They don't require holes to be drilled to fix them to the wall, which is ideal in a rental where you may not be at liberty to do something with more permanence, or simply if you're indecisive and like to rearrange your furnishings at whim. Tricky nooks, such as the hollows either side of a fireplace, can be turned into feasts for the eyes when snugly filled with a unit that's the perfect size. Not only useful for sitting rooms, studies and bedrooms, they can become handy additions to your hallways and ‘provide invaluable extra storage for wine glasses and cookery books in a kitchen.