Which kitchens gain the most
A sun tunnel, or tubular skylight, pays off in the kitchen that has a window at one end and a gloomy far end where you actually prepare food.
Cambridge has a lot of these. In the Victorian and Edwardian terraces of Romsey, Petersfield and off Mill Road, the kitchen often sits in the middle room or the narrow back addition, with a single window looking onto a side return or a neighbour's wall. The worktop against the party wall can need the lights on at noon in March. A 1930s semi in Cherry Hinton tends to have a small rear kitchen with the sink under the window and a run of units on the opposite wall that sits in shadow. Bungalows in the villages are another good fit, because the kitchen is often in the middle of a deep plan with only a short loft space above it.
What these kitchens share is a dark zone that is only a few metres from daylight but never gets any. A sun tunnel puts a disc of daylight into that zone. It will not give you a view of the sky and it will not make a small kitchen feel like a garden room, but it can change a corner from "lights on all day" to "lights on after four". For the wider picture of where a tube beats a glazed opening, our sun tunnel versus skylight guide compares the two room by room.
Placing it over the island, the worktop or the corner
The diffuser throws most of its light downward in a broad pool, so the right spot is directly above the surface you want lit, not the middle of the ceiling by habit.
In a kitchen that usually means one of three places. Over an island or a peninsula, a tube centred on the worktop lights the chopping area and the stools around it. Over a galley run, placing it slightly forward of the wall units, above the front edge of the worktop, stops the cabinets casting a shadow onto your hands. In an L-shaped kitchen, the internal corner is often the darkest point, and a tube just off that corner reaches both runs. The ceiling position is then fixed by what is above it: joists, the loft or upstairs floor, and the roof slope. We walk through that on the day of the light survey, because a position 300 mm to one side can avoid cutting a joist altogether.
| Kitchen area | Diffuser position | Watch for |
|---|---|---|
| Island | Centred over the worktop | Pendant lights clashing |
| Galley run | Above the worktop's front edge | Wall-unit shadow |
| L-shaped corner | Just off the internal corner | Tall larder units |
| Hob and range | Not directly above | Heat, steam and grease |
Existing lighting matters too. Downlighters, a pendant track or a cooker hood duct may already occupy the ideal spot, and it is easier to move a downlighter than to bend a tube around it. Each bend and each extra metre costs some light, as our guide to tube length and bends explains, so a straight drop is worth planning for.
Steam, grease and the diffuser
A kitchen is a humid room, so the diffuser should sit away from the hob and the room needs extraction that actually clears the steam.
Cooking releases warm, wet air and a fine film of grease. Directly over the hob, that air rises straight into the diffuser, where grease dulls the surface over time and moisture can travel into the tube. Keeping the diffuser a sensible distance from the cooking zone, and letting the cooker hood do its job, avoids both. Most tubular skylight kits use a sealed diffuser, often with a second inner pane, which helps keep room air out of the tube; exactly how each product seals varies, so we specify it for the room rather than assume.
The bigger risk is condensation where the tube crosses a cold loft. Warm kitchen air meeting a cold section of tube can leave droplets, which is why the tube is insulated through the loft and every joint sealed. Our answer on whether sun tunnels cause condensation covers this in detail. The diffuser itself only needs an occasional wipe with a soft cloth and mild washing-up liquid, the same as a glass light fitting.
What the roof above the kitchen has to allow
The tube needs a route from a clear stretch of roof to the kitchen ceiling, and the length and angle of that route decide how much daylight arrives.
A single-storey kitchen, such as a rear extension or a bungalow, is the easy case: a short drop from the roof through a shallow loft or a flat-roof deck. On a flat roof the tube rises through a kerb or upstand, covered in our guide to sun tunnels for flat roofs. On a pitched roof it passes through a flashing kit set into the tiles or slates, then down through the loft.
A kitchen on the ground floor of a two-storey house is harder. The tube has to pass through the first floor, usually inside a boxed-in cupboard, a wardrobe or the corner of a landing, before it reaches the kitchen ceiling. That can work well, but it is a longer run and it takes space upstairs. We explain the options in can a sun tunnel go through two floors.
The slope the dome sits on matters as well. Cambridge is flat, so the dome sees almost the whole sky with no hills to shade it. At midwinter noon the sun is only about 14 degrees above the horizon here, and at midsummer noon it climbs to about 61 degrees. A dome on a south or west slope catches more direct sun in winter afternoons; a north slope still gathers useful diffuse skylight. Our guide to where to put a sun tunnel on the roof shows how to pick the spot.
When a rooflight suits the kitchen better
If the kitchen already sits under a flat or lean-to roof with room for a larger opening, a rooflight or lantern will usually light it more and give a view of the sky.
A sun tunnel is the right answer when the kitchen is under a deep loft or another floor, when the roof above has no room for a glazed opening, or when you only need one dark corner lit. Where the kitchen is in a single-storey extension, such as a Romsey side return with a flat roof, a flat rooflight or a roof lantern over the island tends to do more, because the opening is larger and there is no tube to lose light along. Many kitchen extensions combine the two: a rooflight over the dining end and a small tube over a dark utility or larder. The sun tunnel installation page sets out where a tube fits in the wider plan, and our light planning guide explains how we decide between them for a given room.
How much light any single tube gives depends on its diameter, its length, the number of bends, the dome and the sky that day, so we do not quote a single figure for a kitchen. The survey measures the real route and the written light plan states the diameter and position we recommend. You can book a light survey or message us on WhatsApp.
Questions people also ask
Can a sun tunnel go directly above a hob?
It is better not to. Rising heat, steam and grease reach the diffuser first, dulling it and adding moisture to the tube. A position over the worktop beside the hob gives light where you prepare food without taking the full plume from the pans.
Can a sun tunnel replace a kitchen window?
No. It brings in daylight but gives no view and no opening for fresh air, and a kitchen still needs ventilation to meet the Building Regulations. It works as an addition that lights the part of the room the window cannot reach.
Can I use it for light in the evening?
After dark a plain tube gives nothing, but some kits take an LED module inside the diffuser so the same fitting works as a ceiling light. Our guide to sun tunnels with LED lights explains how those kits are wired.
Does fitting one in a kitchen need Building Control?
It depends on the work, such as whether a joist is cut or a fire-separating ceiling is crossed, rather than on the room. Building Control decides, and we handle the notification when the work is notifiable. See do sun tunnels need building regulations.
