How Much Does a Sun Tunnel Cost?

A sun tunnel, also called a tubular skylight, has three parts: a domed collector sitting proud of the tiles, a mirror-finish tube running down through the loft, and a frosted diffuser set into the ceiling below. Because nothing structural is cut away, there is no trimmed opening, no plastering round a large frame and no new reveal to finish. That is why the cost sits below a roof window of the same room.

UK market prices for a fitted tubular skylight typically run from a few hundred pounds at the simple end to somewhat over a thousand where the job is more involved. Treat that as a broad guide from the wider market rather than a quote from us. What lands you at one end or the other is a handful of choices.

Tube diameter matters too. A wider tube carries more daylight, and the collector and flashing cost more as the size goes up.

The longest part of the price story is the run from roof to ceiling. A short drop through a shallow loft needs little tube and one straight length. A tall Victorian terrace, with a landing three floors down, needs more material and often an offset where the tube has to dodge a joist or a water tank.

We look at the route in the loft at the survey. If the tube can run straight, we say so. If it needs an elbow, we show it on the quote as its own line, so you can weigh a slightly dimmer result against the extra cost. Our page on rigid vs flexible sun tunnels explains what each tube does with that bend.

The collector sits on a flashing that has to match your roof. On a plain concrete tile roof that is a routine job. On a Pennant or Bath stone tile roof, or on natural slate, the flashing is worked more slowly and the cost rises with the time it takes. A flat roof uses a different base, which we cover in sun tunnels on a flat roof.

Access plays a part as well. A terrace with a narrow alley and no front space can slow the carry of materials, and a roof that needs a longer scaffold run adds to the sum. Neither is a surprise on the day, because both are noted at the free survey and written into the itemised quote.

Some additions change what the tunnel does, and a few are worth deciding at the start because they are cheaper to fit at the same visit.

• Ventilation kit. Gives a tunnel into a bathroom or landing a way to move air as well as light. See sun tunnel ventilation kits.
• Light kit. A fitting in the tube so the same opening lights the room after dark.
• Insulated diffuser. A sealed lens with a better thermal break, relevant to the heat question in do sun tunnels lose heat.
• Plastering and decorating. A neat ceiling finish round the diffuser, if you want us to include it.

Asking for these on the quote costs nothing, and you can strike any line out.

If the room is in the roof, and you want a view as well as ventilation, a roof window does more, and the extra cost buys a sash that opens. If the room sits in the middle of the house, with no roof slope above it, a sun tunnel reaches places a window cannot. Our comparison of a sun tunnel and a rooflight goes through the decision room by room.

For hallways, landings, windowless bathrooms and dark corridors, the tunnel is often the cost-effective route. For a loft bedroom, it rarely is. You can see how we price the wider range of roof glazing on our costs page, and the full sun tunnel service is described on the sun tunnel installation page.

The work meets current Building Regulations and carries our 10-year workmanship guarantee, and neither is an add-on charged separately later. Every part of the job is itemised, so you can query any line before saying yes. It also helps to photograph the landing or bathroom ceiling and send it over, because we can then tell you roughly how the route might run before we visit.