Moved in to a new apartment (old building) in September. Now winter has come, I wake up every morning with condensed water droplets around the edges of the windows.

Wrote to the Verwaltung and simply told me to ventilate the apartment three times a day to reduce humidity and it should go away. Not only do I do that, but I also bought a dehumidifier that I turn on every day. Drops the humidity to around 45% before going to sleep.

Still nothing and wake up to condensation in the morning.

Any thing else I can do? Or should the landlord improve the insulation of the windows/install new ones?

Condensation is a good sign. Indicates that the windows are well insulated. Just open the window fully for 5 mins in the Morning. Fresh air also clears the mind.

Good to know!

Its just that, because of the condensed water on the windows, the silicone sealing is starting to have black mold stains. Surely that can't be a good thing...

One could also argue that the windows are not well insulated. Hence they are colder, which is why water vapor condenses.

Effectively there are only four ways to address this:
- reduce water vapor in the air (i.e. reduce humidity) - ventilate/dehumidifyer
- increase room temperature - this should make the "window" warmer
- increase insulation of windows (i.e. triple glazing) - this will avoid the "window" becoming cooler.
- run a towel across the windows each day.

If it is only the windows then it is less of a problem (although you can still get mold but you can generally wipe the moisture away). If you have cold walls this is much more of a problem, since then moisture gets caught in the walls.

According the renter association, it is not uncommon to have condensation on the windows during cold winter and it is for the renter to mop it up.
https://www.mieterverband.ch/mv/miet...m-fenster.html

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Oddly enough we get condensation on the only window in our place which is a bit faulty and has a slight draught.

If you have radiators, make sure they aren't obstructed by furniture, curtains or clothing to ensure the warm air can flow freely. If it's underfloor heating keep all the internal doors open to keep the air moving.

Black mould is NOT a good thing.

Would putting on a new layer of silicone sealing around the window help?

For the past two months I have been doing all the tips you have all mentioned, but still it does not improve. Like I say, when I go to bed the sensor shows a 45-50% humidity value which I understand should be more than OK.

https://postimg.cc/ctWTsJ28

Or am I just making too much of a fuss about it?

Just open the window for 5-10 minutes but be careful common sense doesn't fly out at the same time !

Do you have a Karcher window cleaner. With a soft silicon blade and vacuum action and container. Great for condensation. Or keep a very absorbent cloth in a small bucket in the bathroom, and go round all sills in morning after fresh air.

Not easy if you have to be at work early, granted.

Sorry but this answer is in the context of the OP's question completely false.
Condensations happens on the surfaces that are significantly* colder than the air in the room. In principle, this shouldn't happen, it is a sign of bad design / building, but in many cases it is hard to completely prevent.
I guess in your case, as it is around? or close? to the window frame, the frames or the contact between glass and frame are problematic. This could be due to old windows or new, low-quality windows. As at the moment outside is very cold it does not necessary mean an urgent problem (as others had indicated before me). As Mica said, just run a towel around the window.
If air is too dry, it will be unpleasant. 30-40% in the winter is ok (summers can be higher).

*this depends also on the humidity of the air, in low humidity it would not happen

Windows in my place are so airtight that condensation can not escape and therefore builds up on the window. Which by proper house design, the coldest surface. The windows are so airtight that one has first to turn the stove vent, if in operation, off before opening. Otherwise a gust of wind will come rushing in.

A rush of wind (also known as a draught) through an open window is nothing to be scared of.
It won't, contrary to Swiss beliefs, cause any medical condition normally brought on by viruses or bacterial infections.

There are, of course, varying notions of how much ventilation is necessary. When arriving here, we were taught: "Kurz und kräftig", meaning for short time, but forcefully.

1. Find the most draught-protected spot in the middle of your apartment.
2. Fling open all the windows, fully.
3. Once you can feel the cold, outside air in that quiet midpoint, you will know that most of the air inside has been replaced with air from outside. (This process can be speeded up by using extractor fans, e.g. that above the hob.) Only then close the windows.

We do this every time we get home, and usually just before we leave, too. Plus every few hours on days we're spending at home, the frequency being determined by how many people have been breathing, showering and cooking in the space, for how long.

... and of course, never be tempted to dry any washing in the flat.

yes, the airtightness is much better now, in the low energy housing with recuperating systems for heating even more.
In old houses condensation was not a problem if one had working roof and was above the ground. Those buildings were simply working differently, but also the level of comfort was much lower, the inside temperatures were low in the winter, there was constant draft.
In new houses, occasional condensation is normal; when the humidity is above normal or when the outside temperature is extremely cold. Long lasting condensation is not wanted and will shorten the life of building elements. In theory, for every element/part of the facade you have calculations that will show that this is not going to happen (under normal circumstances).

I was going to ask the OP whether they dried clothes in the apartment.

There are two aspects to their problem- those things they can do nothing about (in the short term) such as having single-glazed windows.

Then there are the things they can do something about:

• Not drying washing in the apartment
• Always using a fan extractor (if fitted) in the bathroom during/after a shower or bath.
• Always using a hood extractor when cooking - especially when boiling water.
• Using lids on saucepans when boiling/simmering
• Airing the apartment correctly

Is the condensation on every window or on windows in specific rooms?

OP, you say 'old' building - how old. And what type of windows? Are they the old fashioned Swiss double windows, eg 2 sets of single glazed windows, one inside the other? Or double glazing and how old?

Our double glazing windows are about 15 years old. No condensation anywhere to be seen- apart from 3 unheated rooms in separate guest suite- and even then, only a tiny bit at the bottom, but not enough to drip.

We live in a very well insulated apartment (Rarely use the heating, as anything that generates heat, like the oven or dryer warms the apartment), but we also suffer from condensation in winter.


I generally use my t shirt from the day before to wipe the windows before putting it in the wash. We have a dehumidifier and if we run it, during the day, in one of the rooms we wont have condensation for a couple of days.


Regarding mold, I have found the Mellerud anti mold spray to be very good, I've used it in the shower.

For your jock-itch?

I've seen a horse fly, I seen a dragon fly I seen a house fly....

I prefer proper shower gel myself, or did you mean on the shower?

Condensation only forms on cold surfaces which signify poor insulation.
Can also be a problem in newish buildings which were not properly dried out before sale.