We do most days upstairs, even if it's cold and wet, if only for 15 mins or so, but usually for longer I'm home a lot during the day and so can't help noticing how infrequently my neighbours open theirs. All our houses are the same with main and third bedrooms at the front so these are the neighbour's ones I see but I swear we're the only ones in our close of 20 or so houses who ever open the front windows. Even in summer, some neighbours windows stay closed. I'm clearly the odd one out where I live. What's it like where you are?