Roof Lantern Size Guide

Roof lanterns are the perfect way to brighten up your interior and add more character to your space. The number of roof lantern sizes available can make the process overwhelming, but choosing the right size for your roof is easier than you might think. Ultimately, it comes down to 3 key factors: 

• Roof structure
• Room orientation
• Room size

Considerations For Roof Lantern Sizes

1. Structural Compatibility

Ensure your roof can support the lantern's size and weight. The structural integrity of your home is the single most important thing, so consult with professionals to determine the appropriate size that your roof structure can accommodate without compromising safety.

2. Room Orientation and Light Exposure

Consider the direction your room faces. South-facing rooms naturally get more sunlight, potentially reducing the need for a large roof lantern. On the other hand, north-facing rooms benefit from larger lanterns to maximise the lesser available natural light.

3. Room Size and Proportion

The size of the room is important for determining the appropriate roof lantern size. A large lantern in a small room can overwhelm the space, while a small lantern might not provide enough light in a larger room. Aim for a balanced proportion to enhance the room's look and functionality.

Additional Considerations 

Privacy is another important factor, especially in areas that can be seen from the surrounding environment (houses, hills etc.). While blinds can be used to minimise this, a large roof lantern might compromise privacy if positioned without thought, so consider the placement and size of the lantern to keep it secluded.

Daylight Systems by Brett Martin Roof Lantern Size Chart

We have a range of styles, from 6-panel lanterns with a traditional feel to contemporary 4-panel designs. With white and grey interior colour options, you can find the right lantern to suit your decor. Clear glazing maximises the intake of light, while blue-tinted glazing provides solar control. The table below shows the standard sizes available. If you can’t find your perfect fit here, you can choose custom sizing for our bespoke roof lanterns.

Do You Need Planning Permission For a Roof Lantern?

You don't typically need planning permission to add a roof lantern to your property. However, it's essential to comply with local development rules to ensure your new roof window meets the necessary regulations. Here are the key rules to keep in mind:

• The roof lantern should not protrude more than 150 mm above the existing roof.
• The peak of the roof lantern must not surpass the roof's highest point.
• When positioned on a side-facing roof slope, the roof lantern must feature frosted or opaque glass.
• Roof openings are permissible only if they are situated at least 1.7 meters above the room's floor level.

How Much Does a Roof Lantern Cost?

In the UK, the price of a roof lantern can vary significantly,  from £500 to £3000. This comes down to three main factors:

• Size - More materials and labour mean more cost
• Type - Units with more panels tend to be more expensive
• Features - Additional features like tinted glass add to the price

Beyond the basic type and size, the features you select can also impact the price. Options such as interior colour, glazing type—clear or blue-tinted—and additional features like self-cleaning glass or integrated blinds will influence the final cost. Installation is another thing to consider. If your lantern is going to be professionally installed, you’ll need to consider this when budgeting.

How to Install a Roof Lantern

Our roof lanterns allow for self-installation, thanks to their forward-thinking design. If you’re not big on DIY, you can always hire a professional installer.

Here's a quick step-by-step guide to the installation process:

1. Assemble base frame
2. Apply sealant then rotate and position the frame on an upstand
3. Connect spider frame
4. Fit spider frame to base frame
5. Fix unit to upstand through pre-drilled holes
6. Prepare glass
7. Fit glass to the frame and align corners
8. Position glazing clamps
9. Align and clip on hip outers
10. Align and clip on ridge outers then fix down glazing clamps
11. Clip-on ridge caps
12. Attach hip caps
13. Attach rafter caps (6-pane option only)

Key Takeaways

Here are the main things to keep in mind when considering roof lantern sizes:

• Before anything else, ensure your structure can withstand a roof lantern installation

• Familiarise yourself with local regulations before carrying out any work

• Size is one of the biggest determining factors of the cost

• Consider room orientation, size and proportions to choose the perfect size for your space

Frequently Asked Questions

What sizes do roof lanterns come in?

Roof lanterns are available in a wide range of sizes to suit different spaces, from compact options of 1500 x 1000 mm for smaller areas to large, expansive 3000 x 2000 mm designs for bigger spaces. Our bespoke roof lanterns allow you to choose your own custom size, ensuring there's a roof lantern to fit almost any flat roof.

How are roof lanterns measured?

Roof lanterns are measured by their external frame dimensions, which include the width and length of the lantern. It's crucial to get accurate measurements to ensure a perfect fit with your roof opening.

Can a roof lantern be too big?

Yes, a roof lantern can be too big if it overwhelms the room or exceeds the structural limits of the roof. It's important to choose a size that complements the scale of the space and maintains the integrity of the building.

Do I need permission for a roof lantern?

Generally, you don't need planning permission for a roof lantern unless your property is listed or in a conservation area. However, it's always best to check with your local planning authority to ensure compliance with local regulations.

Can you add a roof lantern to an existing roof?

Yes, you can add a roof lantern to an existing roof, providing that the structure can support the additional weight and alterations. It's a popular way to bring more natural light into a space without the need for extensive renovations.