Walk through a typical terraced house and count the rooms without a window. The inner bathroom, the upstairs landing, the hallway behind the front door: these are the places where the light switch is the first thing you reach for, every day, whatever the weather. They are also the rooms where a sun tunnel makes the biggest difference.
The two types of room ask different things of the product, though. A bathroom is about moisture and privacy. A hallway or landing is about spreading light along a space people pass through. Moisture and privacy come first in the bathroom; spreading light along the length of the space comes first in the hall.
Why these rooms suit a tunnel
A room with no outside wall cannot have a conventional window, and where there is a loft above it, a roof window has nowhere to sit either. A sun tunnel solves both problems at once. The dome sits on the roof, the tube crosses the loft and the diffuser lights the room below.
It also leaves the outside walls and the look of the front of the house untouched, which matters in terraces and semis where the street elevation is part of the home's character.
Bathrooms: the moisture question
Steam is the thing to plan around. Warm, damp air rises, so the seal between the diffuser and the ceiling must be tight, and the tube is wrapped in insulation where it crosses the cold loft. That keeps moist air from reaching a cold surface inside the run and condensing.
A bathroom extractor fan that vents to the outside helps more than anything else, with or without a tunnel. If your bathroom has none, we mention it at the survey so you can decide whether to fit one at the same time. Our answer on whether sun tunnels cause condensation goes into the detail.
Bathrooms: privacy and the feel of the room
The frosted diffuser blocks the view both ways. That makes a tunnel a comfortable choice over a bath or shower, where a clear window would need a blind. The light is soft and even, and it changes with the weather, which is hard to get from a bulb.
Position matters. Many people like the diffuser over the basin or at the end of the bath, so the brightest point falls where they need it. We mark the ceiling at the survey so you can judge before we cut anything.
Bathroom checklist
- Is there an extractor fan, and does it vent outside?
- What finish is on the ceiling around the diffuser?
- Where is the light needed most: bath, basin or shower?
- Is there a cold water tank or pipework in the loft above?
Landings and stairwells
A landing is the clearest case of all. A narrow staircase with one small window at the bottom leaves the top in permanent dusk, and the bedroom doors open onto a dark corridor. A tunnel above the landing lights the whole run, and it carries down the stairwell so the steps themselves are easier to see.
Because a landing is usually small and has a short, clear ceiling, the tube route is often direct. The only extra thing to look for is what sits in the loft over the stairs, since this is where water tanks and old chimney stacks tend to be.
Inner hallways
In many houses the hallway borrows its daylight from the glass in the front door and little else. On a grey afternoon it can feel like a cellar. A tunnel makes the hallway a place with a sense of the day, and it can brighten rooms whose doors stay open onto it.
Where the hall sits beneath a bedroom, there is no roof directly above it, so a tunnel would have to cross the bedroom's ceiling space, which does not work. In that case the survey looks at another route or at a different product. Sun tunnel or roof window sets out the alternatives.
What you will notice day to day
A tunnel is silent and has nothing to switch on. In the morning the diffuser brightens as the sky does, and on a bright day it can light a small bathroom without the bulb. On an overcast day the glow is softer, and in the evening the room still needs its ordinary lights.
Some diffusers have a light fitting built in. It lets you use the same ceiling circle for both day and night, and it can be fitted at the same time if you want one.
Houses with a dark middle
Many older homes, and a good number of newer ones, share the same quirk: a middle that is far from any window. In a Victorian terrace it is the stair and the landing. In a 1930s semi it is the inner hall and the bathroom over the porch. In a bungalow it is the corridor between bedrooms.
These spaces are rarely discussed when people list what they want from a house, yet they make up much of the daily route through it. Lifting the light in them changes how the whole home feels, and does it without touching a single outside wall.
Looking after it afterwards
Once fitted, there is little to do. The dome on the roof collects dust and leaves, and a rinse from time to time keeps the light strong. Indoors, the diffuser can be wiped with a damp cloth. In a bathroom, keep the extractor fan in use and clear the vent so moisture is carried out.
