When Should you Choose a Light Tunnel over a Rooflight?

The popularity of Light tunnels has skyrocketed in recent years as homemakers recognise their practical and economical ability to transform those harder to naturally light areas of the home.

By Larry Bohan on 7 Jul 2019

sterlingbuild sun tunnel external view

So you’re doing up the home. Making it bigger, airier and naturally brighter throughout. But then you come to the hallway, bathroom and stairs.

The absence of outside walls make the installation of windows in certain places impossible. But that's doesn't mean daylighting is not possible. There is light at the end of the tunnel…literally. 

Light tunnels are an ideal solution to brightening up windowless rooms without having to resort to artificial lighting.

But it’s not just windowless rooms light tunnels can enhance.

Sterlingbuild’s new light tunnels come in three sizes to suit any room from 4m2 to 25m2, be it kitchen, living room or bathroom.

But when are light tunnels a better daylighting option to roof windows? Here’s all you need to know, starting with price.


Overall, light tunnels are cheaper to buy than traditional flat glass rooflights.

Light tunnels are also designed to convey light into a building with greater efficiency versus conventional skylights, making them more than just an economical choice for renovations.

All Sterlingbuild branded sun tunnels come in tube lengths of 3m. These can be cut to 2m for greater light transmission or extended, which will reduce light. Naturally, the bigger the diameter of the tube, the higher the price.

As with roof windows, SB light tunnels have zero running costs. This guarantees a noticeable reduction in electricity bills during daytime hours, as well as a reduction to your carbon footprint.

 sterlingbuild light tunnel installed in dining room


how to sterlingbuild sun tunnels work


As already mentioned, light tunnels are often the only source of natural light available to windowless rooms, filtering sunlight in from the roof space, down the highly reflective tube and finally through the diffuser fitted to the ceiling.

Most rooflights don't go much lower than 47x98cm in dimension, making sun tunnels sometimes the only appropriately sized daylight option too.

The low-key internal appearance of light tunnels is far less pronounced than with rooflights, taking up less of the ceiling area to the advantage of certain room layouts.

Externally, the low profile of sun tunnels, available from Sterlingbuild for slate or tile roofs, is preferred by many for the way the covers seamlessly sit atop the roof. Light tunnels are also undoubtedly less of a security, safety or privacy concern.

To find out more about sun tunnels, including information on best positioning, covers and quantity recommendations, check out our Sun Tunnel Buying Guide.


Thermal Control

Due to the size of the units and nature of their design, less heat loss will occur with sky tunnels than with rooflights.

On top of this, all Sterlingbuild sun tunnels come with an adjustable ventilation option that can help bring fresh air down from the tube.

Although the technological advances in glazing that have occurred in the roof window industry cannot be deemed anything but a good thing, traditional skylights can unwantedly increase temperatures.

With SB light tunnels, minimal heat will ever enter through the tunnel as the unit is double glazed at ceiling level. The dome at roof level also reduces heat transmittance and none of the tubing components hold heat.

Sterlingbuild sun tunnel installed in dining room