How to Banish Condensation

Droplets accumulating on your inside windows? Every property seems to suffer from this during the winter months. Condensation is widely misunderstood as a defect of the property. This blog explores how to banish condensation for good and bust some myths.

The Solution

…is ventilation. Condensation is a type of damp that causes mould. Among the damp types, it is as damaging as rising damp. So, it is important to visually take note when you see moisture droplets on the windows and start ventilating the room as soon as possible.


Usually, the most effective way is to open the window slightly or put it on the end-keep if you have a double-glazed window. See picture below:

I am not opening the window! It’s cold, don’t you know?

Yes, and this is the counter-intuitive part –

Condensation forms because someone or something in the property is emanating moisture to the point that the air cannot hold it, and forms droplets of water on a cold surface (usually, windows). You can go to town learning about “relative humidity” and “dew point” but for now, suffice it to say that the causes of condensation are the people living inside the property, pets, and even houseplants.

Here is the key…

We all want a warm and cozy home. And in order to have this, you need cooler drier air. Moisture-heavy air cannot be efficiently heated. And if you let in cooler dry air, for a few minutes each day, or every other day, not only is your room going to be warmer but the condensation problem will magically disappear. Voila!


Here are four common myths when it comes to condensation:

“We get condensation because we don’t have double-glazing”

Not quite. Any window types can get condensation because it boils down to sufficiently ventilating the room. It’s all about the air-flow. In fact, one of the most airtight ways to insulate is double-glazing and it can have the worst form of mould problems.

“We need a dehumidifier”

It’s easy to resort to this but opening the window is far more effective (and free). Even if you have a dehumidifier, the most common complaints with it are: my electricity bills are (seemingly) higher, I don’t have the time to empty the water tank, and it’s too loud for me so I can’t use it. However, if anyone really wants one, we can recommend De’Longhi DEM10 Compact 10L and Meaco Portable DD8L.

“If the property is insulated properly, we wouldn’t have this problem”

Actually, hyper-insulated homes e.g. in the loft and cavity wall, can block ventilation if installed incorrectly (very common). Again, the issue still comes down to adequate ventilation, ie, keeping the air moving in the property.

“The seal on my double-glazing window must have been breached”

This can happen, yes. But if it does, it would usually happen after a very long time (e.g. 10 years) and you will see condensation between the window glasses. If this happens, you should get the window installer’s guarantee and get it fixed for free. Otherwise, the problem is still lack of ventilation.


The best guide on condensation we’ve come across is by the Glass and Glazing Federation here.

Our favourite list of practical tips to reduce condensation is by Envirovent here. Numbers 2, 4, and 10 are the most common ways you can reduce condensation. Number 8 is really important once you have it (ie, wipe it down so it doesn’t become mouldy).

At Marybow Property, we think that property management should never be an after-thought. If you don’t have the time to look after your property, why not give us a call on 020 3588 5115? Or why not read our new page on How to Switch Agents?