Airy, spacious and versatile, open-concept living rooms are a popular design choice for the modern home, but a successful scheme requires careful and considered planning. Whether you’re after a sprawling, sociable hub for the whole family or a multitasking setup in a small city apartment, we’ve rounded up the best-kept design secrets to help you transform an empty interior into a warm and welcoming living space.  If you want to create carefully defined living areas within a free-flowing space, don’t be afraid to give different functional zones radically different personalities. In this contrasting scheme, the kitchen features moody grey plaster-effect walls, dark wood furnishings and coordinating appliances