According to halakha, the mezuzah should be placed on the right side of the door or doorpost, in the upper third of the doorpost (i.e., approximately shoulder height), within approximately 3 inches (8 cm) of the doorway opening. Care should be taken to not tear or damage the parchment or the wording on it, as this will invalidate the mezuzah, which is considered Torah. Generally, halakha requires that mezuzot be affixed within 30 days of moving into a rented house or apartment. This applies to Jews living in the Diaspora (i.e., outside of the Land of Israel). For a purchased home or apartment in the Diaspora, or a residence in Israel (owned or rented), the mezuzah is affixed immediately upon moving in. The reason for this difference is that there is an assumption that when a Jew lives in Israel, Israel shall remain his / her permanent residence, whereas a home in the diaspora is temporary. Mezuzot are very special objects and must be taken care of carefully and according to Jewish laws and traditions.
where does a mezuzah go on a door
on the right side of the door or doorpost, in the upper third of the doorpost (i.e., approximately shoulder height), within approximately 3 inches (8 cm) of the doorway opening