Sleeping on a sofa occasionally will not do it any harm. Sleeping on it on a permanent or long-term basis can result in wear and tear, and you may find that eventually some parts are affected more than others.
It depends on the height and weight of the sleeper and the position in which he sleeps, as well as whether bed linen is used between the sofa and the sleeper. The upholstery of the sofa may also sustain damage, and fabric-covered sofas may require frequent cleaning which will reduce the lifespan of the furniture.
Sagging Cushions
The seat cushions are likely to sag in the places where the body weight is greatest on a regular basis. In a sleeping position, the greatest weight is around the hips and middle body area, and this is likely to cause the center seat to sag faster than the sides. This can also be a result of inferior cushion material that breaks down with use.
Depressed Foam
Areas where pressure is placed on the foam padding of the upholstery on a regular basis may eventually remain depressed, unless it has a high “recovery factor,” which is a reading based on the indentation force deflection standards used by the foam industry. These areas could include the arm rest of the sofa, where the sleeper puts his head and possibly his feet, and the lower back rests, which are not intended for the partial weight of a sleeping body.
