As a non-American, what's up with this basement meme? Do American homes have furnished rooms in the literal basement or is it just a joke? Or are they like half basements with small windows?
Both are possible. Or the kid could be in the same bedroom they had since 10.
Houses built before about 1980 has basements best described as a dungeon: you store the harvest down there over winter, and the furnace is there, but you don't go down for any other purpose.
About 1980 styles started changing. Most basements in newer houses are living space - one wall might have no windows (even then there is a fire escape window large enough for that purpose that lets in useful amounts of light), but the other wall is not less than half above ground, and often entirely at grade with a complete door outside. In these newer houses there is often a complete (but small) kitchen, used only for entertaining for those rare times where the entire extended family comes to visit. There will be bedrooms down there. It isn't uncommon to have the parents live there for a few years when they cannot live alone but are not bad enough for the nursing home.
Structurally, the purpose of basements is mostly to get the foundation below the frost line so frost doesn't move the house. That can be covered by one meter or less, which leave plenty of space for windows above ground if you want to use the space. Making the space useful is pretty cheap when you have it anyway.
Note that basements are NOT universal. If there is no frost to worry about they are expensive and not worth it. If the ground water is too high there are other ways to deal with frost.
Yeah, in the US, if you have a basement, it's most often finished or at least partially finished, with walls and insulation and so on. Teenagers often like to hang out there because it offers semi-private living.
See TV shows like "That 70s Show" for a prime example.
Most basements have small windows at the top and many have light wells, where the ground outside is dug away to allow light in (and to make a place for a ladder for fire safety).
>I cannot imagine living in a windowless room, feels like a dungeon or torture room.
The vast majority, if not all, of basements I've seen in North America have their ceiling above ground level and as such tend to be surrounded with small windows.
Many, but not all, will have their own separate entrance also.
In places where it gets cold, single houses have basements (that go below usual freezing line I think). Often those are developed with bedrooms, toilets and stuff. They have small or tiny windows. Sometimes they have their own exit too (if house is built on a slope).
