Question: is a walk in closet considered a room

Answer: Yes, A closet (especially in North American usage) is an enclosed space used for storage, particularly that of clothes. ``Fitted closet'' are built into the walls of the house so that they take up no apparent space in the room. Closets are often built under stairs, thereby using awkward space that would otherwise go unused. A ``walk-in closet'' is a typically a very small windowless room attached to a bedroom, used for clothes storage.