wooden floor; room with a wooden floor
Refers to a floor made of wooden boards, or a room that has such a floor. Often contrasted with tatami rooms.
The living room in this house has a wooden floor.
I laid out the futon on the wooden floor and slept.
changing room (at a public bath)
Specifically the changing area in a public bath (銭湯) or similar facility, which traditionally has a wooden floor.
I undressed in the changing room of the public bath.
板の間 is a room with a raised wooden floor, the traditional counterpart to 土間's unpaved earthen floor.
Compound of 板 (ita, 'board') + の (no, possessive particle) + 間 (ma, 'room' or 'space'), literally 'board room'.