Do Roller Blinds Keep the Heat Out? What Actually Works in an Australian Summer

Yes — a roller blind makes a real difference to a hot room, and the wrong one makes almost none. The fabric, the colour and how tightly it fits the window decide which you get. Here's how to pick for a west-facing room in January.

Sunscreen rollers in a living room. The weave cuts glare and a good share of the heat while you keep the view — this is the summer fabric for rooms you live in during the day.

How heat gets in, in one paragraph

Sunlight comes through the glass as radiation, hits whatever is behind the window and turns into heat. A blind stops the sun landing on your floor and furniture, and reflects or absorbs it at the window instead. It can't stop the glass itself getting hot — that's what external awnings and good glazing are for — but it stops the room becoming a solar oven, which is most of the problem. The more of the window the blind covers and the more it reflects, the better it works.

Blockout, sunscreen or light-filter for heat?

For pure heat, blockout wins (see it in real homes). For a room you actually sit in at 4 pm, sunscreen is the honest answer: it takes the sting out of the sun and the glare off the TV without turning the room into a cave. A lot of people put a double roller on the worst window — sunscreen at the front for the afternoon, blockout behind for the night — and stop thinking about it.

Colour matters more than people expect

Two blinds in the same fabric, different colours, will perform differently. A light-coloured face reflects sunlight back out of the window; a dark face absorbs it and re-radiates some into the room. So for heat, pale on the window side is better.

The catch is glare and view. With sunscreen fabric, a dark weave is easier to see through and cuts glare harder, which is why the charcoal blinds in the photo above look so good from inside. If your priority is the view and the glare off a screen, go dark. If it's pure temperature in a room you don't look out of much, go light. (More on choosing a blind colour.) Most of our blockout fabrics have a pale backing on the window side whatever colour faces the room — turn the swatch over to check — so with blockout you can usually pick the colour you like.

The fit decides how much of the blind's work you keep

Three white rollers down in a media room. Fitted on the face of the wall so they overlap the openings — no bright edges, no heat sneaking round the sides.

A roller fitted inside the window recess leaves a slim gap each side and the roll sits a little below the top of the frame. On a shaded window that's fine. On a west window in summer those gaps are bright, hot stripes, and the light bouncing around the recess warms the reveal. The roller blinds buying guide walks through recess versus face fit.

A simple plan for a hot room

What about curtains?

A curtain hanging clear of the glass traps a layer of air, which helps both in summer and winter, and a lined blockout curtain in a west bedroom is excellent. Sheers alone are lovely but do little for heat. The combination that turns up in most of the homes we photograph — sheer curtain in front, blockout or sunscreen roller behind — gives you the soft look and a blind doing the thermal work.

Common questions