A roof lantern is a beautiful and functional addition to flat roof extensions, orangeries, and open-plan living spaces. It floods the room below with natural light and creates a sense of height and elegance. But how much does a roof lantern cost to install, and what should you know before going ahead?

This guide breaks down the average prices, installation process, and key things to consider before fitting a roof lantern in your home.

How much does it cost to install a roof lantern?

The total cost of installing a roof lantern varies based on its size, style and whether structural changes are needed. But on average, the supply and installation of a small uPVC roof lantern costs around £1,150.

These prices usually include removing the existing roof section, making structural changes, installing the lantern and sealing it properly. They don’t include interior plastering or painting and decorating afterwards.

Roof lantern brands

Image	Name	Cost
	Wendland 750mm x 750mm uPVC Roof Lantern	£524.56
	Alutherm 700mm x 700mm Pyramid Aluminium Lantern	£699.42
	Korniche 850mm x 850mm Aluminium Roof Lantern	£775.37
	Titan Slimline 1000mm x 1000mm Aluminium Roof Lantern	£795.00
	Brett Martin 1500mm x 1000mm Contemporary 4 Panel Aluminium Roof Lantern	£1105.43
	Thermalight 1000mm x 1500mm Aluminium Roof Lantern	£2325.00

Factors affecting the cost of roof lantern installation

There are lots of factors that can affect the cost of roof lantern installation, so it’s important to consider them before you go ahead. Factors include size and shape, material and where you want the roof lantern installed:

• Size and shape: Roof lanterns vary hugely in size and shape, and therefore price. For example, a small uPVC roof lantern can cost as little as £550, but a very large 6000mm x 3000mm one could set you back nearly £4,000.
• Material: Aluminium frames are pricier than uPVC but offer a sleeker, stronger finish and are often more thermally efficient.
• Glazing: Double vs triple glazing, low-emissivity (low-E) coatings, and solar control glass all affect the overall cost.
• Access: If your roofer needs scaffolding to access your roof for installation, expect to pay an additional £400 or more.
• Condition of roof: Older or non-standard roofs may need reinforcement or redesign to support a lantern, and on inspection you may find you need to replace your flat 
• roof before work can start.
• Optional extras: Adding trickle vents can cost around £40 each, while automatic openers or roof finials can add an extra £300.
• Finishing touches: Internal plastering and painting and decorating can add £300-£1,000, depending on the finish.
• Your location: Where you live can have a big impact. Roofer rates tend to be highest in London and the south east and lower in the north.

At HaMuch, we use our database of hourly and daily rates for roofers across the UK to estimate how much jobs cost in your local area. Take a look at our roof lantern installation cost table and find your nearest town or city to get a better idea of how much your project will cost.

Advantages and disadvantages of roof lanterns

Roof lanterns are sometimes called skylights. They’re designed to increase the natural light in your home by creating a glass opening in your roof. 

They are often pyramid-shaped and extend above the roofline, so they create a lovely focal point on flat roofs. However, they can be installed on pitched roofs in some circumstances.

Like anything, there are advantages and disadvantages to roof lanterns. Let’s take a closer look:

Advantages

• Increases natural light: Brings significantly more daylight into your home than traditional windows.
• Aesthetic impact: Adds a contemporary, luxury look both in and outside your home and creates a dramatic focal point in open-plan spaces.
• Energy efficiency: High-performance glazing helps retain heat in winter and reflect solar gain in summer.
• Improved ventilation: Some models can open to help regulate temperature and airflow.
• Perception of space: Makes rooms feel taller and more spacious.

Disadvantages

• Cost: Large roof lanterns can be expensive, running into the thousands of pounds.
• Cleaning: You’ll probably need a professional cleaner to help you clean the outside glass as your rooflight will be difficult to access.
• Heat gain/loss: Poorly installed or insulated lanterns can lead to thermal inefficiency, although most modern units are energy efficient.

