Best window treatments to keep your home warm

Best window treatments to keep your home warm

Tags: Tips, Heat retention,

Did you know that up to 45% of your home’s heat is lost through the windows? Window treatments can make a huge difference to how warm your home is. But which products perform best when it comes to heat retention?

Read on to find out!

The challenge

According to a recent study by Consumer NZ, if you have an insulated house you could be losing upwards of 45% of your home’s heat through the windows. In an uninsulated home this figure is closer to 30% (as it’s easier for heat to escape through the walls, ceiling and floors).

With more than 30% of the average Kiwi household’s power bill spent on heating and cooling, that’s a significant energy cost too.

The results

Consumer NZ’s report showed that when it comes to heat retention, any window covering is better than a bare window. Testing proved window treatments could have a significant impact in how warm and comfortable your home will be over winter.

Honeycomb blinds were a clear winner for their insulation benefits, keeping 63% of heat in.

Next were Roman blinds, followed by lined curtains and then roller and Venetian blinds, which achieved similar results in the test.

Window treatment heat retention test results

Note: The Consumer NZ test did not include shutters, which also have good insulation properties (read more about shutters below).

Honeycomb (Thermacell) blinds

Honeycomb blinds are by far the most effective window treatment for heat retention. The unique construction of honeycomb blinds traps pockets of air to create an insulating barrier against cold windows. They’re also fitted closely inside the window jamb, with only a minimal gap on the sides.

Honeycomb blinds close up


Installed in a tight-fitting frame, shutters can reduce heat loss through windows by up to 30% when the slats are closed. They’re also a great solution for shaped windows, such as circular or triangular windows, which are often left uncovered due to their tricky shape. These windows are often the ones that are high up, so they really do let the heat out as it rises up.

Grey shutters above a bed

Roman blinds

Roman blinds make an excellent insulator. For best performance, they should be fixed outside the window frame to form a close-fitting cover over the entire window. This comes with the added benefit of blocking out more light, making these a great choice for bedrooms.

Roman blind in a guest bedroom


With their extra layer of fabric, lined curtains are your best choice when it comes to insulation. Blockout thermal linings are available in a wide range of colours to perfectly match your choice of curtain fabric.

Curtains perform best when they are floor-length and fitted as close as possible to the window frame. They should be a good width, overlapping the window frames at the sides.

Lined dining room curtains

For more product advice and to find the best solution for your home, book your free consultation today.