部屋を散らかす
へやをちらかす to litter a room (with things)

部屋を暖める
へやをあたためる to heat the room

部屋を空ける
へやをあける to clear a room

部屋代
へやだい room rent

部屋住み
へやずみ an adult-age eldest son who has yet to come into his inheritance (a young adult still) living at home a dependent

部屋割り
へやわり assignment of rooms

部屋着
へやぎ dressing gown loungewear