You can distinguish between someone who's paying for a room and paying for an apartment or house with lodger versus tenant.
Is it possible to distinguish between someone who offers a room for rent and offers an apartment or house for rent? Are there any hyponyms for "landlord" that make this distinction?
I checked onelook.com's reverse dictionary, and the thesauri recommended on meta, and didn't find anything.
Well tenant is the antonym of landlord.
From Oxford English Dictionary (OED):
landlord, n.
Originally, a lord or owner of land; in recorded use applied only spec. to the person who lets land to a tenant.
tenant, n
One who holds a piece of land, a house, etc., by lease for a term of years or a set time. (The ordinary current sense. Correlative to landlord.)
Lodger would also strangely be the closest antonym for lodger.
From OED:
lodger, n.
One who resides as an inmate in another person's house, paying a certain sum periodically for the accommodation.
One who lodges a person; a host. Obs.
Renter may also apply, depending on how the word is used:
renter, n
A person who collects rents (esp. those belonging to a corporate body), taxes, or tribute.
Or host:
host, n
A man who lodges and entertains for payment; a man who keeps a public place of lodging or entertainment; the landlord of an inn.
The word that comes to mind is homeowner, and this source uses it in the context you mention.
In this discussion of boarding-house on Wikipedia (yes, a less-than-authoritative reference) the persons renting are referred to as lodgers. The operator is referred to as landlord. The term rooming house also seems to be used interchangeably.
While I have never seen such usage, the terms boarding-house keeper or boarding-house owner (or rooming house keeper or owner) would seem appropriate. It should be noted that boarding-houses and rooming houses usually provided some meals, and that is not suggested in the original question.
Lessor is the word for somebody who leases something, which is a more general and impersonal term than landlord/-lady.
It seems, though, that the words "lodger" and "renter" might be used meaning the opposite things, depending on the conext, while the words "landlord/landlady or lesser" and "tenant" are far less ambiguous...
