Let there be light! How a VELUX sun tunnel will benefit your home

What is a VELUX sun tunnel

Also known as a VELUX sun tube or VELUX sun pipe, a VELUX sun tunnel is a 4mm toughened glass window that reflects light down either a flexible or rigid sheet metal tube that has a polished interior. They work like a mirror, preserving the intensity of the light and channelling it to where you need it most. 

The positive benefits of VELUX sun tunnels

These tubular skylights bring daylight into windowless or dimly lit rooms. In two storey houses, natural daylight is often missing on landings and bathrooms. Bungalows with dimly lit areas like hallways also really benefit.

Other advantages:

  • Easy to install into all types of roof.
  • Daylight gives a sense of additional space.
  • Natural daylight harvesting – harnessing this sustainable natural source of energy - it’s totally free and also completely environmentally friendly.
  • You can take advantage of moonlight – a sun tunnel puts you in touch with the outside environment.
  • The attractive flat plate - is preferred when there is a planning constraint (i.e. in conservation areas or on the roof of a Listed Building) or if you just don’t like the idea of a flat roof dome from an aesthetic point of view.

There’s a VELUX sun tunnel for every location 

You can add a VELUX sun tube anywhere there is 6 metres or less between your roof and the ceiling. They are suitable for both flat or pitched roofs and don’t take up too much space. 

Light is channelled through your loft and into any interior room, hallway, walk in wardrobe, or bathroom. You can’t restrict the amount of light through the tunnel, so they aren’t suitable for bedrooms. But quite simply any room should be able to get some natural light (without any huge renovation) and turned into a beautifully light, welcoming space in a matter of hours. 

Improvements in design and installation

If you’ve had a VELUX sun tunnel before, you’ll be aware just how easy they are to install and the benefits they provide, but significant improvements to the design include:

  • They can now be assembled in half the time, thanks to the new Flexi-Loc system. 
  • There’s no need to enter the attic or loft space with the new roof module.
  • Even easier to install and clean. With the new threaded pane you simply screw the diffused pane into place and it can be unscrewed and cleaned as needed.
  • The new VELUX sun tunnel diffuser pane comes with EdgeGlow – a ring of clear polycarbonate that offers spectacular light effects. Edge glow gives a better spread of daylight throughout the room.

Where to position of your VELUX sun tunnel:


  • Where possible, place it where you can bounce light off nearby walls or mirror 
  • Don’t forget to angle the aperture in the ceiling to fill a space much bigger than your opening.


Pitched roof 

  • The sun rises in the east and sets in the west, and the south side of any house will see the most hours of sunlight during the day.  We all know south facing gardens are sun traps, and positioning a sun tunnel in the south facing side of your roof means you will be able to take advantage of the most available amount of daylight. 
  • Similarly, aim to install it as close to the roof’s apex to maximise light: ambient light from north, east, or west facing roofs will still make a huge difference.

Flat roof sun tunnels are available in rigid and flexible, and come supplied with a PVC kerb and polycarbonate roof dome. 

Rigid sun tunnel

  • Deliver a straight shaft of light for when the ceiling is placed directly under the exterior window.
  • For tunnel lengths from 0.9 to 6 m between the roof and ceiling.
  • The 1.7m long rigid tunnel can be used in combination with ZTR extension section.

Velux ZTR extension

when greater lengths are necessary. It is supplied with 2 x 45° bends.

  • Can be extended to distances up to 6 m.
  • The rigid tunnels has a diameter of either 35 cm or 25 cm.


Flexible sun tunnel

  • Flexible tunnels can be used when the distance between the roof and the ceiling is too small for a rigid tunnel.  
  • 0.9 to 2m between the roof and ceiling.

The 2-meter long, super reflective, flexible tunnel has a diameter of 35 cm.

It’s important to note that the further the sun tunnel comes down into the property, the further the light will have to travel and the less light you will achieve. Wherever possible, a rigid tunnel is preferable as the flexible tunnel can have deviations and inevitably you do lose a little light where a bend is required. 

VELUX Sun Tunnel Light Kit

You can now turn on your VELUX sun tunnel at night with a low energy light kit. The kit, which requires mains connection, fits both 10" and 14" rigid and flexible sun tunnels. The low energy LED technology provides a long lifetime of dependable light (approx. 18 years), while the slim line design eliminates shadows on the diffuser pane. 

How much light will I gain, which type and how many VELUX sun tunnels do I need?

The VELUX LUX calculator will help you find the perfect tunnel(s) to match your requirements. After inputting your location on their interactive map, enter a few details about your home and the room your VELUX sun tunnel will be going in. You’ll get a recommendation for which type of sun tunnel will suit, and how many you’ll require to lighten up the room. 

Finding the correct sun tunnel code:

See our range online, and if you need any further help use our LiveChat function to speak to one of our experts.