeding a specific size threshold, such as adding a significant amount of floor space, you may need to apply for a formal building permit.

To confirm what is required in your area, check with your local planning authority or government website for detailed guidance.

When installing a roof window, you must consider rules that prevent overlooking neighbouring properties and help avoid potential disputes:

• Direct view (e.g., overlooking a garden or living space): Maintain a sufficient distance between your window and the boundary of your neighbour’s property. Local regulations often specify minimum distances.
• Oblique view (e.g., when you must lean out to see the neighbouring property): Some jurisdictions require a smaller minimum distance for this type of view.
• No view (e.g., facing a blank wall or open sky): Many areas do not impose minimum distance requirements in such cases.

Check with your local building or planning authority to confirm the specific rules in your area.

Adding a roof window to your home can be a cost-effective way to enhance your living space. On average, the price of a VELUX roof window, including VAT but excluding installation, ranges from €340 to €2,095 (PLEASE, LOCALISE). The cost of a roof window depends on several factors, such as:

• Material: Options include wood, PVC, or aluminium.
• Glazing: Single, double, or triple glazing for better insulation and efficiency.
• Quality: The overall build and brand can influence price.
• Opening system: Choices range from pivot or projection windows to motorised options.
• Installation: The complexity of installation affects labour costs.
• Accessories: Blinds, shutters, or other add-ons can increase the budget.

To get an accurate estimate, consult local suppliers or professional installers who can provide tailored advice based on your preferences and project scope.

Replacing an old roof window with a more energy-efficient model could make you eligible for financial incentives.

Many governments and local authorities offer subsidies or grants to support energy-efficient renovations. These programmes often include projects like upgrading from single to double glazing. Examples of common incentives include:

• Reduced VAT or sales tax for renovations on older properties
• Energy renovation grants or subsidies
• Low-interest or zero-interest loans for energy-efficient upgrades
• Local incentives or rebates

Eligibility requirements vary by location, but using a certified professional (e.g., an accredited installer) is often necessary to qualify.

Check with your local government or energy agency for details on available programmes and eligibility criteria.

Installing roof windows is an excellent way to enhance your home, bringing in more natural light and creating a welcoming space.

For the best results, consult a professional who can guide you on the optimal placement, the most suitable window type, and compliance with local regulations.