A sleeper sofa is one of the most tempting pieces of furniture to consider buying, especially when living space is at a premium. A good sleeper sofa appears to cover several needs at once -- it provides comfortable seating for the den or living room while doubling as a spare bed for guests. Few other pieces of furniture can claim such duality of purpose.

Before you invest in a sleeper sofa, there are some things to consider. One inherent problem with a combination sofa and bed is that it rarely performs both tasks equally well. There may have to be some compromises made in exchange for versatility. It may help to consider what a sleeper sofa's primary function would be in your particular home environment. Some consider a sleeper sofa to be a couch first and foremost, with the added bonus of emergency bedding. Others may consider the bed to be just as important as the sofa, since it will be the main bed in the home. Before shopping for a sleeper sofa, know what your particular priorities are.

As many amateur movers have discovered, a sleeper sofa can be surprisingly heavy. The folded bed frame, springs and mattress add significant weight, so you may want to consider allowing professionals to move it into your home. Some furniture stores may charge an extra fee for this service, so ask first. Otherwise, plan on enlisting the help of two very strong volunteers. It's also important to measure the dimensions of the sleeper sofa and the planned route into your home. Many older sleeper sofa models were built to different scales than today's narrower apartment complexes and townhouses. You might be able to remove the legs for added clearance, but sometimes furniture is simply too big for the proposed space.

Before buying a sleeper sofa, it pays to test out the bed. Pull the bed frame out several times to make sure the mechanism is solid and reliable. Sometimes a used sleeper sofa will have noticeable damage to the frame or springs. Lie down on the mattress as you would any other bed. Many people dread sleeping on a sleeper sofa because of the thin mattress and the legendary support bar. High-end models may have much thicker mattresses and a redesigned frame to eliminate the need for the traditional backbreaker. You may have to invest in additional padding or an air mattress if your sleeper sofa proves to be uncomfortable. Some guests may actually prefer to sleep on the sofa instead of the fold-away bed. Again, deciding on your particular priorities beforehand may help you find a comfortable sofa, a comfortable bed or hopefully a combination of both.