Sofa frame and general furniture construction is a very important factor in upholstery and upholstered furniture. Most people look at a beautifully upholstered sofa or armchair and do not see what lies beneath it. The same is true of a human being. The external appearance of a person is determined by the muscles that lie beneath the skin. These muscles are no stronger than the skeletal bone structure upon which everything else is built.
The skeleton of a sofa or a chair is its wooden frame. We are discussing traditional furniture here, not items fashioned from tubular steel and synthetic foam cushions. A sofa frame must be solid in order to bear the stresses and strains involved when it is put to use. For a sofa to be comfortable, it must be able to tolerate these stresses without sagging.