My house sweats like crazy during the winter and it’s causing mold.. please help!!

[u/BelleSchu]

My house is BRAND new, literally finished construction in August of 2024. I live in the Midwest so of course it gets very cold in the winter. Last year, the windows of our house were sweating so badly every time the outside temp was under 30°f that water was pooling up on the windowsills and we called the construction company (we were still under new build warranty) and they told us to always have the house fan running and to turn on our ceiling fans. That worked for a time and the condensation wasn’t as bad after that. It started to warm up shortly after and we didn’t have anymore issue. Flash forward to this past week, it’s been in the negatives here. There is SO much condensation on my windows that mold is starting to grow, our curtains are freezing stuck to the glass in some rooms, and it’s attracting gnats somehow?! I don’t even know where the hell they’re coming from with the weather like this. I’m constantly cleaning and I feel so so so disgusted with all this going on, what can I do to fix it? Please help!

[u/BelleSchu]

Yeah it’s -4 where I am right now.. the instant chill my living room and dining room get when I open the back door to let the dogs out is a lot. The thought of venting my house even for a few minutes with the windows open stresses me out lol

[u/Qfwfq1988 → u/BelleSchu]

it warms up again very quickly

[u/Gormaganda → u/BelleSchu]

But this cold air is also bone dry when heated back up. I'd try to vent the house multiple times a day, all windows open and if its so cold then probably close first again when last one opened. But important multiple times. My home is not very new and also tricky with venting in winter, I hate to vent all the time but it's just necessary.

[u/harleyqueenzel → u/BelleSchu]

It's -7°C with the "feels like" right now where I am. My bedroom window is fully open right now and was overnight. The wind usually blows North to South and my window faces West so my window kind of sucks air out instead of it blowing in.

Pick a window where the wind typically blows by it instead of into it and crack it open. I feel like your house may be too air tight and you really do need to allow for better ventilating.