Let me first say that there are reasons to buy a less expensive, lower quality sofa but my goal in shopping and with the info below is to help you buy a sofa that will last.
So let's start at the beginning...the frame. Go with solid wood. Plywood and particle board (often held together by staples) will not hold up as well. And when we are talking seating support the best quality options are the eight-way hand tied spring system or sinuous springs. You will also see web suspension which is not always bad but less superior to the first two. And finally, when talking construction, is the filling. There are many different kinds of filling - down, down blends, spring wrapped foam and polyurethane - which I just listed from most expensive to least. What matters the most is that if you don't go with down, which is pricey, you want to focus on getting a high density foam which will last longer then a lower density foam. But above all sit down. Be sure you sit on a couch before you buy it and remember the floor model is often a little more worn then what you will get right away but over time this is what your sofa will feel like.
The next thing to consider, which was my main focus, is fabric and honestly what really matters...cleaning that fabric. So here is the big secret, that changed my sofa buying life. Upholstered furniture has a fabric cleaning code on the tag and if you speak the right language you can decode any information you need.
So let's translate...
"W" means water soluble. And yup, you guessed it, this means you can clean this piece with water. Now don't go grabbing the garden hose. No sofa will do great soaking wet. But you can use water based cleaners or foams and an upholstery / carpet cleaner using the attachments. This is the most durable fabric but not always the most glamorous.
"S" means solvent cleaner only. Basically this is the equivalent to "dry-clean only". This must be cleaned in a water-less process done by a professional. So my recommendation if you go for a "S" fabric is make sure the covers are removable. Then you can easily take them to the dry cleaners when needed.
"SW" means water soluble / solvent. This piece is best maintained if dry-cleaned but can be spot cleaned with a water based product if necessary. And if a water based product is used do your best to dry it as best you can.
"X" means exactly that...it cannot be cleaned! You wont see "X" very often anymore but this code means the piece can only be vacuumed. Um, not what I would recommend for really any sofa at all unless you plan to cover it in your grandma's best plastic ;)
So I really hope this information was helpful. It may not apply to you right now but remember to read it again next time you head to the furniture store. In addition to helping you make a smarter purchase it also makes the need for an overly pushy sales person to answer your questions less essential. You can answer all your own questions!
Oh wait, don't go! One more pic of a um interesting sofa...
