Question · Roof Lanterns
How Much Does a Roof Lantern Cost?
The short answer
A roof lantern typically costs from the low thousands of pounds for a small, standard lantern to well into five figures for a large, bespoke or opening one, supplied and fitted. The size, the frame material, the glass and the state of the roof beneath decide where a job lands in that range. Only a survey can turn a market range into a figure for your roof.
Where lantern prices sit
Lantern rooflight prices are wide because no two roofs ask for the same thing. As a broad UK market guide, a small lantern in a standard size typically costs somewhere in the low thousands of pounds once supplied and fitted. A mid-sized lantern over a kitchen extension typically sits well above that. Large, made-to-measure lanterns, particularly in timber or with several opening vents, can climb into five figures.
Those are market ranges, not our prices. Every figure depends on the points below, and a lantern priced for a neighbour's roof says little about yours. Our costs guide covers rooflight pricing across the whole range, from a single roof window to a full set of lanterns.
A useful habit is to ask for a price per square metre of glass from any supplier, then check it against the whole job. The glass is only one line. Delivery, lifting a large lantern onto a roof and the labour to set it level all sit beside it. A lantern that arrives in sections and is assembled on the roof costs differently from one built as a single unit and craned in, and the access to your garden decides which is practical.
What moves the price
Five things do most of the work. Start with the footprint: a lantern is a small glass building, so a longer and wider one needs more frame, more glass and a stronger upstand beneath it. Sizes and proportions are laid out in the guide to roof lantern sizes.
| Factor | Effect on the quote |
|---|---|
| Frame material | Aluminium is usually the lower cost. Timber and bespoke finishes cost more. |
| Glass | Higher-performance, self-cleaning or tinted glass adds to the price. |
| Opening vents | Each motorised or manual vent adds hardware and wiring. |
| The roof beneath | A new upstand or a reworked roof adds labour. |
| Access | Tight sites and lifting needs add time. |
The frame choice is worth its own look. Our comparison of aluminium and timber roof lanterns sets out what each costs you in upkeep as well as at the start.
Opening vents and glass options
A fixed lantern is the simplest build. Adding a vent that opens means a hinged sash, a handle or motor, and a seal that closes tight in rain. It is also what turns a bright room into one you can air on a warm morning, so many owners find the extra worth it. The opening roof lantern page explains the vent types.
Glass is the other lever. Standard double glazing with a low-emissivity coating suits many extensions. Solar-control glass costs more, and is the sensible spend on a south-facing roof. The heat side of that trade is covered in roof lantern overheating. Laminated inner panes are a recommendation, never a legal requirement for a house roof, and they too add to the price.
Cheaper glass always saves money overall.
A lantern that overheats or glares in summer can cost more to live with than the glass upgrade would have cost to fit.
Colour is another small line. A standard white or grey finish sits in the base price. A custom colour, or a different shade outside from the one inside, adds a charge because the frame is finished to order. Ask whether the quote assumes the standard finish.
Costs beyond the lantern itself
A lantern is only part of the job. The roof below it may need work first. If an existing flat roof has no upstand, or the timbers cannot carry the added weight, the quote will include that. The checks for fitting a lantern over a flat roof you already have are set out in a separate answer.
A fresh opening in a roof counts as building work, so the timbers around the hole are framed to carry the load and the finished job has to comply. When a whole unit is swapped, glass and frame together, the work is notifiable, and we handle the Building Control notification where the work is notifiable. How the fee and paperwork work is explained under roof lantern building regulations.
Internal finishing is usually separate from the lantern price: plastering the new lining of the opening, decorating, and any scaffold if the roof edge needs one. Ask what a quote includes and leaves out.
Reading a quote properly
The survey costs nothing, and the written quote carries no obligation. Itemised means the lantern, the roof work, the finishing and any fees on separate lines, so you can compare like with like. Opening options are shown on every quote, which lets you see what a vent adds before deciding.
When you compare quotes, check that each one covers the same frame, the same glass and the same number of vents. A low figure that quietly leaves out the upstand or the opening hardware is not a saving. Check also how the roof is protected while the old covering is open: on our jobs, one team does the work and makes the roof weathertight at the end of every day. A 10-year workmanship guarantee comes with the installation, and the details are on our guarantee page.
For a wider view of the lantern range, start from the main roof lantern installation page.
Pricing a lantern for your own roof
Is a roof lantern cheaper than building a pitched roof over an extension?
It depends on the design. A lantern sits in a flat roof that is already needed, so it adds glass and light without replacing the roof. A fully glazed pitched build is a different project with different costs. A survey shows which suits the extension.
Can I spread the cost by fitting the lantern now and adding vents later?
Sometimes, but the frame is usually made for its vents from the start. Adding opening sashes afterwards may not be possible on every design, so decide at the quote stage and ask us to price both.
Tell us about the room
A few details is all we need. We'll come out, advise and give you a written quote.
No pressure, no obligation.