When choosing a futon sofa bed, make sure that it will fit well within the intended space when it is both open and closed, think about whether it will spend more time in one of these two positions, and consider its aesthetic qualities. General comfort is also important to consider. A futon sofa bed should be comfortable to sit on and to sleep on, so be sure to test it out in both positions before making a purchase. Also, consider the weight of the futon sofa bed and how easy it is to open and close. A very heavy futon sofa bed can be difficult for a single person to manipulate.
One of the most important factors is space. If a futon sofa bed is meant to fit in a den that doubles as a guest room, it should fit well in that space as a couch or as a bed. Before purchasing this kind of futon, take measurements of the space in which it must fit and then compare those measurements with the measurements of the futon. In addition to fitting into the space, it is best if there is also enough space for people to walk around the perimeter of the futon sofa bed after it has been transformed into a bed. If the futon sofa bed will only be used as a bed on a very occasional basis, then it may be all right if it causes the room to be a bit cramped when it is in the open position.
When shopping for this kind of futon, also consider the aesthetics of the room in which it will be installed. There are dozens of futon frame designs and even more colors and patterns that can be used to upholster the cushion. A modern room might look very good with a futon that has a metal frame. A rustic room might look nice with a futon that has a wooden frame.
Consider also the predominant colors of the room in which the futon will be installed. After all, the upholstery on on futon sofa bed will create a wide swath of color within the room. A bright or deep color can be chosen to make the futon sofa bed a focal point in the room. Alternatively, a muted color can be chosen to help the item blend in to the room.