A Beginner's Guide to Solar Tubes

Published on Wednesday, 5th October 2016

Do you want more natural light in your home or office? Do you have a windowless room in need of natural light or a dark stairwell to brighten? Do you want to add daylight to a room that can't have skylights or vertical windows installed? Find out everything you need to know about buying a sun tunnel.

"According to an 2014 survey, more than 95% of sampled VELUX sun tunnel customers would recommend it to others" Source: VELUX

What Are Sun Tunnels?

Sun tunnels are an ingenious solution to adding daylight to windowless or dark rooms. They channel sunlight from your roof, down a highly reflective tube into the room below. They can be installed on a pitched roof to reach a windowless bathroom or on a flat roof extension to add more daylight to a kitchen extension. You can buy sun tunnels for walls, which will channel light into more difficult spaces such as basements and other underground rooms, as well as other levels of your property.

They are also known by a range of other names, such as tubular or tunnel skylights, solar tubes, sun tubes and daylight tunnels. They all have the same purpose: to add natural light and comfort to your room and reduce the need to use electricity.

What are solar tubes?

"The product was of very good quality and reasonably easy to install. The Lightway Crystal Tubular Skylights Work really well." A happy Sterlingbuild customer

How Do Sun Tunnels Work?

The top part of the installation sits in your roof, opening up a channel for the sunlight.

The sunlight particles bounce off a highly reflective tube that connects the top and bottom of the sun tunnel.

Daylight particles bounce light from the opening in the roof, down the tunnel to the opening in the ceiling below. The more reflective the material and shorter the tunnel's length, the more natural light you'll enjoy.

A diffuser is installed in your ceiling to give a tidy finish to your installation. It will sit seamlessly in your ceiling. You can get obscured plates to softly diffuse the natural light entering your room.

How do solar tubes work?

"Good quality product which has made a big difference to the light in the room." Another happy Sterlingbuild customer who bought a VELUX TWR sun tunnel

How Effective Are Sun Tunnels?

In one word? Very. However, there are some factors you need to take into account:

  • Roof position - Where possible, install your sun tunnel on a south facing roof. This will allow it to harvest the best quality of light. But don't worry, ambient light from north, east or west facing roofs will still make a huge difference
  • Tube length - The higher your roof space, the longer your tunnel, the more light is lost. The best option where possible is a short, rigid tube to ensure you get the most amount of daylight into your room.
  • Obstacles - If you have obstacles in your loft, a flexible tunnel will help you get round them. But because of the tiny creases in the design of the tunnel to make it flexible, light particles are bounced around the tunnel more and so more are lost between the roof and ceiling. However, the amount of natural light you will get will still make a huge difference.

"We had a Lightway light pipe installed for a [customer]. He is very satisfied with the light pipe and was surprised by how brightly it shined." Lightway customer

How Much Daylight Will I Get From a Sun Tunnel?

Even on a cloudy day, a sun tunnel will perform just as well as a single lightbulb. The larger the sun tunnel or the more you install, the more daylight you will enjoy.

The table below shows how a Lightway sun tunnel compared to an average lightbulb used in a home. Lightway is one of the best performing sun tunnels in the UK market so other brands' performance will vary.

Sun Tunnel Size

Equivalent Number of Lightbulbs
Overcast Day Sunny Day
15.5cm Lightbulb How much light does a sun tunnel produce?
23cm How much light does a sun tunnel produce? How much light does a sun tunnel produce?
32cm How much light does a sun tunnel produce? How much light does a sun tunnel produce?
52cm How much light does a sun tunnel produce? How much light does a sun tunnel produce?

How much daylight do you get from a solar tube?

"Not enough exposure to natural light will affect your productivity by disrupting your sleep, increasing your stress levels, reducing your energy levels, and affecting your attention." A Life of Productivity

How Many Sun Tunnels Do I Need?

The more, the better. As with vertical windows and skylights, the more space you give daylight to get into your room, the better the results. We advise you to get the biggest you can for 1 or 2 sun tunnels installed centrally in your room, or a handful of smaller sun tunnels evenly spaced around the room.

This chart shows which sun tunnel size is best suited to a type of room. Again, we use the Lightway sun tunnel as an example. Other brands' performance will vary.

Tunnel Diameter Room Size Room Type  
15.5cm 3-5m2 Small rooms, cupboards and short corridors
23cm 6-9m2 Hallways, small bathrooms or specific area of a larger space
32cm 10-15m2 Large hallways, stairwell and bathrooms
52cm 16-20m2 Kitchens, bedrooms and living rooms


"I have a tubular skylight (brand unknown) in my family room and, even though it would be dramatic to have a couple of venting skylights included in an upcoming kitchen remodel, I love the solar tube and will probably opt for them solely on the basis of cost." Jann Swanson, Sun Tunnels Offer Advantages over Flat Skylights

How Much Do Sun Tunnels Cost?

As with any product, costs vary between quality and brand. We've offer a selection of sun tunnels that meet every budget requirements.

PLUS! We price match so you're always guaranteed the best prices at Sterlingbuild.
AND! We offer a free delivery service.



"[The VELUX sun tunnel was] used in a dark passage way, transformation to the area in natural lighting terms excellent. DIY installation took one day" Sterlingbuild customer


Why not speak to our customer services team to discuss which sun tunnel brand is best for your project and budget? Call them on 01304 219922 today for friendly, expert advice.

Installation costs vary. We know a team of experienced installers who will be happy to give you a quote. To find out more, visit www.roofwindowrepair.co.uk