Avoiding excessive moisture in your apartment: here's how (2026)

Cooking, showering, washing clothes – many domestic activities create moisture. There are a number of things you can do to ensure that they do not cause mould to develop in your home. Our tips and tricks will enable you to avoid excess humidity in your apartment and ensure a pleasant room climate.

Topics

At a glance

Excessively high moisture levels can cause mould to develop – and damage both your health and your apartment.
Regularly airing rooms and heating your flat correctly are the most important measures for avoiding excessive moisture in your home.
Small areas of mould should be removed immediately using household remedies. The removal of larger patches of mould is a job for professionals.

What gives rise to moisture in apartments?

Moisture is created during everyday activities like brushing your teeth, showering or cooking. However, we also give off water vapour simply by breathing and sweating. If excessively humid air is not able to escape to the outside, moisture will collect on cold surfaces like windows and exterior walls.

Over time, this creates a bad atmosphere in the room and can cause mould to develop. This problem mainly affects poorly ventilated rooms and new-builds.

What are the consequences of excessive humidity?

Over time, excessively high humidity can affect both your health and the building materials in your apartment:

Health risks: Mould often thrives in moist environments. It can cause allergies, breathing problems and skin irritation.
Damage to the building: High moisture levels can damage walls, furniture and the building materials in your home. Metal rusts, wood swells up and wallpaper comes unstuck. In addition, damp walls lose their insulating effect, which will cause your heating costs to rise.

Good to know

Wenn sich an kalten Oberflächen, wie beispielsweise am Fenster, Tropfen bilden, ist dies ein erstes Warnzeichen für zu hohe Luftfeuchtigkeit.

How can you avoid excessive moisture in your home?

There are various ways of avoiding moisture problems in your flat and reducing the humidity levels if they are too high:

Air rooms correctly – in short sharp bursts rather than leaving windows tilted open

When condensation forms on windows, this means that the humidity levels are too high. In this case you should air the room straight away – and properly:

Leave the window wide open for five to ten minutes several times a day. If possible, open several windows at the same time in order to create a draught. Known as "cross-ventilation", this method ensures that the air in the rooms is optimally replaced. Moisture does not stand a chance.
Airing rooms in short, sharp bursts is ideal as it enables the moisture to escape without cooling the room down excessively. Leaving windows tilted open often has the opposite effect: the room gets unnecessarily cold, which actually promotes mould formation.
Position furniture at least six centimetres away from exterior walls. This enables the air to circulate better and reduces the amount of moisture that accumulates.

Optimal heating for a dry room climate

Not only does having the right room temperature help to prevent excess moisture; it also reduces your heating costs. You should bear the following in mind:

The temperature should be 20 to 21°C in living rooms and studies and 16 to 18°C in bedrooms.
Do not turn the thermostat below level 2 as this can cause the walls to get too cold.
Thermostats can jam if left unused for long periods in the summer. To prevent this from happening, you should also adjust them regularly in the summer

Reduce the moisture created by cooking, showering and drying washing

Use the extractor fan when cooking and air the kitchen well afterwards.
Open the bathroom window – if you there is one – or switch on the ventilation system after showering or bathing. Leaving the bathroom door open can also help. Dry wet surfaces with a cloth.
If possible, do not dry washing in living areas.

Additional tip: clean elastic joints regularly

Also known as grout lines, elastic joints are used in all areas that regularly get sprayed with water, such as the shower, the bath or around the kitchen sink. They perform an important sealing function, but they are also prone to accumulating dirt and mould. For that reason, it is important to clean the joints regularly, ideally with soapy water or vinegar cleaning solution. You can also use a grease removing agent in the kitchen. Broken joints should be repaired as soon as possible. If you live in a rental apartment, the management agency will take care of this.

What should I do if moisture or mould has already accumulated?

Sometimes, moisture will accumulate in your apartment despite all your precautions. In a worst-case scenario, mould may already have developed To prevent the damage from getting any worse, you need to act quickly. Here's what you should do:

First steps for tackling visible moisture

Wipe away condensation on windows every day to reduce the moisture load.
Dry damp walls and furniture straight away by ventilating rooms well and heating them correctly.
Check whether mould has formed behind larger items of furniture such as chests of drawers and cupboards.

When should I inform the management agency?

If you discover structural defects such as window leaks, poorly insulated walls or damp cellar walls, you should contact the management agency straight away.
Large areas of mould are usually a serious problem. Report them to the agency immediately so that it can obtain a professional assessment of the situation.
Patches of moisture and peeling paint or wallpaper are warning signs that should not be ignored. You should also inform your management agency if you notice any of these.

Professional mould removal

If you discover large areas of mould or have recurring issues with it, you should inform your management agency straight away. Mould spores that are not correctly removed will spread.
After the mould has been removed, you should carefully analyse what is causing the elevated moisture levels in your apartment so that you can take appropriate steps to prevent mould from forming again.