Modern Wood Storage Sofa

Build two rectangular 2x4 frames for the arms with the 2-1/2" self-tapping screws. Check each for square before the screws go tight — an out-of-square arm throws the whole sofa off.

Clad the outside faces with 1x8 and 1x6 boards using glue and 1-1/4" brad nails, then add the 1x6 trim to finish the edges. Set both arms aside.

Build the two seat frames from the 102-1/2" rails and the 9" cross members, using the 2-1/2" screws. These frames carry the drawers, so they must match each other exactly. Lay them side by side and confirm the cross-member spacing lines up frame to frame before you move on. A frame that's out of parallel means a drawer that binds later.

Build the back frame from the two 102-1/2" rails and three 21" studs, checking for square and using glue with the 2-1/2" screws.

If the sofa backs against a wall, splice the 1/4" plywood over the center stud (two pieces, 24" x 51-1/4") and attach with glue and 1-1/4" brads. If the back will be exposed to the room, leave it open for now — you'll clad it with 1x boards instead in the next step.

Stand the arms up and attach the back frame to them with the 2" screws, driving from the inside where the heads won't show. If the back is exposed, add the extra 1x cladding boards now with glue and 1-1/4" brads. Check that the whole carcass sits flat and square before the drawers go in.

Set the 15°-mitered 1x8 back boards inside the back opening and nail them down. Run the 1x2 retaining strip across the base of the back boards with glue and brads to lock them in place.

Trim the front and top edges of the whole sofa with 1x3 and 1x6 using glue and 1-1/4" brads. Fill nail holes and sand everything smooth before finishing.

Build four drawer boxes from 1x6 sides and fronts/backs with 1/4" plywood bottoms, sized to fit the openings. Mount the 26" slides so each drawer front sits flush with the front edge of the 2x4 frame. If a slide won't reach because the opening is a touch wide, block inward with scrap wood — that's normal and expected on a rough-framed carcass.

Attach the 1x10 drawer faces from inside with screws and glue, predrilling so the face doesn't split. Adjust each face for an even gap before the screws go tight.

Lay scrap 1x boards (about 23" long) across the seat frame as slats and nail them down — they carry the cushion, so they don't need to be pretty.

Assemble the black iron pipe rail from the flanges, elbows, and tees, and screw the flanges to the back to hold it. Finish the wood, then drop in a cushion sized to the finished seat opening.