Kominka are not defined by the period they were built or how old they are, but usually the term is used when referring to houses built before the World War II, and especially to those built before the Taisho Period.
古民家の定義に、どの時代に建てられたものか、あるいは建造され何年を経たものを指すかの定義はないが、通常戦前以前のもの、特に大正以前のものをさす場合が多い。