That's an unusual requirement, in my experience. Check the precise language in your By-Laws. In many cases, there's no restriction on directors at all. In other coops - such as ours - a director must be either a shareholder or the spouse of a shareholder.

If it just says "resident," that seems ambiguous. Obviously a person would be eligible if it's their primary residence, and not eligible if they're subletting and not living there at all. But what about all the situations in between? Someone with a summer home where they spend three months a year? Someone who plans to sublet two months after the election? Someone who says they're a primary resident but the NYC records do not reflect this (a very common problem)? There's no clearly correct answer.