Choosing VELUX blinds for your roof window, matched by size code

The VELUX blind range splits into two halves: blinds that hang inside the room and blinds that shade the glass from outside. Inside, you choose a fabric and a fold. Outside, you choose a product that stops the sun before it reaches the pane.

Inside the room the families are the blackout blind, the pleated blind, the roller blind, the Venetian blind and the honeycomb blind. Each comes in a spread of colours and fabrics. On the outside there is the awning blind, the roller shutter and the roller blind made for outdoor use. Insect screens and a few other accessories round out the list. Not every type is offered for every window size, and the catalogue is updated, so treat any list, including this one, as a map of the territory and check the current range for your exact window.

Within each family the operation can differ. A blind can be worked by hand, by a pole, by a motor on the same system as an electric window, or by a small solar panel that charges the motor. That last point matters more than it sounds, because a blind that cannot easily be reached is a blind that stays open. The power options are covered further down.

A quick word on the word "genuine". Blinds sold for VELUX windows by other makers exist, and some are well made. We write about the VELUX range here because it is the one designed around the VELUX frame, with fixings that fit the sash as supplied. If you are weighing an alternative, the same questions below still apply.

A roof window slopes, so a blind has to fight gravity and stay tight at the edges. The VELUX blinds do this with side rails that fix to the sash, so the fabric slides along a fixed path instead of hanging free.

On a wall window a blind drops from the top and gravity does the holding. On a window set at 35 or 45 degrees, the fabric wants to fall toward the glass and bow at the sides. A rail that clips to the sash holds the edges in place, keeps the fabric parallel to the pane and leaves a narrow, even gap. That gap is what lets a blackout blind keep a room truly dark, since light that creeps round the frame is what you see at five in the morning.

The rails also mean the blind moves with the sash. If you open the window for ventilation, the blind stays attached. The clearance between blind and glass is designed rather than improvised, so a handle or ventilation bar does not catch on the fabric. We cover that part of the window in the VELUX ventilation bar and handle explained.

One consequence is that the blind and the window are a matched set. A rail made for one sash is not a fit for a different sash, which brings us to the size code.

Every VELUX roof window carries a two-letter, two-digit size code, such as CK02 or MK04. The same code appears on the blind box, and it is the single fact that decides which blind will fit.

The letters describe the outer width and the digits the height of the frame, so a code tells you the footprint of the window in the roof. A blind ordered against that code is cut to that sash, with rails and brackets to match. If the code on the blind does not match the code on the window, it does not fit. There is no trimming to size and no stretching to fit.

So the first job is to find the code. It is printed on the data plate, which lives in a place worth knowing, and we show you where in where the data plate is on a VELUX window. If the plate has gone or is unreadable, there is a way to work the code out from measurements. For a fuller account of how the letters and numbers are built, read how to read a VELUX size code.

Two other details matter for ordering. The type of window matters as well as the size, because a blind made for a top-hung window and one made for a centre-pivot window may use different fixings. And if you are replacing the window, the old blind will not automatically carry over to the new one, because the sash may have changed. Plan the blind with the window rather than afterwards.

A blackout blind is the one to choose when the room has to go dark. The fabric is a dense, coated weave, and because it runs in side rails, there is very little gap at the edges for daylight to use.

In a loft bedroom, this is usually the first blind to fit. Summer light arrives in the small hours, and a pitched window faces more sky than a wall window does. A good blackout blind turns a bright attic room into a proper bedroom within a second or two. It is also the type most often chosen for a nursery, for the simple reason that a dark room at nap time is the aim.

There are limits worth stating. A blackout blind works on light. It does not meaningfully change what the room hears, so for a flight path or a rain-on-glass problem the answer sits in the glazing build, not the fabric. We take that up in whether VELUX blinds reduce noise. And because the blind sits close to the glass, the pane behind it can run warm on a sunny afternoon, so a dark blind is for darkness and not a cure for overheating.

For the full case of which type suits a sleeping room, including cord and reach questions, see which VELUX blind is best for a bedroom.

Pleated and roller blinds are the two plainer choices, and both handle the ordinary day well. They soften light rather than removing it, and they are the usual pick for rooms that are lived in rather than slept in.

A pleated blind folds the fabric into narrow creases that stack at the top or the bottom of the sash. Because the weave is lighter, it spreads sunshine into an even glow and takes the glare off a screen. Drawn up from the bottom, it can cover the lower glass while the upper pane stays clear. That makes it a sensible choice for a study, a landing or a spare room.

A roller blind is one sheet wound on a tube. It has the thinnest stack of the inside types, which suits a small window or a shallow lining, and it comes in both light-filtering and darker fabrics. The trade is simplicity for control: a roller is essentially all or nothing, unless you stop it part way.

When you hold a pleated and a roller side by side, the difference is mostly how the room should feel. A roller is clean and flat. A pleated blind is softer and lets you set two zones of light on one window. If the blind will be partly drawn all day, the pleated type usually looks better in that half-open state.

A Venetian blind uses slats you can tilt. A honeycomb blind uses folded cells that hold still air against the glass. They solve different problems: one is about steering sunlight, the other about keeping warmth in.

