Electric blinds fitted inside the rooflight

Integral blinds, between the panes

A blind sealed inside the double glazed unit, operated magnetically or by a small motor within the cavity.

For: never needs cleaning, cannot be damaged, no dust, and it leaves the room side of the glass completely clear. On a rooflight above reach that is a real advantage.

Against: if the blind mechanism fails, the whole sealed unit is replaced, because it cannot be opened. It also adds cost to the unit and slightly affects the thermal specification.

Internal blinds, below the glass

Fabric blinds in tracks on the room side, as on a standard roof window.

For: a wide fabric choice including blackout, and repairable or replaceable independently of the glazing.

Against: collects dust on an upward facing surface that is above reach, and the mechanism is exposed.

Neither controls heat

The important point. An internal blind sits behind the glass, so the solar energy has already entered the room. It absorbs it and re-radiates it as heat.

An integral blind is inside the sealed unit, which is better, and still not as effective as solar control glass, which stops the energy at the outer pane.

Specify solar control glass for temperature. Use blinds for glare, privacy and blackout.

Power

Electric blinds need a supply, separate from the rooflight’s own. Run it at first fix along with everything else. Solar powered blind options exist and follow the same logic as solar openers.

Decide early

Integral blinds must be specified when the unit is made. They cannot be added later at all.

What an integrated blind is

Not a blind hung near a rooflight, but one designed for the specific model, running in channels built into the sash or the frame, so the fabric sits flat against the glass with no gaps at the sides.

That side channel detail is what distinguishes a proper roof blind from a domestic one and it is why a blackout blind for a rooflight genuinely blacks out rather than dimming. Light cannot leak past the edges.

Because the blind is matched to the model and size code, it fits exactly, goes on without tools, and costs considerably less than a made to measure blind fitted to a plaster reveal.

When to make it electric

The threshold is the same as for motorising the window: roughly two and a half metres to the operating point.

Below that, a manual blind operated by hand is perfectly good and considerably cheaper. In a loft bedroom where you can reach the blind standing up, manual is the sensible answer and a motor is hard to justify.

Above that, a pole becomes a chore, and a blind that is a chore to adjust stops being adjusted. It ends up permanently up or permanently down, at which point you have paid for a blind and are using it as a fixed panel.

The other case for electric is scheduling: a blackout blind that closes automatically at dusk in a loft bedroom, or an external awning that deploys on a temperature trigger and retracts in high wind.

The three ways to power one

Mains. A cable to the window. At first fix during a build that is twenty minutes. Into a finished room it is the same disruptive exercise as motorising the window: lifting flooring or ceiling, chasing a wall, making good and redecorating.

Frequently several times the cost of the blind itself, which is why it is rarely the retrofit answer.

Battery. A rechargeable pack, either integral or mounted nearby. No wiring, and the battery needs recharging periodically, which on a high level window means getting to it. That is manageable annually and tiresome if it is more often.

Solar. A small photovoltaic panel on the blind or the window powers it, with no connection to anything. This is the sensible retrofit choice, and where the window itself is already solar powered the blind runs on the same principle with no additional wiring question.

If the window is already motorised

Much easier than starting from scratch, and worth checking before assuming new cable is needed.

There is already power at the window and frequently a spare output on the control unit, so adding a blind may be a matter of connecting and configuring rather than running anything new.

That is one of the quieter arguments for specifying a motorised window in the first place, or at least for running a capped cable to the position.

Ordering with the window

Do it. Three reasons.

The sizing is certain, because the blind is matched to the model and size code rather than measured on site. The fitting happens on the same visit at no additional access cost, which on a high level unit is not trivial. And where power is needed, the cable is run while the ceiling or the reveal is open.

Retrofitting a blind is entirely possible and it means another visit, another access arrangement and, for a powered blind, another decision about cabling.

What the different types are for

Blackout. Opaque fabric in side channels. The one that matters over a bedroom, particularly an east or west facing rooflight that admits daylight from very early or keeps a room bright until late.

Pleated or translucent. Diffuses light and gives privacy without darkness. Suits a bathroom, a landing or a study where glare rather than light is the issue.