If you ever notice a faint tide mark on the ceiling around the ring, or a drip of water, tell us as soon as you can, since it is the first sign that something in the run needs a look. Everything we fit is covered by the 10-year workmanship guarantee.
Doors, extraction and air
A hallway that gains light from a tunnel often has doors that open off it. Leaving them open spreads the light into the next room, and fitting glass panels or a fanlight over a door carries it further still. If the hallway doubles as a place where coats and shoes pile up, a brighter space also makes it easier to find what you need before leaving the house, and glazed internal doors carry it further. In a bathroom, a closed door keeps steam in the room, so a fan is useful whichever way you do things.
A tunnel does not ventilate. If fresh air is also a goal, a roof window is the product that opens, and in a loft bathroom it may be the better choice. Where that is not possible, an extractor is the practical answer.
Cloakrooms, en-suites and other small rooms
The same thinking applies to any small room with no window. A downstairs cloakroom tucked under the stairs has no roof above it, so a tunnel is not an option there. An en-suite on a first floor, with a loft over it, is a good candidate. A walk-in wardrobe or a landing cupboard lit by a small tube is easier still, since a narrow diffuser is enough for a room used for a minute at a time.
Size the circle to the room, and to the people who use it, since a child's bathroom, a guest en-suite and a family shower room all want slightly different amounts of light. A large diffuser in a very small space can look out of proportion, and a narrow tube that passes between tight rafters may be the only one that fits. We show you the circle drawn on the ceiling so you can judge it in place.
Lath and plaster, plasterboard and tiled ceilings
What the ceiling is made of changes how the diffuser goes in. Plasterboard is quick to cut and make good. Lath and plaster, common in houses built before the middle of the last century, needs a careful cut so the surrounding plaster stays sound. Our fitters protect the area and choose where to start the cut to limit damage.
In a bathroom, the ceiling may be tiled or boarded with a moisture-resistant finish. The ring is fixed to the structure behind it and sealed with a bead that suits that surface. The aim in every case is a tidy, flat finish with nothing for steam to find a way through.
Matching the light to the way you use the room
A family bathroom used at seven in the morning and again at eight in the evening gets its best light between those two times. A hallway that is walked through at all hours gains most when the sun is high. A landing in a house where people work from home can feel pleasantly different once daytime light reaches it.
A quick test is to stand in the room at different hours for a day or two and notice when you reach for the switch. Those are the hours a tunnel will cover. Think about when you are actually in the room, and tell us. If it is used mainly after dark, a tunnel gives less benefit and a roof window or electric light may do more. If it is a room you pass through by day, a tunnel is hard to beat.
What the fitting involves
We cover the landing or bathroom floor and the stairs, then go on to the roof and lift the covering at the chosen spot. The kerb and flashing go in, the tube is run through the loft and wrapped, and the ceiling is cut. The diffuser goes in last and the ceiling is made good.
Because the opening is small, the roof is made weathertight quickly, and it is closed up at the end of each day. When we hand the house back, we go through the new tunnel with you and leave the maker's paperwork, the warranties and our 10-year guarantee in your hands.
Windowless rooms and the rules
There is no Building Regulations requirement for daylight in a room in an existing house, so a tunnel is a choice you make for comfort, not compliance. What the rules do cover is the new opening itself. It needs Building Regulations approval for the structure and thermal performance, and we arrange the notification where the work is notifiable.
Planning is simpler for most houses. Rooflights are usually permitted development, though flats and maisonettes need permission, and listed buildings need consent. An Article 4 direction on a street can also remove the right, and the council confirms. Our planning permission guide sets out the conditions.
Deciding and booking
If you are weighing up a bathroom or hallway, the cost guide sun tunnel cost, fitted shows how the price is built. The wider picture sits under sun tunnel installation. The quote form arranges a free survey, and a written quote follows that itemises every cost.