The Ultimate Guide to Planning a Pitched Roof Extension in the UK

Thinking about adding a pitched roof extension to your home? You're not alone.
Whether you dream of a light-filled kitchen-diner, a more spacious family room, or a seamless indoor-outdoor connection, a pitched roof extension is one of the most effective (and timeless) ways to increase space and add value to your property.
But here's the thing — not all extensions are created equal.
If you want your new space to feel amazing, you've got to think up. That's where frameless skylights come in — and why we're big fans of what Regal Glass Group is doing in this space.
Let's dive in.
Table of Contents
Why Choose a Pitched Roof Extension?
First, let's talk structure. A pitched roof — with its classic sloped design — offers loads of advantages over flat-roof alternatives:
✅ Better rainwater drainage
✅ A more spacious feel with vaulted ceilings
✅ Improved insulation and longevity
✅ A design that often blends naturally with traditional UK homes
Perhaps best of all, it's the perfect canvas for installing roof lights—especially the modern, clean-lined kind that give your space that high-end architectural feel.
Let There Be Light: Skylights in Pitched Roof Extensions
One of the biggest reasons homeowners choose a pitched roof extension is to flood their new space with natural light.
Adding vertical glazing like bifold or sliding doors is excellent, but the magic happens when you add skylights to the roof. The light they bring is:
Softer and more diffuse
Brighter for longer hours
Perfect for illuminating the centre of deep spaces
But which skylight is best?
Fixed Frameless Skylights: The Minimalist's Dream
While there are plenty of rooflight options out there — manual, electric, vented, and so on — we find ourselves consistently recommending one style in particular:
👉 Fixed, frameless skylights.
Why?
Because they offer:
Maximum natural light with no bulky frames
A clean, uninterrupted ceiling line that enhances modern interiors
No visible mechanisms – just pure, architectural glass
Lower maintenance (no moving parts)
Better thermal performance compared to openable alternatives
If you aim to make your pitched roof extension feel bright, clean, and effortlessly elegant, frameless skylights should be on your list.

Our Top Pick: Regal Glass Group Frameless Skylights
Regal Glass Group's frameless skylights are unparalleled in quality and design impact.
Here's why we love them:
🔹 Ultra-slim internal lines – virtually invisible framing for that glass-only look
🔹 Thermally broken frames – outstanding insulation, perfect for UK climates
🔹 High-spec glazing – available with solar control, self-cleaning glass, and even triple glazing
🔹 Custom sizing – ideal for creating dramatic feature rooflights in your extension
🔹 Designed and made in the UK – with quality control you can trust
These skylights don't just let in light—they make a statement. Whether you install one ample central roof light or a series of smaller panes between rafters, Regal's frameless range gives your pitched roof extension a wow factor that's hard to beat.
Design Ideas for Skylights in Your Extension
Need some inspiration? Here are a few ways homeowners are using frameless rooflights to level up their extensions:
✨ A central rooflight above the kitchen island to spotlight the heart of the home
✨ A series of fixed roof windows between exposed timber rafters for a loft-inspired look
✨ A glazed ridge at the apex of the pitched roof, allowing daylight to pour in from above
✨ A minimalist hallway skylight that guides you from old to new parts of the house
Frameless roof lights like those from Regal Glass Group allow for design freedom, clean shapes, stunning clarity, and no compromise on performance.
What About Planning and Building Regs?
Good news: installing skylights in a pitched roof often falls under Permitted Development — especially when the rooflight is:
No more than 150mm above the roof slope
Not higher than the ridge
Not on a side elevation (or if it is, it's obscure glazed and non-opening)
Of course, every project is unique, so it's best to check with your architect or local authority. And don't forget: Building Regulations still apply — especially for structure, thermal performance, and ventilation.
Rest assured, Regal Glass Group skylights are fully compliant with UK standards, and their team offers advice on integrating their products into your design and spec.
Conclusion: The Roof Is Just the Beginning
A pitched roof extension is more than just extra square footage—it's a chance to transform how your home feels. Combining a timeless roof form with modern glazing like Regal Glass Group's Frameless Skylights gives you the best of both worlds: classic comfort and contemporary flair.
So if you're planning an extension, don't just think about walls and floors.
Think about the sky.
🛠 Frequently Asked Questions About Pitched Roof Extensions
A pitched roof extension is a home addition with a sloped roof, typically with two sides meeting at a central ridge. It's a popular choice for kitchen extensions, rear home expansions, or side returns, offering more headroom, better drainage, and a timeless look that matches most UK homes.
It depends on your priorities. Pitched roofs often last longer, drain water better, and allow for vaulted ceilings and skylights. They can cost a bit more, but many homeowners feel the benefits are worth it, especially for long-term value and aesthetics.
Frameless fixed skylights are one of the best options. They let in tons of natural light, look clean and contemporary, and require minimal maintenance. We recommend Regal Glass Group Frameless Skylights, which are stylish, energy-efficient, and made in the UK.
Costs vary based on size, materials, and location, but a typical pitched roof extension can range from £1,800 to £2,500 per square metre. Adding features like skylights, vaulted ceilings, or high-end finishes will increase the space's cost, value, and quality.
Yes! A well-designed pitched roof extension can significantly boost your home's resale value, especially if it improves layout, adds usable space, and brings in more natural light. Buyers often see pitched roofs as a premium feature.
On average, expect 10 to 16 weeks for a standard single-storey pitched roof extension — including groundwork, structure, roofing, glazing, and finishes. Larger or more complex builds may take longer.
👷 Skylight Size By Room
Ready to bring more light into your life?
Explore Regal Glass Group's range of frameless skylights today, or speak to your builder or architect about integrating fixed rooflights into your pitched roof extension.