In brief
A sun tunnel is one of the more modest ways to bring daylight into a room, but there is no single price, because five things set it: the tube diameter, whether the tube is rigid or flexible, how long the run is, what the roof is covered with, and which diffuser sits in the ceiling. We price each job after a survey and send a written quote that lists all of them.
- Tube diameter: a wider tube carries more light and the kit costs more
- Rigid or flexible tube: the two types differ in price, in light delivered and in how they handle bends
- Length: a longer run between roof and ceiling needs more tube and more care at the joints
- Roof covering: tiles, slate and flat roofs each take a different flashing
- Diffuser and extras: the ceiling fitting, and an optional light kit for use after dark
Why a sun tunnel has no fixed price
A sun tunnel looks simple from the landing: a clear dome on the roof, a reflective tube through the loft and a flat diffuser in the ceiling. Underneath, three separate pieces of work are being priced. There is the kit itself, which varies by maker and size. There is the work on the roof, where a hole is cut and a flashing made watertight. And there is the work in the loft and the ceiling below, where the tube is run and the diffuser is fixed and finished.
Two houses can ask for the same kit and still produce different quotes, because the roofs and the loft spaces are different. That is why we do not publish a list of fitted prices. We go up to the roof and into the room, then write down a figure that covers the whole job. Our rooflight costs page sets out how pricing works across every product.
Tube diameter
Sun tunnels are sold in a small range of diameters. A wider tube collects more daylight at the dome and delivers more of it into the room, and the dome, flashing and diffuser all grow with it. The price rises with the diameter, but so does the output, so the choice is really about the room.
A narrow tube suits a small cloakroom or a short landing. A wider one suits a hallway with no window, a kitchen corner or a bathroom of ordinary size. A room with a single tunnel and little else to light it may be better served by the larger option than by a cheaper kit that leaves it dim. We go through the choice at the survey, and how much light a sun tunnel gives explains what decides the output.
Rigid tube or flexible tube
A rigid tube is a smooth, mirror-finished metal section, and it lets light travel with little loss over a straight run. A flexible tube is a ribbed, reflective hose that bends to avoid a rafter, a water tank or a cable run. Each is priced differently, and each has a place.
- Rigid: usually the better choice when the loft is clear and the path from roof to ceiling is straight, and the kit tends to cost more
- Flexible: useful when something is in the way, and it generally costs less, though the ridges lose some light and long runs need to be pulled tight
- Mixed: a rigid section with a short flexible length at one end is a common compromise
If you are weighing the two, rigid or flexible sun tunnel compares them in more detail.
Length of run and the roof it goes through
The tube has to cover the distance from the roof to the ceiling, so a tall loft or a deep roof space needs more tube and more joints, and every joint has to be sealed and taped so the tube stays clean inside. We measure the run on the survey instead of guessing from the outside of the house.
The roof covering decides the flashing. Plain tiles, concrete interlocking tiles and slate each need a flashing that suits their profile, and a flat roof needs an upstand kit dressed into the roof covering. Old or fragile tiles around the opening take more time and care to lift and relay. If your roof is being re-covered anyway, the sun tunnel can go in while the roofer has the covering open, which saves the work of opening it up twice. Flat roofs are covered in sun tunnels in flat roofs.
Diffuser, light kit and finishing
The diffuser is the visible part in the room. Some makers offer a plain flat panel, others a more decorative or domed one, and the finish may be matched to the ceiling or chosen to stand out. These are small price differences compared with the tube, but they are part of the quote.
A light kit adds an electric lamp inside the tunnel so the diffuser can be used as an ordinary ceiling light in the evening. It needs a cable run, which the electrician puts in at first fix, and it is priced as an extra. A plain tunnel gives no light at night, which matters in a windowless hallway. Some owners also want a ceiling lining or a plastered reveal around the diffuser, and where the plasterer is booked anyway, the quote says who finishes the ceiling so nobody is paid twice.
How the quote works
We start with a free survey. We inspect the roof from outside, go into the loft to see the run and any obstructions, and look at the room below. You then receive a written quote that names the kit and its diameter, the type of tube, the flashing for your roof, the diffuser, the build and delivery wait, and anything a builder or roofer on site needs to do.
Where a sun tunnel is part of a larger project, such as a loft conversion or a new roof, we can quote from the plans and confirm on site later. The fitting meets the Building Regulations in force, and we stand behind it with a 10-year workmanship guarantee. For a wider view of the options, the sun tunnels page covers the range.
Related questions
- Does a sun tunnel cost less than a roof window?
- It can, because no structural opening is trimmed and there is no window frame to line. Whether it is the right choice depends on the room, and sun tunnel or skylight explains how to decide.
