How much does a sun tunnel cost?

Of the three parts, the tube changes most from one job to the next. A landing under a pitched roof may need a short, straight drop between two joists. A hall in the middle of a bungalow may need a long run with bends, and every extra length and elbow adds material and fitting.

Rigid or flexible is the next choice. Rigid tube comes in straight lengths with elbows to turn corners, and flexible tube can bend round obstacles at some cost in light. Our page on rigid or flexible sun tunnels sets the two side by side, and the survey decides which one the loft allows.

Width counts as well. A wider tube suits a larger room that needs more light, and more than one width is on offer. The dome has to fit between the rafters and the diffuser between the ceiling joists, so the gap in the structure usually caps what is possible before taste comes into it.

Two rooms that both need light mean a choice. One long run to serve both loses light along the way, while two shorter tunnels are two domes, two tubes and two openings in the ceiling, and they are priced as two jobs.

A pitched roof asks for a flashing that laps with the tiles or slates, so that water runs over every joint. A flat roof asks for a kerb and a covering dressed up to it. Neither is the same job as the other, and neither can be judged without climbing up to see the roof.

The covering around the dome deserves a close look, because a new dome set into a tired roof only moves the problem. If the survey finds a covering that needs attention near the opening, that changes the scope, and it is better to learn so before the quote than after it.

Access plays a part too. A dome and a bundle of tube have to reach the roof and the loft by some route, and a house tucked behind others in a terrace asks more of that route than one with a drive beside it.

The roof space is rarely empty. Joists, rafters, pipes, cables, a tank and loft insulation all compete for the same gap, and the tube has to find a clear route through them. A rafter may need trimming, or the tube may need to bend round a pipe run that cannot move.

At the bottom of the tube, the diffuser needs a round opening in the ceiling between the joists. Where the loft floor is insulated, the new opening should leave that insulation working. All of this is cost in time and materials, and none of it can be read off the room from below.

Our Wales regulation sources do not say whether a sun tunnel dome is treated like a rooflight under the Class C permitted development rules, so we check that with the council for your house. If it is treated that way, a dome on a house can be permitted development where it stands no more than 150 mm proud of the original roof slope and no higher than the highest part of the original roof, and inside a conservation area, the Gower AONB, Bannau Brycheiniog National Park or a World Heritage Site it would need a planning application. Flats have no householder permitted development rights. A listed house also needs listed building consent where the work affects its character, applied for through the local planning authority. The council charges a fee for an application, which belongs in the budget beside the sun tunnel itself.

The Welsh Government sets the rules out in full in its guidance on planning permission for roofs. Where the work is notifiable, we handle the Building Regulations notification with local authority building control or a registered building control approver.

Run, roof, loft and ceiling can only be judged on site. A price quoted from a photograph would be a guess at all four. We survey for free, look at the room and the roof space together, and put a fixed written quote in your hands afterwards. The finished sun tunnel is covered by our 10-year workmanship guarantee, given in writing.

If you are still deciding where one should go, see which rooms suit a sun tunnel best. The wider range is on the sun tunnels page. To arrange the survey, phone 01792 929062 or use the booking form.