Homeowners Professionals

Condensation and your windows

We want our homes to be warm and cosy havens, a place where we can relax, spend time with family and get a good night’s sleep. But sometimes, the heat produced by our heating systems and the moisture that’s naturally created in our homes can begin to cause issues, such as damp and even black mould. If you’ve noticed that condensation has begun to appear on the inside of your windows, particularly in winter, you may want to find out why and how to get rid of it. While condensation is usually quite easy to do away with, it can sometimes be a sign of an issue with your windows. Read on to find out more about condensation and your windows.

Why do my windows have condensation on the inside?

Before you can begin to get rid of the condensation, you first need to understand the cause of it.

What causes condensation?


Humid air is air that contains water. Typically, the warmer the air is, the more moisture it can hold. This means that a warm and cosy home could contain more water vapour than a home that is colder or doesn’t have a heating system.

When this warm, humid air comes into contact with cold surfaces, the air is unable to hold onto that excess moisture and so it is deposited onto the surface in the form of water droplets, or condensation.  

The image above demonstrates how humid air can travel around your home and become stuck - it has nowhere to go.

Lack of ventilation

Ventilation is really important in our homes. It’s the reason why we have cooker fans, extractor fans, air bricks, air vents, trickle vents and windows that can open. If our homes were completely sealed with no way for the air inside to move around and be replaced, the air quality would be very poor and could result in headaches, dizziness, tiredness and breathing problems.

You should ensure that you frequently ventilate your home and remove as much humid air as possible. You could open your windows for a few minutes every day or make suitable use of extractor fans to pull the humid air outside.


While we’ve just explained that you need to properly ventilate your home to prevent condensation on your windows, a draughty home can be just as bad. When this is the case, too much moist air can come in from outside and cause damp. If you think that a particular window is the culprit, the condensation will appear around that window first, so check for leaks or broken seals.  

How to get rid of condensation inside your windows

If you’ve just noticed that there is condensation on your windows, or the problem is worsening, there are some things you can do to stop this issue altogether.

Ventilate your home

As humid air is the most common cause of condensation on the inside of your windows, the best thing to do is ventilate your home to get rid of as much humidity as possible. You could use a dehumidifier or simply open some windows for around 10 minutes each day, even in winter.

You should also do everything you can to prevent unnecessary moisture from being produced. Putting wet clothes on radiators to dry, for instance, will create lots of water vapour that can quickly spread through the house. When you cook pasta, the water in the pan boils and eventually becomes hot enough to evaporate, producing excess steam. You may notice that the windows begin to fog up when you’re cooking. This is caused by the extra hot   and humid air. You could reduce this by placing a lid on the saucepan and reducing the heat so the water boils more steadily.

You can make use of extractor fans in both your kitchen and bathroom, and in some instances they are required as part of building regulations when there is no openable window within the same room. These help to pull the humid air out of your home and can help to  prevent issues such as damp and mould.  

Improve the air flow

You may also be able to prevent condensation by improving the airflow around your home too. If you sleep with your bedroom door closed, for instance, the humidity in the air can increase as you expel water vapour when you breathe. Instead, try to sleep with the door open so that the vapour can leave the room and spread equally through the rest of the property.

Warm air rises too, which means that the condensation might be worse on your windows upstairs than downstairs.  

Check the window’s seal

Double glazed windows are made up of two panes of glass that have a substantial gap between them. This gap is filled with gas, usually argonargan, that acts as a kind of insulator to prevent too much heat from passing through the glass and outside. Then, the whole unit is sealed to prevent the gas from escaping. Over time, these seals can weaken and may fail altogether. When this happens, condensation can appear between the panes of glass.

This kind of condensation is difficult to get rid ofbad, andas it usually means that you will need to get the whole window replaced. The excess moisture won’t go away no matter how much you try to remove humidity or ventilate the room. However, as a first step, you should call a glazing professional to take a look at the window. They may be able to re-gas the window and replace the seal that’s broken without needing to install a new window.  

How can we help?