A roof lantern is a raised, multi-panel glazed structure fitted to a flat roof to flood the room below with daylight and add height and architectural drama. This is most popular on kitchen extensions, orangeries and open-plan living spaces.
Choosing the right one comes down to a handful of decisions: style, frame material, glazing and U-value, size, and budget. This guide walks through each of the options, compares the leading brands we supply, and answers the questions we’re asked most.
With over 43 years of experience in rooflights, skylights and smoke vents, our knowledge team are on hand to talk you through what you need. Just give us a call, and we'll be happy to help! 01276 450626.
Key takeaways
- Five decisions get you to the right lantern: style, frame material, glazing & U-value, size, and budget.
- Aluminium gives the slimmest sightlines and the biggest spans; uPVC is the cost-conscious option with strong thermal performance. We don’t supply timber.
- For Building Regs, compare the whole-unit U-value (assessed horizontally), not the lower glazing figure. In England, the limit is 2.2 W/m²K and every lantern we supply sits comfortably inside it.
- Size it at roughly 15–20% of the room’s floor area, and measure the builder’s kerb, not the ceiling opening.
- Prices run from around £855 (Korniche) to £2,325+ (frameless Thermalight), supplied. We offer a Guaranteed Price Match and free UK mainland delivery on all of our products.
What is a roof lantern?
A roof lantern sits above the roofline as a three-dimensional glazed feature, unlike a flush rooflight or skylight that sits level with the roof. In addition to the extra light it can provide, its raised structure lifts the internal ceiling height, making a flat-roof extension feel noticeably larger and more open.
Quick definitions:
- Roof lantern (also lantern roof, lantern skylight) is a raised, pitched, multi-panel structure; the biggest architectural statement and the most light.
- Rooflight / skylight is a flat or low-profile glazed unit set into the roof.
- Roof window is typically an outward- or centre-pivoting window in a pitched roof.
All of the above options will suit flat roofs; however roof lanterns make the strongest design feature and can create the wow factor in many homes.
Why choose a roof lantern?
- Maximum daylight - light enters from every angle, far more than a flush rooflight.
- A sense of space - the raised structure adds ceiling height and volume.
- Energy savings - more natural light means less artificial lighting; double glazing with an argon-filled cavity (standard on our range) improves heat retention by up to ~30%, with triple glazing available for even better insulation and noise reduction.
- Kerb appeal and value - a striking centrepiece inside and out.
How to choose a roof lantern
1. Style - contemporary or traditional?
For the best solution, it is often best to match the lantern style to the building. On a modern extension, a slim contemporary lantern becomes a clean architectural feature; on a period or listed property, a more classic look (or a design that blends with the existing building) may be required. Internally, the number of glazing bars sets the character. A 4-panel frame gives clean, contemporary sightlines, while a 6-panel design adds two glazing bars for a more traditional feel (and helps where site access is limited).
2. Frame material - aluminium vs uPVC
- Aluminium is the most popular choice: super-strong yet light, giving the slimmest sightlines, the biggest spans, and powder-coating in virtually any RAL colour (many brands offer a different colour inside and out). This can often provide the best all-round performance and longevity. Our aluminium lanterns: Korniche, Brett Martin, Thermalight, Skylantern, Lunaglaze.
- uPVC is the cost-conscious option with strong thermal performance and no painting. The frames are often a little chunkier and colour choice narrower, but modern systems are thermally broken for warmth and condensation resistance. Our uPVC lantern: Wendland.
- Timber provides a warm, period look, but it needs regular maintenance and rarely matches aluminium’s slim sightlines or thermal figures. We specialise in aluminium and uPVC and don’t supply timber. For most projects, a powder-coated aluminium frame gives the closest classic-to-contemporary finish with far lower upkeep.
3. Construction type
There are generally 3 approaches to the construction types. We've covered them below, starting with the slimmest-first:
- Frameless - the latest structural-silicone glazing bonds glass-to-glass at the hip and ridge, for the slimmest sightlines and clearest views (our Thermalight range).
- Slim aluminium frame - lightweight aluminium box rafters for elegant, minimal internal lines. (Our Skylantern or Brett Martin range).
- Reinforced PVCu or aluminium ridge - a strong ridge lets slimmer rafters be used, keeping sightlines narrow.
4. Glazing & U-values (the bit worth getting right)
Double glazing with an argon-filled cavity and soft-coat Low-E glass is standard across our range; triple glazing is available where you want the best insulation and acoustic performance. There is a variety of glass options which typically include self-cleaning, solar-control (to cut summer heat gain) and laminated safety glass. The Rooflight Association recommends a laminated inner pane for overhead glazing, as it holds fragments together if broken.
Understanding U-values - compare like with like:
- Centre-pane (glazing) U-value describes the glass alone. Across our range, this reaches as low as 0.6 W/m²K with upgraded/triple glazing; most double-glazed units sit around 1.0–1.3 W/m²K.
- Whole-lantern U-value - the U-value is assessed horizontally, based on the lantern’s developed surface area and includes the frame, is higher, and varies with size. This is the figure Building Regulations use.
