How to Make a Wood Sofa

Arrange two 1 1/2 by 3 1/2 by 18 inch boards on the working surface with their largest surfaces facing downward. Set the boards parallel to each other and about 12 inches apart. Position two additional 1 1/2 by 3 1/2 by 18 inch boards on top of them, perpendicular to them and arranged in a square so that the ends overlap. Adjust the spacing to that the corners of all four boards are even.

Drill two holes through each top board corner and into the board below, for a total of eight holes. Set 2 1/2-inch wood screws in these holes and tighten them completely. Repeat this process with two more sets of four 1 1/2 by 3 1/2 by 18 inch boards to complete three total couch leg sections.

Stand the three leg sections up on their ends, parallel to one another about a foot apart. Set four 1 1/2 by 3 1/2 by 48 inch boards on top of the three leg supports, evenly spaced so they overlap the first and last leg support evenly. Adjust the spacing of the long boards, which will form the couch seat, so that the rear seat board is flush with the rear of the leg supports. Adjust the other seat boards so they are evenly spaced with the front seat board flush against the front of the leg support boards.

Drill two holes down through each seat board and into each leg support board it touches, for a total of 24 holes. Set 2 1/2-inch wood screws into each of those holes and fasten them down tightly with a drill.

Position three 1 1/2 by 3 1/2 by 36 inch boards against the rear of the couch with the help of an assistant. Set the largest surface of each board against the rear of a leg support and the seat boards, so that it sticks up about 24 inches above the seat board. Drill six holes through each of these boards, which are the rear boards, and into the leg supports and seat board. Set 2 1/2-inch wood screws into these holes and tighten them completely, securing the rear boards.

Have an assistant hold four 1 1/2 by 3 1/2 by 48 inch boards against the rear boards, perpendicular to the seat boards and evenly spaced on the rear boards. Drill two holes through each of these boards, which are the backrest boards, and into each rear board, for a total of 24 holes. Set a 2 1/2-inch wood screw in each hole and attach them together with a drill.

Position a 1 1/2 by 3 1/2 by 10 inch board in each corner of the seat, with its largest surfaces facing front and back. Drill two holes up through the seat boards and up into the bottom of these boards, which are the arm rest support boards. Secure the arm rest support boards in place with 2 1/2-inch wood screws put in the holes and tightened securely.

Lay a 1 1/2 by 3 1/2 by 18 inch board across each pair of arm rest support boards to serve as the arm rests. Drill two holes through each arm rest and into each arm rest support board. Secure the arm rests in place with 2 1/2-inch wood screws.