The Venetian blind is the tool for a room where the sun moves across the day, such as a home office. Tilting the slats bounces the light up toward the ceiling and keeps the glare off the desk. Aluminium slats also cope well with damp air, which is why the type is often suggested for kitchens and bathrooms. The price of that control is that the slats gather dust and are rarely fully dark.

The honeycomb blind does its work in winter as much as summer. Each cell traps a thin layer of air, and on a cold night that layer slows the loss of heat through the glass. In a loft room the roof window is often the coldest surface, so the effect can be felt on the skin. It is a small comfort on top of a well-glazed window, not a substitute for one. The cells also take the edge off echo in a bare attic room, which is about how the room sounds inside, not what comes in from outside.

A honeycomb blind drawn tight at night can leave the pane colder behind the fabric. In a humid room, that can mean moisture on the glass. Lifting the blind in the morning is the habit that solves it.

The table sets the five inside families against the questions people actually ask. It is a guide to trade-offs, not a ranking, and fabrics within a family vary.

Read the stack column against the depth of your lining. A deep, well-finished reveal leaves room for any of them. A shallow one favours the roller. How the lining is finished is decided when the window goes in, which is one more reason to settle the blind early.

An outside blind is the only kind that stops the sun before it reaches the glass. That is a different job from any blind inside the room, because once the sun has passed through the pane, the heat is already in the building.

An awning blind hangs over the outside of the window. The pane stays cooler, the air behind it stays cooler, and a loft room under a south or west pitch is easier to live in on a hot afternoon. A roller shutter takes the same idea further, closing the window off completely, which also adds darkness and a further layer of protection from the weather. The awning is the gentler option, because you keep some daylight and a little of the outlook through the mesh.

The outside products need planning. They have to be fixed to the frame, and if they are powered they need a cable route or a small solar panel. They also live in the weather, so the mounting and the fabric are made for exposure. They are easiest to add while the window is being installed, because the flashing, the frame and any wiring are all open. We explain the awning in more detail in what a VELUX awning blind is for.

Outside and inside work well together. A common pairing on a hot bedroom roof is an awning outside to take the heat and a blackout blind inside for sleep. Choosing both at once means the brackets, rails and any power supply are planned in a single visit.

There are three ways to move a VELUX blind: by hand or pole, by a mains motor, or by a solar-charged motor. Which is right depends almost entirely on where the window sits in the ceiling.

A manual blind works well when the bottom edge of the window sits around chest or waist height. You reach it, you draw it, nothing more is needed. If the window is set higher in a steep slope, a pole can help, but for a window you cannot comfortably reach a motor is the better choice.

A mains-powered blind shares the same system as an electric window. The motor and the wiring are planned together, and one remote or wall control can operate both. That is the tidy answer in a new build or a loft conversion where a wiring route can be hidden in the lining. The window side of that system is explained in VELUX INTEGRA electric roof windows.

A solar blind carries its own small panel and needs no cable. That suits an existing window where chasing in a new wire would mean opening up the finished room. The panel needs daylight to charge, which a roof window usually has in plenty. If your window is also solar powered, the matching choice is described in VELUX solar powered roof windows.

Cords deserve a thought in any room where a child might reach them. A pole-operated or motorised blind avoids loose cords, and any cleats should sit well out of reach.

Start with how the room is used, then let the window's height and orientation narrow the list. The catalogue is wide, but the decision is usually one or two types per room.

The loft bedroom

A blackout blind on the inside, operated from the bed or the floor, is the starting point. Add an awning outside if the pitch faces south or west. The glazing build is a separate decision: dark does not mean quiet, and the quiet spec we write names the glass first. Sizing the window itself is a separate step.

The study or home office

A pleated blind in a light-filtering fabric gives a steady, even light with no glare on the screen. Where the sun crosses the desk, a Venetian blind lets you steer it. A second, darker layer is useful if the room doubles as a guest bed.

The bathroom and kitchen

Damp air rules out fabrics that hold moisture. Choose aluminium slats or a roller in a wipeable, moisture-resistant fabric, and give the room a way to clear steam. The window needs the same thought, covered in fitting a VELUX window in a bathroom.

Every quote we write comes with a quiet spec, and blinds appear in it in their proper place: a light and comfort choice, never the answer to noise.

The spec records what we heard at the survey, the glazing build we propose and why, and how the seals and upstand are finished. For a bedroom the blind is listed beside the glass, so the two choices are made together. You can read what the document covers on the quiet spec page. If you want blinds considered alongside a new or replacement window, say so when you get a quote and tell us which room each window serves. We can then size the window, the blind and the glazing in one pass.

The wider service, from choosing the model to the finish inside the room, is set out on VELUX window installation in Crawley.

These come up most often when someone is comparing types, and each has a short answer.

Can I use the blind from my old window on a new one?

Only if the size code and window type match. A blind is made for one sash, so a new window of a different size needs a new blind. Plan them together.

Will a blind stop the room getting hot?

An inside blind reduces glare and slows the spread of heat, but the heat has already come through the glass. For a hot top-floor room, an outside awning deals with the sun earlier.

Do I need a blind if the glass has a solar coating?

Usually yes. A coating reduces the heat that passes through but does not darken the room, so a blackout blind is still what you want for sleep.

Which blind is easiest to live with?

A pleated blind in a light-filtering fabric is the simplest everyday choice, since it softens light without going dark. Choose a blackout for bedrooms, and a motor where the window is out of reach.