Necessary room

Four bedrooms and a necessary room upstairs and one down, a formal dining room, a large parlor ...

At various times, that place also has been called a privy chamber, a necessary room, the smallest room in the house, and even “where the queen goes alone.

Master baths are as big as a real room, spacious and a decorator's dream, more than a necessary room.

She had a sleeping chamber complete with a necessary room attached and a hot tub in the corner.

... near the main hall in a small room that might have been a necessary room. It's probably someone relieving himself.

The beach hut provided shelter from the sun, a place to change, and a necessary room.