Can You Upgrade an Old Plastic Skylight to a Modern Glass Rooflight?
If you’ve got an older plastic skylight on your roof, chances are it’s starting to show its age. So it’s no surprise many homeowners ask: can you upgrade an old plastic skylight to a modern glass rooflight? The answer is yes – in most cases, you can. And in many situations, it’s a worthwhile upgrade that improves both performance and appearance.
In this guide, we’ll walk through what’s involved, what to consider, and why switching to glass can make a big difference.
Why Replace a Plastic Skylight?
Older skylights were often made from plastic materials like acrylic or polycarbonate. While these were once popular, they come with several drawbacks over time.
Common issues include:
- Discolouration – plastic can yellow or become cloudy
- Scratches – surface damage affects clarity
- Poor insulation – leading to heat loss
- Condensation – especially in colder months
- Leaks or seals failing
These problems not only affect how your rooflight looks but also how it performs.
Upgrading to a modern glass rooflight addresses many of these issues in one go.
What’s the Difference Between Plastic and Glass Rooflights?
The biggest difference comes down to performance and longevity.
Plastic Skylights:
- Lightweight
- Lower upfront cost
- Prone to ageing and damage
- Limited thermal performance
Glass Rooflights:
- Clear, long-lasting finish
- Stronger and more durable
- Better insulation
- Higher resistance to weathering
Modern glass rooflights are designed to meet current building standards, offering improved energy efficiency and a much cleaner appearance.
Can You Replace Like-for-Like?
In many cases, yes. If your existing skylight sits on a flat roof upstand (kerb), it may be possible to remove the old unit and replace it with a new glass rooflight of a similar size.
However, there are a few important factors to check:
- The condition of the existing upstand
- The size of the opening
- The structural integrity of the roof
- Compatibility with the new rooflight system
Sometimes, the existing kerb can be reused. In other cases, it may need to be replaced to suit the new unit.
Do You Need to Change the Upstand?
Not always, but often. Older plastic skylights were designed differently from modern glass systems. This means:
- The fixing points may not align
- The insulation levels may not meet current standards
- The overall design may not suit a glass unit
Many modern rooflights are supplied with their own kerb or upstand, designed to work as part of a complete system.
This can actually simplify the installation and improve performance, as everything is designed to work together.
What Are the Benefits of Upgrading to Glass?
1. Improved Thermal Performance
Modern glass rooflights use advanced glazing technologies, including:
- Double or triple glazing
- Low-E coatings
- Gas-filled units
This helps reduce heat loss and improve energy efficiency compared to older plastic skylights.
2. Better Natural Light
Plastic skylights often become cloudy over time, reducing the amount of light entering the space.
Glass rooflights:
- Stay clearer for longer
- Provide better light transmission
- Create a brighter, more open feel
3. Increased Durability
Glass is far more resistant to:
- Scratches
- UV damage
- General wear and tear
This means your rooflight will maintain its performance and appearance for much longer.
4. Cleaner, Modern Design
Modern rooflights, especially frameless designs, offer a much sleeker finish.
They can:
- Sit flush with the roofline
- Provide minimal visible framing
- Complement both modern and traditional spaces
5. Reduced Maintenance
Unlike plastic, glass doesn’t discolour or degrade in the same way.
This means:
- Less cleaning
- No yellowing
- Longer-lasting clarity
Is It a Straightforward Installation?
In many cases, upgrading a skylight is relatively straightforward – especially if the existing opening is suitable.
The process usually involves:
- Removing the old skylight
- Inspecting or replacing the upstand
- Installing the new rooflight
- Sealing and finishing
If the roof structure is already sound, the upgrade can often be completed quickly.
However, every project is different, so it’s important to assess the existing setup before starting.
Do You Need Building Regulation Approval?
In some cases, yes.
If you’re:
- Changing the size of the opening
- Altering the structure
- Upgrading to meet thermal requirements
you may need to ensure compliance with current building regulations.
Modern rooflights are typically designed to meet these standards, which is another advantage of upgrading.
What Should You Consider Before Upgrading?
Before replacing your skylight, think about:
- Size and shape – will you keep the same dimensions?
- Thermal performance – what U-value do you want to achieve?
- Glazing options – clear, solar control, or privacy glass
- Installation requirements – will the upstand need replacing?
Choosing the right specification will help you get the most from your upgrade.
Is It Worth Upgrading?
In most cases, yes.
Replacing an old plastic skylight with a modern glass rooflight can:
- Improve insulation
- Increase natural light
- Enhance durability
- Reduce maintenance
- Bring the installation up to modern standards
While there is an upfront cost, the long-term benefits often make it a worthwhile investment.
When Might It Not Be Suitable?
There are a few situations where upgrading may be more complex:
- If the roof structure is damaged
- If the opening size is unusual
- If access is difficult
In these cases, additional work may be needed – but an upgrade is still usually possible.
Final Thoughts
So, can you upgrade an old plastic skylight to a modern glass rooflight? Yes – and in many cases, it’s a smart move.
If your current skylight is showing signs of wear, replacing it with a high-quality glass rooflight is one of the simplest ways to bring your roof up to modern standards – and make the most of the natural light in your home.
Modern glass rooflights offer better performance, improved durability, and a cleaner finish compared to older plastic alternatives. With the right preparation and specification, upgrading your skylight can transform both the look and efficiency of your space.
At UK Rooflights, we supply high-quality glass rooflights designed to improve performance, maximise natural light, and deliver a clean, modern finish. Get in touch today on 01709 458500 to find the right solution for your project.
