Roof lantern sizes and layout ideas

If you’re thinking about adding a roof lantern to your home, we can see why. The benefits of these products are incredibly enticing, such as their ability to suck in natural light from all angles, offer stargazing opportunities at night, and provide your space with elite thermal performance.

Roof lanterns sit on top of a flat roof, and are glazed structures connected by either uPVC or aluminium frames. It’s natural to look up at your ceiling and wonder if it could accommodate a roof lantern. Is the surface area big enough? Is it the right shape?

The good news is that at Unique Glazing, our roof lanterns are made bespoke, so we have control over the size. There are a few preset sizes that are popular across London, including  2m x 1m, but we can accommodate anything up to 2.4m x 5.4m for uPVC, and 6m x 4m for aluminium.

Pretty much all roof lantern projects in the capital sit below those thresholds anyway, so you can rest assured that even with limited space, your home’s new standout feature can still attract light from all angles.

Common roof lantern sizes in UK homes

While every home is different, there are a few standard sizes that tend to crop up time and time again across UK extensions.

Small roof lanterns (1m x 1m to 1.5m x 1m)

Ideal for a cosy kitchen, utility space or smaller dining nook, these compact lanterns add plenty of light without dominating the room. They’re a great way to let natural light into smaller areas, and are a good choice if you’re not looking to invest much.

Medium roof lanterns (2m x 1m to 2m x 1.5m)

A popular choice for average-sized kitchen diners and family extensions. This size of roof lantern offers enough light to brighten the whole room while keeping costs down.

Large lanterns (3m x 2m and above)

Bigger roof lanterns suit open-plan spaces, grand living room schemes and ambitious orangery builds. Our Korniche roof lantern sizes go all the way up to 6m x 4m for those wanting maximum sky views.

Custom sizes

If none of the standard sizes suit your project, we can manufacture a roof lantern to your exact specifications, up to our size thresholds mentioned above. You’ll still get the same quality.

How to choose the right roof lantern size

Choosing the ideal size of your roof lantern isn’t just about picking the biggest one you can afford. A few key factors come into play.

Room dimensions

A good rule of thumb is that your roof lantern should cover roughly a third of the ceiling area. Too small and you won’t get enough light; too large and the proportions feel off.

Ceiling height and roof structure

Lower ceilings benefit from slimmer profiles like the Korniche aluminium lantern, which keeps things looking clean. Always check that your roof structure can support the lantern, and for larger projects, a structural engineer may need to be involved.

Budget

Bigger lanterns use more materials and glass, so naturally they cost more. Setting a clear budget early helps narrow down your options before the final decision.

What are the benefits of a roof lantern?

Roof lanterns look great, but they have several other benefits you may not be aware of.

Loads of natural light

The biggest draw is how much natural light they let in, regardless of the time of day or where the sun is (if it’s out at all), brightening even the darkest corners of your extension.

Thermal performance and energy efficiency

Modern roof lanterns are built with advanced thermal break technology (a clever barrier that stops heat escaping through the frame), keeping your home cosy in winter and cool in summer. This boost to energy efficiency, simply put, helps cut your heating bills.

A stunning architectural feature

A roof lantern creates a dramatic effect, turning an ordinary ceiling into the focal point of the room. This is something that’s in demand, so you can expect an increase in your home’s value once you install your new roof lantern.

Sky views all year round

Whether it’s a sunny morning or a starry night, a roof lantern offers an open, expansive view that flat roof windows can’t match.

What materials are roof lanterns available in?

We offer our roof lanterns in two popular materials, each with their own strengths.

uPVC roof lanterns

uPVC (unplasticised polyvinyl chloride) is a durable, low-maintenance plastic widely used in modern windows and doors. Our uPVC roof lanterns are sourced from Liniar.

• Lasts 25-35 years with minimal upkeep
• Excellent thermal performance thanks to multi-chambered profiles
• Cost-effective for those wanting quality on a budget
• Elegant appearance that suits traditional homes
• Available with EnergyPlus twin-walled top caps for extra warmth

Aluminium roof lanterns

Aluminium is a lightweight metal that allows for slimmer sightlines and larger glass areas. Our aluminium roof lanterns come from Korniche.

• Lasts up to 45 years
• Slim frames mean more glass and more light
• Suits modern, contemporary homes
• Strong enough to span larger openings without extra support bars
• Clean finishes with a sleek, architectural look

Roof lanterns from Unique Glazing

Our full range of roof lanterns is designed to give you complete flexibility over the look, feel and performance of your extension. Choose from:

• Materials: uPVC (Liniar Elevate) or aluminium (Korniche)
• Glazing options: self-cleaning glass, tinted solar control glass and high-performance double glazing
• Colours: a variety of finishes to match your home’s existing aesthetic
• U-values as low as 1.1 W/m²K: a U-value measures how well a material keeps heat inside, so the lower the number, the better the insulation and the lower the bills
• A++ energy rated: meaning top-tier energy efficiency

Why trust Unique Glazing?

We’re a family-run business with over two decades of experience installing windows, doors, conservatories, orangeries and roof lanterns across the South East, including London, Slough, Berkshire, Oxfordshire and Surrey. By manufacturing the majority of our products in our own 6,000 sq ft factory, we keep quality high and lead times short.

Our accreditations include FENSA approved installer status, Liniar approved fabricator and installer, GGFi membership and ICO registration. All our roof lantern installations come with a comprehensive insurance-backed 10-year guarantee for total peace of mind.

Ready to bring more natural light into your home? Get in touch with our expert team today on 0800 193 2425 or email sales@uniqueglazing.co.uk for a no-obligation quote. You can also get a quote from filling in our simple form. Our friendly sales team will help you find the right size, style and specification for your project, first time.

Roof Lantern FAQs

Do you need planning permission for a roof lantern?

In most cases, roof lanterns fall under permitted development and don’t require planning permission. However, if you live in a conservation area or a listed building, you’ll likely need approval.

We’re a local installation company who have been installing home improvement products across the capital and beyond for years, so have a real understanding of what’s eligible in our city, something that’s invaluable compared to nationwide chains.

What size roof lantern do I need for my dining room?

As a general rule, your roof lantern should cover around a third of the ceiling area. This brings in plenty of light without overwhelming the functionality of your room or its proportions.

Do roof lanterns need to meet building regulations?

Yes, all roof lantern installations must comply with current building regulations, particularly around thermal performance and structural support. Professional installation by FENSA-approved installers like us ensures everything is signed off correctly.

What is the external kerb size?

The external kerb is the raised frame on your flat roofing that your lantern sits on. The external kerb size determines the perfect fit, so accurate measurements are essential before manufacturing begins.