房里 = 房 (room) + 里 (inside) — a location phrase, not a single lexical word. The 里 is unstressed (neutral tone). Equivalent to 房间里, just shorter and slightly more colloquial/literary.
usage
Mostly seen in narration and fiction. In speech you'll more often hear 屋里 or 房间里 in the north and 房里 in the south or in subtitled drama dialogue.
