Flat roof window or roof lantern: which suits you?

What is a flat roof window?

A flat roof window, sometimes called a flat rooflight, is a flat or slightly pitched glazed unit on an upstand. It is usually made in fixed standard sizes, and those sizes are modest, similar to a rooflight dome. Many models open, by hand or electrically.

Its strength is its size. A roof window is quickly fitted into an existing opening and brings light and fresh air to places with little space. Think of a bathroom, a walk-in wardrobe, a stairwell or a landing. A large strip of glass is not needed there.

What a roof lantern in a flat roof does differently

A roof lantern is an elongated strip of glass in an aluminium frame. Where a roof window gives a patch of light, a roof lantern spreads daylight along the full length of the room. That also brightens the back of a deep extension or a dark middle room.

DagLichtDesign makes roof lanterns for flat roofs in four roof types: mono-pitch, wall-abutting lean-to, gable and hipped. The aluminium frame comes in any RAL colour, with HR++ double glazing as standard. Triple glazing is an option. The roof lantern is made to measure for your roof, so you are not tied to a standard size. For most extensions a mono-pitch is the logical choice, with a standard pitch of 8° for quick drainage.

• Daylight along the full length of the room
• Made to measure in length and width
• HR++ double glazing as standard, triple optional
• Aluminium frame in any RAL colour

Flat roof window or roof lantern: how to choose

Start with the floor area. For a few square metres, a flat roof window or rooflight gives enough light. For a living room, open kitchen or an extension several metres deep, one small window will not do. A roof lantern over a larger part of the roof will.

Then look at ventilation. A separate roof window often opens. A roof lantern has no moving parts, so fresh air then comes through a window or vent in the wall. Still torn between dome, window and strip? Roof lantern or rooflight dome will help you decide.

• Small room or stairwell: roof window
• Living room, kitchen or extension: roof lantern
• A window that has to open: roof window
• Existing hole in the roof: measure the opening precisely

Costs and an existing roof

A roof lantern costs more than a small roof window, because you get much more glass and frame. What drives the price is explained in what a roof lantern costs. If you already have a flat roof, a roof lantern can usually be fitted, provided the structure allows it. How that works is covered in a roof lantern in an existing flat roof.

Frequently asked questions