Choosing curtains and blinds

What are you covering it for?

Before choosing a window covering, decide what you most want to solve at that window. For a bedroom where morning sun wakes you, blocking light comes first; for a low-floor window facing the street, daytime privacy; if the window area is noticeably cold in winter, insulation. A living room that should be bright by day and covered at night suits a type that makes light easy to adjust. If you have more than one aim, combine them: sheer and heavy curtains together, or a blind with curtains over it.

• Blocking light: bedrooms, sleeping during the day
• Privacy: windows near the street or facing buildings
• Insulation: homes where the window area is cold in winter
• Light control: living rooms used differently by day and night

With curtains, start with the pole

Where you put the pole or track changes the look of curtains a lot. Mount it a little higher than the top of the frame and wider on both sides, and when the curtains are open the fabric does not cover the glass, letting in more light and making the window look larger than it is. In a room with a low ceiling, a track near the ceiling with curtains falling close to the floor lengthens the vertical lines and makes the ceiling seem higher. If you cannot drill, look for tension rods that fit inside the recess or other no-drill hanging options.

How to measure for curtains

Measure from the pole or track, not the window. If the width matches the track exactly, the fabric is stretched flat when closed, with no folds, and looks plain, so choose a width more generous than the track. How generous depends on the fabric weight and how full you want the folds, so follow the retailer's guidance. For floor length, keep the hem just clear of the floor so it does not drag; if there is a heater or furniture under the window, a length that stops just below the sill is safer.

• Width: more generous than the track
• Floor length: measure from track to floor, then leave a small gap
• Sill length: a little below the sill
• Keep fabric off any heater

Fabric and blocking light

Even in the same colour, fabrics let in very different amounts of light. Sheer fabrics soften the view in by day while letting light through; dense, heavy fabrics or those with a blackout lining block much more. If you need real darkness, the light leaking around the sides and top matters as much as the fabric. Mount the pole wider and higher than the window and let the curtains wrap back towards the wall to reduce leaks. Check before buying whether the curtains can be washed and whether they shrink. Curtains collect dust, and if they are hard to clean they soon look dingy.

Types of blind

Blinds take up less bulk than curtains, so they suit small rooms and windows in front of a desk. Each type handles light differently, so choose by use.

• Roller blind: fabric rolls up. Simple and neat, but light is controlled only by raising and lowering
• Venetian blind: slat angle gives fine control over light and view. Dusting between slats is a chore
• Day-and-night blind: sheer and solid stripes slide over each other to adjust light
• Roman blind: folds up and gives a soft, curtain-like look
• Vertical blind: for wide openings such as large windows or patio doors

Measuring and mounting blinds

First decide whether the blind goes inside the window recess or on the wall outside it. Inside looks neat but needs enough depth, and you must check it will not hit window handles or insect screens. Recesses are often less square than they look, so measure the width at the top, middle and bottom and use the narrowest. Mounted outside, a blind can overlap the frame, cutting light leaks at the sides and making the window look bigger. If you order made to measure, state clearly on the order whether your measurements are for inside or outside the recess.

Insulation, condensation and safety

Windows are where a lot of heat moves in and out of a home. Closing heavy, floor-length curtains at night helps reduce the chill near the window, and drawing them on summer afternoons keeps sun out so the room heats up less. But trapped air between glass and curtain can cause condensation, and mould easily forms on the hem, so open the curtains and ventilate in the morning. In homes with young children, hanging cords on blinds and curtains are a strangulation hazard. Choose cordless designs, or secure cords high out of reach, and keep beds and chairs away from windows.