Which blinds suit roof windows?

An ordinary roller blind hangs straight down from a fixed point. A roof window slopes, and the sash opens by swinging or pivoting, sometimes through a wide arc. A blind has to hold itself against the slope, stay tight to the glass and move with the sash, so most are made with side rails or guide cords rather than free hanging.

The window's position changes the choice. A north slope sees less direct sun than a south or west one, so a north-facing bedroom may need only a blackout blind, while a west-facing study may need heat protection as well. Think about which room, which slope and which time of day causes the trouble.

The glass itself is also under more pressure. It faces the sun directly for much of the day, so the blind sits closer to heat and light than a wall-window blind ever does. Cheap fabrics fade, and fittings can warp. It pays to use a product designed for the window, in the right size code, fitted to the frame as intended. Our page on roof window sizes explains how the codes work.

Light at a roof window arrives early in summer and from above, so a bedroom with one benefits more than most from a proper blackout blind. A good one has side channels that trap the light which would otherwise leak around the edges, and a fabric with a blackout coating.

Ask about the fabric colour on the window side. A pale or reflective face turns back more of the sun than a dark one, and a dark inner face hides finger marks. Many blackout blinds offer a different finish on each side for this reason.

Sleeping is not the only reason. Blackout blinds also help with insulation to a small degree, because the trapped air layer between blind and glass slows heat loss on winter nights. They do not replace good glazing, but they help.

The trade-off is the room in the daytime. Fully closed, the room is dark, so many people pair a blackout blind with a lighter second blind, or choose a blind that can sit part-way down.

Loft rooms with large roof windows can become uncomfortably warm, as covered on our page about why a skylight makes a room too hot. A blind helps most when it stops sunlight before it passes through the glass. External roller blinds and awnings do exactly that, and usually give the best protection from summer heat. They are exposed to wind and weather, so they are built more robustly and cost more.

Internal blinds with a reflective coating or a honeycomb structure also reduce heat gain, though some warmth still enters the room. A light colour on the glass side reflects more than a dark one.

Whatever you choose, check that it does not block the window's ventilation setting. A blind that traps hot air against the glass can make the glass hotter.

The same reasoning as for electric windows applies. A window high on the slope, or above a staircase, is awkward to reach, and a blind you cannot lower is a blind you do not use. Motorised blinds run from a wall switch or remote, and solar versions recharge from daylight and avoid cabling.

If you are fitting a new window anyway, electric blinds are cheaper to plan in from the start, because any wiring goes in when the lining is open. Our page on electric roof windows compares the costs.

Battery life is worth asking about. Solar blinds usually hold a charge through dull weeks, but a long run of dark days in December can test them, and a spare charging option is handy. Mains versions have no such limit but need an electrician.

For a manual blind on a high window, a telescopic pole is the simple fix, though it is another thing to keep to hand.

A closed blind can trap warm, moist air between itself and cold glass and make condensation worse on winter mornings. Opening the blind or the window slightly after a night in the room, and running a bathroom extractor, usually helps. A blind does not fix condensation, and it can hide the early signs of seal failure.

Blinds can also change the rain noise a little, since a layer of fabric softens the sound that glass transmits; see roof window rain noise for the glazing options that matter more.

Measure carefully before ordering. Blinds are usually matched to a size code printed on a label on the window frame, often on the sash edge, and the wrong code means a blind that gapes or binds. If the label has worn away, measure the glass and frame and check with the supplier before paying.

Blinds clip or screw to the window frame, so no roof work is needed, and many people fit them themselves. Work from the inside, take care with the frame, and follow the instructions for your model.

Check the cords, rails and fabric once a year, along with the window itself; our roof window maintenance page covers the routine. Never rest weight on the frame, and avoid pulling a blind sideways.

If your window has a leak or a worn seal, a blind will not cure it, and the flashing is the likelier culprit; see roof window flashings. We survey the roof, send photographs of your own roof and put the repair in a written quote. Our skylights and roof windows page has more.