A roof lantern is one of the best ways to bring daylight into the middle of a flat roof extension, but there are a few choices to get right first. Size, shape, glazing and colour all change how the finished room looks and feels. It is tempting to chase the best online windows and doors bargain, but a lantern rewards a bit of thought and a proper measure. Here is how to choose one you will be glad of for years.
Match the size to the room
Size is the choice that matters most. A lantern that is too small looks lost on the roof and barely lifts the light, while one that is too big can overheat the room and dominate the view from the garden. As a rough guide, aim for a lantern covering around a quarter to a third of the flat roof area, then adjust for the shape of the room below.
Think about proportion too. A long, narrow kitchen suits a long rectangular lantern, while a square room carries a square design well.
Pick a shape and pitch
Most lanterns are rectangular or square, with the glass sloping up to a ridge. A few things to weigh:
- Pitch: a steeper pitch feels grander and sheds rain well, but adds height and cost
- Ridge style: a slim ridge gives a cleaner, more modern look
- Bars: fewer, thinner glazing bars mean more glass and more light
For a contemporary home, a low pitch with slim bars looks crisp. For a more traditional feel, a steeper pitch suits better.
Choose the glazing
Because a lantern is glass overhead, the glazing spec really matters for comfort. Look for energy efficient double or triple glazing with a low U-value, a solar control coating to keep summer heat and glare down, and self-cleaning glass so you are not up a ladder cleaning it. Toughened or laminated safety glass is standard for overhead use. Spend here and the room stays comfortable all year.
Frame material and colour
Aluminium is the popular choice for roof lanterns thanks to its strength and slim frames, which let in more glass than bulkier materials. It also takes colour beautifully. Anthracite grey remains a firm favourite in 2026, black gives a sharp modern edge, and white keeps things classic. Pick a colour that ties in with your windows and doors so the whole extension feels considered.
Our roof lanterns and flat roof lights come in a wide colour range, and if you want the frames to match the rest of the house, our aluminium sliding and bi-fold doors sit nicely under a lantern in the same finish.
Think about the room below
A lantern changes how a room works, so picture the finished space. Over a kitchen island it throws light right where you prep and cook. Over a dining table it makes meals feel brighter and more open. If the room doubles as a home office, lean towards solar control and maybe a slightly smaller lantern to keep glare off screens.
Fitting matters as much as the lantern
Even the finest lantern leaks if the upstand and flashings are poor. The kerb it sits on needs to be square, insulated and sealed properly. This is why a local survey and fit beats an online box every time. Ask who builds the upstand and how the joints are sealed before you commit.
Rough 2026 prices
Prices vary with size, glazing and colour, so treat these as broad 2026 guides. A supplied only aluminium lantern often runs around 800 to 2,500 pounds, while supplied and fitted with a proper upstand typically lands around 2,000 to 5,000 pounds or more for larger sizes. For a figure based on your roof, request a free quote and we will survey it.
FAQs
What is the best roof lantern material?
Aluminium is the usual pick because it is strong, has slim frames and lets in more glass than uPVC. It also comes in a wide colour range. uPVC can cost less but has chunkier frames and less light.
What colour roof lantern should I choose?
Anthracite grey is the most popular in 2026, with black for a sharp modern look and white for a classic feel. The tidiest result comes from matching the lantern to your windows and doors.
How much light does a roof lantern add?
A good deal more than the flat roof alone, because it gathers daylight from several angles and drops it into the centre of the room. The larger the lantern, within reason, the brighter the space.
Do I need building regulations for a roof lantern?
Adding or changing a lantern can bring Building Regulations into play, especially on the structure and glazing. Rules vary, so check the current requirements with your local authority or ask your installer to confirm.
Want to see the shapes and colours in full? Download our latest brochure, or request a free quote and we will pop out for a look.