Cut the wooden deck boards to size according to the cutting guide.
Seal the edges of the wood to prevent cracking.
Wood glue the support boards together and clamp, allow time for the wood glue to cure.
Drill pilot holes through the support beam piece. Drive screws through the piece for extra support.
Cut out the notch in the wood using the cutting guide for reference.
Construct the legs layer by layer using wood screws and pilot holes. Add the support beam and the smaller layer pieces on the last layer.
Use the sofa cushions as reference for how long the back rest pieces should be.
Construct the back rest using pilot holes and wood screws.
Sand the back rest and base pieces of the couch in preparation for staining.
Apply stain to the sofa and allow time for the stain to dry.