Replace a closet door with a bookcase door. Great idea to hide the water heater. No more ugly, never touched water heater door.
Hide keys, etc. I really like this idea for spare keys, either by the front door or in the kitchen, mud room
Built-In Planter Ideas Projects, Ideas and Inspiration! Including, from garden club london, this gorgeous modern built-in planter idea. - Gardening For You
This Victorian remodel has a chic industrial edge. Internal steel-framed windows and doors act as a transparent screen between the living and eating spaces. The walls are a smart on-trend grey.
Oak sleeper at the corner (and it functions as a raised bed too) - Verbena bonariensis Anna Wardrop garden.