TT #52 · Parashas Va’eschanan · Passuk 6:9
And you shall write them on the doorposts of your house and on your gates.
Torah Temimah points to the exemption of bathhouses / tanneries / etc. (structures not built for honor) and the status of a rented house.
English: One might have thought even a privy, a tannery, a bathhouse and a immersion-house? The verse says “house” — just as a house is made for honor, these that are not made for honor are excluded. A rented house is exempt from mezuzah, as it is written “on the doorposts of your house” — your house, and not a rented one (biblical exemption; rabbinic obligation may still apply).
Diyuk of “bayis” as a structure of honor, and of “beisecha” as excluding a rented house on the biblical level.
Bathhouses, tanneries and similar non-honorable structures are exempt; a rented house is biblically exempt (though a rabbinic obligation may still rest on the occupant).