Venetian. Adjustable slats, allowing light to be directed rather than blocked.

External awning. A different product in kind, fitted over the outside of the glazing. Far more effective against heat because it intercepts the sun before it reaches the glass.

The heat point, stated plainly

An internal blind is a light and privacy product. It is not a solution to overheating.

By the time an internal blind stops the sun, the energy has already passed through the glass and is inside the room. The blind absorbs it and re radiates much of it back into the space. It is roughly a third as effective as an external awning at controlling heat.

Where a room overheats, the answers in order are solar control glass specified at order, an opening vent at the highest point so accumulated heat can leave, and an external awning. An internal blackout blind sits alongside those for its own purposes rather than instead of them.

On a south or west facing bedroom rooflight the right specification is usually both: solar control glass for the heat and a blackout blind for the light.

Conservation rooflights

Steel conservation units generally do not carry the clip in accessory ranges that mass market roof windows do. Blinds become a separate made to measure item fitted to the reveal, which costs more, never sits as neatly, and does not have the side channels that make a blackout blind black out.

Budget for it at the start rather than discovering it at the end, and where blackout matters in a room with a conservation rooflight, discuss it before the unit is chosen.

Control and integration

Most motorised blinds take a wall switch, a handheld remote, or app control, and can be grouped with the window so one command operates both.

The same caution applies as to the window itself. Treat app control as an addition rather than the means of operation, and specify a physical switch alongside it. A blind that only responds to a phone is a blind that does not work when the network is down, and a blackout blind in a bedroom is exactly the sort of thing you want to work at midnight without troubleshooting.

Maintenance

Very little. Keep the side channels clear of dust, because that is what makes a blackout blind run smoothly and seal at the edges. Vacuum the fabric occasionally.

On a powered blind, the motor is a small mechanism with a long life, and the battery on a solar or battery unit is the consumable.

Where a blind sits against the glass in a room that produces moisture, a bathroom or a kitchen, expect it to need cleaning more often, and choose a fabric rated for humidity rather than a domestic curtain material.

The integrated position

Some rooflights are made with the blind housed within the unit itself, between the panes or within the frame section, rather than fitted to the room face afterwards.

That arrangement has real advantages. The blind is sealed away from dust, it never needs cleaning, it cannot be damaged, and the internal face of the rooflight stays clean and uninterrupted.

It also means the blind cannot be replaced without replacing the unit, which is the trade.

The more common arrangement

A powered blind mounted on the room face of the frame, running in side channels, operated by remote.

The side channels are the important part. On a raked or horizontal surface a blind cannot hang, so it has to be held against the glass along its whole travel. That is what makes blackout actually black out, because light cannot leak past the edges.

Frame mounting matters too: on a centre pivot roof window the blind travels with the sash, so the window still opens normally. A blind fixed to the plaster reveal does not, and it obstructs the window every time.

Mains against solar

Mains is the right choice on new work where the roof is open and the cable costs almost nothing, particularly where the rooflight is already wired for a powered opener. The blind can then be grouped with the window on one control.

Solar is the retrofit answer. A small panel, a battery and a remote, addable at any time with no cabling. The trade is a battery with a service life of a few years and slower operation.

On a finished room, solar is almost always the sensible route, because running a cable means surface trunking or opening up a ceiling.

Grouping and scheduling

Where several blinds are fitted, plan the groups before the cables go in. Rearranging afterwards means going back into the ceiling on a hardwired system.

A blind that can be scheduled is genuinely useful on a south facing rooflight: closing automatically through the hottest part of the afternoon while the house is empty prevents the overheating rather than dealing with it afterwards.

What it does thermally

A blackout blind held in side channels traps still air against the glass, which reduces heat loss on a cold night and heat gain on a hot afternoon.

For summer overheating specifically, an external awning does considerably more, because it stops the energy before it reaches the glass. The blind handles darkness and glare; the awning handles heat.

Access for replacement

A blind housed within the sealed unit cannot be replaced without replacing the whole unit, which is worth knowing at purchase.

A frame mounted blind unclips and is replaceable, and that is the more practical arrangement on anything you expect to keep for twenty five years.