Do I need new windows? 

Windows are an important source of insulation for most homes in the UK. But what if your windows aren’t up to the job? It can be difficult to tell how well your windows are holding out if you aren’t a professional glazier. But it’s not impossible. 

There are a few DIY tests you can perform at home. From using a flashlight to look for homes, a burning incense stick for leaks and an infrared camera to highlight where the heat is escaping from, we’ve outlined some of the main tests you can do right here:

A windy day or one where the temperature has plummeted are good days on which to test your windows. But really, this can be done all year round. And, anyway, if there are gaps between the glass and window frame or brickwork, then now is the time to get it fixed – before the freezing-cold winter weather comes in and your heating is on as high as you can afford.

@WhichUK: “For many households, installing double glazing will mean smaller energy bills and a warmer home. In fact, 51% of people we surveyed* who have double glazing said that they bought it to make their home warmer, and 44% to reduce their energy bills.”

Incense stick test

Using a lit incense stick is a great way to look for problem gaps in your window. It’s not a case of finding holes big enough for smoke to pass through in your window. Rather it’s a case of watching the swirling motion of the smoke from the tip of the incense stick. Which way is it blowing, and in what direction? That way, you can tell if there are any drafts and leaks. If small enough, you may be able to seal some of the holes using caulk. If not, you could be looking at getting new windows fitted.

The torch test

If light can shine through from one side of the window frame to the other, then you have a problem with leaks in the frame. Get a friend to stand outside the window while you shine a torch from inside. If the friend can see a pinprick of light while the torch is on (and the rest of the lights in the room are switched off), then you may have a problem with heat escaping.

Provided the window frames look okay, then again, you might just need to seal the small gaps with caulk. Do this, and you may be amazed at the difference it can make to your energy bills (although, in these days of rising utility costs, it can be difficult to see the difference).

The infrared test

Hire an infrared camera for this test, which is best performed in very cold, preferably freezing weather. The camera will show you how the air temperature changes throughout your home when the lens is focused on it. Warm areas will show up white, orange, red and yellow. Cold areas will appear green, blue, teal and black.

The ideal colour for glass is yellow or green. If your windows show up red, orange or bright white, then you’re losing too much heat through your windows and should certainly consider switching to double glazing to prevent this.