one building; the same building
Used as a counter-like noun for a single building or to refer to the same building. Often appears in contexts like real estate, addresses, or describing shared occupancy.
この土地には一棟だけ家が建っている。
There is only one house standing on this land.
They live in the same apartment building.
wholesale lease of a building; renting an entire building
Compound of 一 (ひと, 'one') and 棟 (むね, 'building ridge' or 'building counter'). The reading ひとむね follows standard rendaku.