'narrow room' is correct and usable in written English.
It is used to describe a room which is small or has limited space. For example, "He entered the narrow room, feeling a bit cramped in the tight space."
Caesar's narrow room was at the front, facing N Street.
Fidyka lives in a narrow room on the second floor.
His young daughter greeted us and led us into a long, narrow room.
The toilet and shower are in a separate, extremely narrow room.
Servers bustled purposefully through the narrow room, balancing enormous trays of food on one shoulder.
Inside was a narrow room with perhaps eight tables, most already filled.
The mirror in our narrow room was shaped like a guillotine.
The Aastha office is a narrow room on top of a two-story walk-up.
Mirrors along both walls give the narrow room a spacious feel.
I wrote the opening chapter in a long, narrow room in our house in Sussex.
The receptionist led me through a warren of cubicles to a narrow room looking out on the parking lot.