Only you can decide whether a roof lantern is right for you. Weigh up the pros and cons and consider getting quotes from roofers before making your final decision. 

What's the difference between a roof lantern and a skylight?

Roof lanterns and skylights are similar as they both allow more light into your home. However, they have some key differences:

Which type is best for you depends on where you want to have it installed, your budget and whether you want the roof window to be a focal point or blend in with your home. 

How long does it take to install a roof lantern?

How long it takes to install a roof lantern depends on the size of your roof and how many structural changes need to be made. But a straightforward installation of a small roof lantern usually takes less than 1 day.

If your roof lantern is very large or you need more structural reinforcements to your roof, it could take 2-3 days to complete.

Once the installation is done, plastering and finishing the ceiling and redecorating can take 1-2 days, plus time to allow any plaster to dry.

Roof lantern installation process

Here’s a typical step-by-step breakdown of how roof lanterns are installed on flat roofs:

1. Site assessment: Your roof will check the roof structure, access and suitability for a roof lantern, then measure up so you can decide on the size roof lantern you would like. This will then be ordered; most take around 4 weeks to be made to order and delivered.
2. Opening prepared: Your roofer will cut away a section of your flat roof and strengthen it if needed. Usually the aperture is exactly the same size as the roof lantern, and the width should be the same as the upstand that comes with the lantern.
3. Weatherproofing: The roofer should leave enough roof felt or membrane around the timber curb and upstand if it’s already there. If not, they should fit the membrane after the roof lantern has been installed.
4. Upstand assembly: The roof lantern is usually delivered flat-packed. The upstand may be ready-assembled, but large roof lanterns may need to have the upstand built on site.
5. Installation and sealing: The roofer will fix the frame onto the curb using professional silicone. They install the hip bars next, followed by the ridge bars that go across the middle of the lantern. Then it’s time to fit the glass panels, using silicone to fix into place, and then add hip carriers, ridge carriers and top caps to finish the lantern.
6. Add roof membrane: If not already present, your roofer will finish the installation by adding a roof membrane to the roof lantern’s upstand to weatherproof it.

Always ensure your installer is experienced and provides the right guarantees for the work and materials. Many installers can give up a 20-year guarantee.

Can you get roof lanterns that open?

Yes, many roof lanterns come with ventilation panels that can open manually or via an electric motor. Options include:

• Manually opening vents, which are operated with a winding handle or pole
• Electric vents, which are controlled by a switch or remote, with optional rain sensors.
• Automated systems, which have temperature and moisture sensors that can integrate with smart home systems.

Ventilation can help reduce condensation and prevent overheating in summer, especially in kitchens or south-facing rooms.

Do you need planning permission and building regulations to install a roof lantern?

In most cases, you don’t need planning permission for a roof lantern, as they fall under permitted development rights. But there are exceptions:

• The lantern must not project more than 150mm above the existing roof plane
• It must not be higher than the highest part of the roof
• Your home must not be in a conservation area or a listed building 

Even if planning permission isn’t required, building regulations approval is. This ensures structural safety, insulation, and fire performance. Your installer or builder should handle this and provide a certificate once work is complete.

Do roof lanterns add value to your home?

Yes, a well-installed roof lantern can increase your home’s value by enhancing natural light and improving the aesthetic appeal of open-plan living areas. Estate agents often view roof lanterns as a desirable feature, particularly in kitchen-diners and garden rooms.

The increased sense of space, light and luxury can make your home more appealing to buyers and help justify higher asking prices. However, we always recommend considering the value a roof lantern will add to your quality of life, as there’s never any guarantee that you’ll get your money back on added value to your home.

Looking to transform your home with a roof lantern? Post your job on HaMuch and connect with experienced local installers who are ready to help you bring more light into your home.

^*Image of Aspekt Lantern Rooflights from Renka

Estimates for common roofer jobs;

Rates for other trades