A house needs to have Mezuzos on every doorway that is an entrance to an appropriate room. The question I have is: is each Mezuzah a separate Mitzvah on it's own, or do they all combine to one 'larger' Mitzvah of having a properly Mezuzahed house?
Possible Nafkah Minahs:
- You have a house with 10 doorways that should have Mezuzahs, but only have 8 Mezuzahs. If each one is a separate Mitzvah, then you would likely put up what you have. If it's one larger Mitzvah, maybe there is no need to.
- You are doing construction on your house, and have the option of constructing certain doorways either in ways that obligate one it in a Mezuzah, or in ways that exempt it from a Mezuzah. If each doorway is a separate Mitzvah, maybe one should make as many doorways as possible obligated in Mezuzah.
- You don't have time to put up all the Mezuzos for your house at one time. Instead, you put them up on two separate occasions. If they're each separate Mitzvos, each distinct time you put up Mezuzos requires a new Bracha. If it's all one Mitzvah, perhaps you should only say the Bracha before the last batch that you put up.