3D model of IKEA BILLY BOOKCASE | DESIGNER: Gillis Lundgren | Adjustable shelves; adapt space between shelves according to your needs.A simple unit can be enough storage for a limited space or the foundation for a larger storage solution if your needs change.It is estimated that every five seconds, one BILLY bookcase is sold somewhere in the world. Pretty impressive considering we launched BILLY in 1979. It’s the booklovers choice that never goes out of style.