Can You Add Skylights on Roof You Already Have? 7 Key Things to Know First

1. Yes, You Can Add Skylights on Roof—But It Depends on the Structure

Not all roofs are created equal. The framing underneath your shingles plays a key role in whether skylights can be added. Rafters and trusses must be assessed to make sure they can handle the opening and the added load.

In general, roofs under 20 years old and in good condition are strong candidates. According to the National Research Council of Canada, any roof modification that involves structural framing must comply with national and provincial building codes to ensure safety and durability.

Before adding skylights on roof, have a professional inspect your structure. Even a small shift in design requires proper support.

2. Skylights vs Roof Windows: What’s the Difference?

The terms are often used interchangeably, but there’s a subtle difference. Roof windows typically open like a traditional window and are installed within reach, making them easy to operate and clean. Skylights on roof, especially those used in vaulted ceilings or higher placements, may be fixed or operated remotely, often designed more for daylight than ventilation.

Brands like Skylights Velux offer both types, with features like solar-powered blinds, rain sensors, and energy-efficient glazing. Choose based on your space, accessibility, and how much ventilation or natural light you want.

Roof windows are great for lofts, attic conversions, and second-floor bedrooms where you can easily reach the opening. Skylights, on the other hand, are more popular in kitchens, hallways, bathrooms, and living rooms—places where natural light is welcome but access may be limited.

3. Best Season to Install Skylights on Roof

You can install skylights on roof anytime, but spring and early summer are ideal. Milder weather lowers the risk of water intrusion during installation and helps sealants bond properly.

Environment Canada recommends scheduling construction projects during dry seasons to avoid delays—especially in coastal areas with heavy rainfall like Vancouver or Victoria.

If you live in a colder region, installing in late spring also reduces the risk of thermal expansion issues that can affect flashing and caulking.

4. Installing a Skylight Without a Full Roof Replacement

It’s a myth that adding skylights on roof always requires replacing the whole roof. If your current roof is in good shape—with no leaks, sagging, or major wear—a skilled contractor can carefully:

• Cut an opening
• Reinforce the framing
• Insert the skylight
• Flash and seal the area for weather protection
  
  

This process minimizes disruption and preserves your existing roofing system. Of course, if your roof is nearing the end of its lifespan, consider combining skylight installation with roof replacement to save on future labor and costs. Professionals may also suggest placing skylights on the sunniest side of the house to maximize natural light, reduce reliance on artificial lighting, and boost energy efficiency—especially during long winter months.

5. Why Some Skylights on Roof Leak—And How to Prevent It

Leaks are one of the most common problems after a skylight is installed. But the good news is—they’re completely avoidable with proper planning and installation.

Here’s what usually causes them:

• Poor flashing or sealing
• Incorrect slope or placement
• Use of low-grade materials
  
  

These issues can lead to water infiltration, structural damage, and even mold if left unaddressed. Stay ahead of problems by watching for early warning signs like condensation, drafts, bubbling paint, or ceiling stains near the skylight. If needed, schedule prompt skylights repair to prevent expensive interior damage.

Also, ensure your skylight has proper insulation around the frame. This not only reduces heat loss in winter but also helps prevent condensation and maintains indoor comfort year-round.

6. Choosing the Right Skylights on Roof for Your Space

The best skylights on roof are the ones that suit your roof type, room function, and daylight goals. Choosing the right skylight isn’t just about aesthetics—it’s about maximizing comfort and energy efficiency throughout your home.

For example:

• Vented skylights in bathrooms help with humidity and improve air circulation.
• Fixed skylights in stairwells brighten dark corners and make narrow spaces feel more open.
• Tubular skylights in hallways offer soft daylight without taking up ceiling space or requiring major structural changes.
  
  

Modern options like Skylights Velux come with features like built-in blinds, solar-powered openers, and rain sensors that automatically close the skylight when bad weather hits. If your goal is passive solar gain, moisture control, or natural ventilation, your installer can guide you toward the most effective unit type, ideal placement, and energy-efficient glazing for your specific needs.

7. Professional Help Matters More Than You Think

Adding skylights on roof is not your average DIY project. A certified roofer will ensure structural compliance, proper flashing, and energy-efficient results.

According to NRC Canada, any roof modification involving openings or ventilation must meet the National Building Code. Hiring a professional ensures you meet these requirements—and get warranty protection, too.

Plus, expert installers can help you avoid common mistakes like placing skylights too close to chimneys or vents, which could create airflow issues.

Final Thoughts

Can you add skylights on roof that’s already there? Yes, you definitely can. It’s a great way to bring in more natural light, make your space feel more open, and even improve energy efficiency—without having to build a whole new roof.

Here are a few things to keep in mind:

• Get a roof inspection first.
• Choose the right kind of roof windows or skylights velux for your needs.
• Check the weather forecast and plan for a dry day.
• Hire a licensed professional for the skylight installation.
  
  

With the right prep, installing a skylight in your current roof can be one of the best upgrades you’ll make. Whether you’re lighting up a dark hallway or adding sunshine to your favorite reading spot, skylights on roof offer both style and function.

Just don’t forget about maintenance. Over time, even well-installed skylights can develop issues. If you already have them and aren’t sure how they’re holding up, check out these 7 Clear Signs That Your Skylights on Roof Need Replacement.