In England, Approved Document L sets a limiting rooflight U-value of 2.2 W/m²K (assessed in the horizontal plane). Every lantern we supply is engineered to sit comfortably inside that, but for compliance, always compare the whole-unit figure, not the glazing figure. (Scotland, Wales and Northern Ireland have their own regulations.)
5. Size & spans
As a rule of thumb, aim for a lantern covering roughly 15–20% of the room’s floor area for balanced light without over-glazing. Our lanterns run from compact 1m × 1m units up to very large spans. The Skylantern range reaches 6m wide with no maximum length, and Korniche spans up to 6m × 4m with intermediate rafters. These options ensure that big, open extensions are well catered for. Measure the external weathered kerb (the builder’s upstand the lantern sits on), not the ceiling opening; if in doubt, send us your dimensions for a free check.
6. Pre-assembled or kit form?
For the fastest fit, lanterns can be delivered pre-assembled in one piece to drop straight onto the kerb. Where access is restricted, they’re supplied in kit form for on-site assembly (some, like Korniche and Wendland, are delivered unglazed with the glass separate). Every lantern comes with drawings and installation instructions, and we are able to advise if there is anything that you're not sure about with the product you purchase.
7. Opening & ventilation
Most roof lanterns are fixed, but ventilation options (such as manual or electric single-bay roof vents on Skylantern) are available if you want to add airflow. This can be particularly useful in a kitchen. Ask us about opening options for your chosen system.
Roof lantern brands compared
Every lantern we supply is UK-made and comes with a 10-year warranty. Here’s how the six brands compare at a glance - tap a brand name to see the full range.
| Brand | Frame | Style | Glazing U-value* | Max span / sizes | Standout | From (inc VAT) |
|---|---|---|---|---|---|---|
| Korniche | Die-cast aluminium | Modern take on a Victorian design | 1.0–1.2 | Up to 6m × 4m (with rafters) | 6 self-cleaning glass options; award-winning slim rafters | £854.51 |
| Skylantern | Aluminium | Minimal, ultra-low sightlines | 1.2 double / 0.9 triple (rafter) | Up to 6m wide, no max length | Huge spans; variable pitch; roof-vent option | £922.00 |
| Wendland | uPVC | Modern, cost-conscious | 1.2 | 10 stock sizes | RidgeLOCK easy-fit; thermally broken uPVC | £988.28 |
| Lunaglaze | Aluminium (38mm rafters) | Slim, premium | 1.3 | 6 standard sizes | Fits in ~40 minutes; BS6375 weather-tested | £1,299.00 |
| Brett Martin | Thermally broken aluminium | Contemporary (4-panel) / classic (6-panel) | 1.2 | Up to 3000 × 2000mm + bespoke | Toughened std, laminated upgrade; self-clean | £1,258.15 |
| Thermalight | Frameless aluminium | Contemporary, slimmest sightlines | as low as 0.6 (upgraded) | Pyramid & Octagonal | Frameless structural glass; Part Q / Secured by Design | £2,325.00 |
*Centre-pane (glazing) U-values (W/m²K) — not whole-unit. All are UK-made with a 10-year warranty. Ask us for the whole-unit U-value for your size, or browse the full range on the roof lanterns category page.
How much does a roof lantern cost?
Roof lanterns in our range start from around £855 inc VAT for a compact aluminium Korniche and rise to £2,325+ for a premium frameless Thermalight. As a guide:
- Entry / best value: from ~£855 (Korniche)
- Mid-range aluminium & uPVC: ~£920–£1,400 (Skylantern, Wendland, Brett Martin, Lunaglaze)
- Premium / frameless: £2,300+ (Thermalight)
Price is driven by size, frame material, glazing spec (self-cleaning, solar-control, triple glazing and laminated safety glass all add cost), colour finish and shape. These prices are for the lantern supplied. Fitting is carried out by your own builder and isn’t included. Every order comes with our Guaranteed Price Match and free UK mainland delivery.
Do I need planning permission?
You don't usually require planning permission for a roof lantern, particularly where you are fitting the lantern to an existing flat roof, as this sits under permitted development. This is provided it doesn’t rise more than 150mm above the existing roof plane, and the property isn’t listed or in a conservation area. Those cases, and some flats, have tighter rules, so it is also worth checking with your local planning authority if unsure. A new extension has its own planning considerations, separate from the lantern. Note: responsibility for confirming that any component meets the relevant Building Regulations rests with the client or specifier.
Installation & maintenance
Roof lanterns fit onto a prepared builder’s kerb and are typically a one-day job for a competent builder, although some systems can be fitted in under an hour. Maintenance is minimal, particularly with options in the range that include self-cleaning glass (standard on much of the range), which uses a coating that breaks down dirt in daylight and rinses clear in the rain, so a lantern high on a roof largely looks after itself.
Ready to choose?
- Buy online - if you know the type, size and finish, shop the full range on the roof lanterns category page.
- Bespoke - custom sizes and shapes are available; call 01276 450626 if you can't find what you need, or are looking for something outside of the off-the-shelf products.
- Need help? Our experienced sales team will help you choose the right lantern for your project and budget. Call 01276 450626, and we’ll talk it through.
