I was going to post exactly this :-) I live in a 5 year old apartment, and there are two units above and below exactly the same layout. We don't turn on our hea

I was going to post exactly this :-) I live in a 5 year old apartment, and there are two units above and below exactly the same layout. We don't turn on our heating until it gets well below freezing as the heat from other apartments is more than enough. This season the coldest temperature I've seen is 20.5c - when it was 0c outside and cloudy for one week. For vertical neighbours you could say they could have insulated the ceilings (when we bought the apartment new it was unfinished, just concrete inside), so it was their choice to allow heat to escape. But we have underfloor heating, so it's not just neighbours vertically but also horizontally, as quite a lot of heat transfers via the concrete floors too (this is the only way the common areas of the building are heated) - you can't insulate that. In the summer we have AC on, and a lot of our neighbours don't have it, so I figure we benefiting them at that time by taking away some of their heat. On a related note, if you have underground parking I'd also suggest to choose the lowest floor if you have a choice (as long as there is no flood risk). We are on -2 and when it's 35c outside our car is parked in a cool 18c, and when it's -25c it is 8c.