Build a platform using garden pavers, bricks, or blocks. While a typical stone garden sofa may be made out of rocks and mortar, using pavers of a standard shape and size will make your life far more easy. Just build up a platform with the pavers that are approximately 3 feet deep, 2 feet high and 5 feet wide.
Build back and arms. Use the pavers to build the sides and back of the sofa. Make the arms and back of the sofa about 6 inches deep and 4 feet high on the back and sides.
Test your stone garden sofa to make sure it is the right size and height for the people will be using it. Make adjustments to make it more suitable for you.
Take apart and re-build your stone garden sofa, this time adding mixed cement to permanently hold the blocks, or pavers in place. Continue to build up the sofa in the same way you would pave with bricks.
When the sofa is build up with pavers, bricks, or blocks, use the concrete to cover the blocks, completely hiding them and creating a smooth surface for the sofa. It may take some time and patience to build up the layer of concrete until you are satisfied