There’s a very interesting question that was brought down by Rabbi Akiva Eger Z"L in his Teshuvot. We know the Mitzvah of Mezuzah is an obligation on the dweller of the house. Which means, a person can have a house but he is not obligated until he begins to dwell in it. The Gemara calls that Chovat Hadar. The obligation is on the dweller. Just because you own a house, it does not obligate you on Mezuzah. The obligation starts once you begin living in the house.

So Rabbi Akiva Eger has a question. A person put up his Mezuzot and made a Beracha. And now he goes away on vacation, for example, for the summer. The person is therefore is out of his house for about 65 days. Is he required to make the Beracha again upon returning home? Is he required to take down the Mezuzot and remount them? There was a lengthy time period that he was away, and now that he came back, he is not sure if he leaves it alone or performs one or both of the acts mentioned above. Rabbi Eger leaves this question unanswered and does not resolve it.

However Rav Chida in Birke Yospeh also discussed this question, and he said that the Chachamim only made a Takana (ruling) to make the Beracha at the time of putting them up the first time. And it is not considered an Hefsek (interruption), since he has intention to move back. Since this is only a temporary vacation and he is planning on coming back, so then it is assumed that he had Kavana to cover all those situations when he made the Beracha.

There’s also another opinion by one of the Rishonim called the Dimuke Yoseph, that holds that even though a person is not in the house, once he puts it up, he doesn’t have to make another Beracha even though there was an interruption. And that is the Halacha.

Therefore if someone goes away and comes aback after the vacation, even though nobody was in the house, he does not have to put any Mezuzot, nor does he have to make another Beracha.