Condensation on a window

How to Prevent Condensation on Windows

If you look in almost any tenancy agreement on a rented property, you’ll most likely find a short piece explaining that condensation is up to you to control and advising you to keep your windows open when possible to avoid this problem.

Although it cannot be completely avoided, this article explains why condensation occurs and how to act fast before it creates mould growth.

Why does condensation occur?

When warm air meets cool air, its ability to hold moisture is reduced forcing the moisture to, instead, transfer to a cooler surface and this forms condensation. This is best demonstrated in the winter, when cold external temperatures are combined with the warmer temperatures inside your home.

Why is condensation a problem?

Condensation itself is nothing to worry about, it’s a natural process and no matter how well ventilated your home is, you’re still going to have some encounters with condensation. What can cause problems, however, is the condensation on your windows streaming onto the wood frames around the window. If the condensation continues to build up on your frame it could encourage mould growth.

How do I control condensation?

There are many ways to control condensation. The most obvious of which is to increase the ventilation throughout your home. Improving air circulation with fans (when appropriate) and using exhaust fans while cooking or showering will help to reduce the amount of condensation build up. Another way to do this is to simply open your windows for a few minutes each day.

If you can’t leave the windows open, consider buying a dehumidifier. This will reduce the humidity level in your home, helping to reduce condensation. You can measure humidity with a hygrometer so you’ll know when it’s down to the right level.

Another less obvious change that you can make to your home, is to dry clothes outside whenever possible as according to, just one load of washing emits two litres of water into the air. (Crazy, right?)

Growing plants on your windowsill will also cause condensation build up on your windows so try to keep plants outside as often as you can.

If you think plants are the only culprits here, then you’d be wrong. Any living thing that’s inside your home will be producing excess moisture. Yes, that includes you! The room in your home which is used the most should be well ventilated as this is where your condensation will be occurring the most often.

Closing doors can save you a lot of problems with condensation. When you’re taking a shower, for example, closing the bathroom door will stop steam travelling to other (colder) rooms.

If you are still concerned about the condensation build up in your home, it’s best to contact your landlord and talk about your worries. They may be able to give you some tips that they’ve picked up from previous tenants over the years or book for a maintenance worker to come and take a look.