sofa design, couch, sketch

How to Make a Couch

One of the most basic pieces of furniture in a home is a living room sofa. Yet for many couples starting out, buying this piece of furniture can be a bit of a challenge. Sofas aren’t exactly cheap and a couple starting our usually doesn’t have much of a budget to work with.

One really great solution to this problem is to make your own. While making the kind of upholstered sectional sofa that you might see in your local furniture store is a bit of a challenge, you can actually make a simple sofa, rather easily. All you need is a little plywood, some cushions and some imagination.

There are actually a number of different ways you can design and build your sofa, but we’re going to go with a simple design. Then I’ll talk a bit about how you can modify that design, to make yourself a fancier sofa.

You’re going to want to use good quality plywood for this. Plywood that has a lot of voids or cracks in it isn’t going to look very good, even if it is cheaper. So look for either marine grade plywood, applewood, or a cabinet-grade plywood. If you can, ask them if it is guaranteed to be without voids. The three types I just mentioned usually are, but they may not be guaranteed void-free.

Basic Sofa Design

If we break it down, the most basic sofa design consists of four pieces, all of which can be cut out of ¾ inch thick plywood. Those four pieces are:

  • The seat
  • The back
  • The two ends or supports

The tricky part of this is getting the dimensions right. So, let’s start out by looking at the essential dimensions for a standard sofa.

sofa design, couch, sketch
Basic sofa design

The critical dimensions in the drawing above are:

  • The back of the seat is 18” above the floor, but is angled upwards 5° towards the outer edge
  • The seat is 24” deep
  • The back of the sofa is angled backwards 15°
  • The back height in the drawing is 26”, but sofa backs vary considerably in height

Everything else in the design is predicated on trying to come up with those final dimensions. Please note that the dimensions that I’ve given are for the seat at the top of the cushion, not at the bottom. So if you are making a sofa with cushions, you need to adjust the seat height and depth to accommodate the thickness of your cushions.

Making a Simple Sofa

The simplest sort of sofa can be made by cutting two end pieces out of plywood, per the dimensions in the drawing above. Then cut two strips of plywood, 24” wide by however long you want the sofa to be. Simply screwing those two pieces onto the ends would provide you with a sofa.

Of course, there would be a little more detail to making it than that. One important thing would be to round all your corners and edges, so that nobody would get scratched or hurt on your sofa. You will probably also want some sort of cushions, whether that means to cushion the seat and back itself or to make cushions that sit on the seat and back.

One important consideration for your sofa is how much support you have to provide. If you are just making two end pieces, as shown, you will be limited to a sofa that’s about four feet long. To go any longer than that, you would either need another end piece, to act as a center support, or you would need to cut strips of plywood (roughly 2” wide) and attach them perpendicularly to the seat bottom, one at the front and one at the back, to act as supports.

Modifying the Basic Design

Maybe you don’t like this sofa design. After all, there are a lot of different styles of sofas out there. Okay, so how can we modify this basic design?

Adding Arms

The first modification we could do is to box the ends of the sofa. In this we would not cut out the seat of the sofa, as low as shown in the drawing, but rather cut it higher. How much higher is more a question of styling than anything else, but if we want arms, it would be roughly nine inches higher. Then, we’d need to add some support pieces, on the inside of the ends, for the seat to attach to.

If we want wider arms, we can accomplish this by either adding a strip of plywood about three to four inches wide, attaching it to the top of the existing arm, perpendicular to the piece, so that it sticks out to the sides. This would provide us with a more comfortable arm, as well as somewhere to set a drink.

Most commercial furniture goes farther than this for the arms though, actually making the ends of the sofa boxes, with an inner and outer layer. The top of this box then becomes the arm of the sofa. It can either be finished wood or upholstered, as you desire.

Adding Legs

The other basic way of modifying the sofa design is to add legs, in place of having the ends go all the way to the floor. In this case, we’re going to cut some of the bottom of the existing ends off, so that they won’t reach the floor when we finish assembling the sofa. We can do this with any of the arm designs I just discussed.

If we want to add legs, we should probably box in the bottom of the sofa, or it might not look right. This isn’t a complete box, but rather only a lip on the front, giving the appearance of a box. The bottom of the ends and the bottom of this lip should meet up and be even. This is essentially the same as what I was talking about to provide support for a sofa longer than four feet.

The other thing that should be done is to add piece of wood, hidden behind this lip and under the sofa seat. These need to be perpendicular to the lip and the same distance from each end. The purpose of these two pieces is to give us something to attach the legs to.

While it is possible to make your own legs, the easiest thing to do is to buy pre-made legs from your local home improvement center. Check the various different ones, as they will carry different styles. These can be attached to the framework under the sofa, providing a different look.

Upholstering the Sofa

There are two basic ways of upholstering the sofa, depending on what you want. Most of the time, sofas are upholstered with cushions. In fact, it is rare to see anything else. These cushions are fairly easy to make, as all they are, are blocks of foam rubber, with a covering of upholstery fabric.

If you have basic sewing skills and access to a sewing machine, you can make your own cushions. Typically, these have “piping” along the corners, to help hold the covering in place and make the cushion appear more squared off. That piping is available from any upholstery supply. It is covered with a strip of the same fabric as you are using to cover the cushions.

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