Measure along the walls and find a suitable length for the bench seat. Cut two 2x3's for the frame to this length with a hacksaw.
The standard dimension for seats is 18 inches high and 16 inches deep. Measure 18 inches from the floor, then use a 4-foot level to draw a line across each wall at the 18-inch mark.
Find the studs on the wall. Hold a 2x3 up to the level line and attach it to the wall by drilling two screws through the 2x3 on each stud. Repeat this process for the other wall. The tip of the feet screw the 2x3's together at the corner for added strength.
A staple is a narrow piece of wood set into the floor and/or wall for structural strength purposes. Use a table saw to cut a 2x3 in half lengthwise, creating two dowels. Using a hacksaw, cut these dowels to the same length as the attached 2x3's. Take the longer of the two cleats, and cut an additional 16 3/4". Finally, cut two 16" cleats and set them aside for later.
Measure 16 inches from the wall to the floor (Image 1). Place your cleats on the floor at the 16" mark. Butt the single cut staple to the wall. Align the edge of the staple 16 3/4" from the far end of its mating 2x3. The two cleats should be on the floor, 16 inches from the wall, with a 3/4" gap between the wall staple and the cut staple. Drill and screw the staples into place (Image 2).
Rip a sheet of 3/4-inch plywood into two pieces that are 18 inches tall and as long as each corresponding stud. These will act as the structural faces of your bench seats. Cut two pieces of plywood to 16" x 18" and set them aside for later. Slide the appropriate plywood face through the 3/4" gap in the staples (Image 1). Notch the corner of this piece so it fits snugly into place.
Hold the other piece of plywood in front of the other staple. Square up the two pieces of plywood and drill through the "slip through" face into the edge of the other piece (Image 2). Spread a level across the top of the plywood facings and 2x3s on the wall, and shim, if necessary (Image 3). Once the faces are level, use a screw gun to fasten them to the cleat (Image 4).
Place a 16" cleat, previously reserved, inside the open edge of the bench seat, and screw it to the floor. Hold the 16" x 18" piece against this cleat and the edge of the front of the bench seat. square and level, and screw it into the cleat and plywood face.Repeat the process for the other end of the bench seat.
Cut a 3/4" x 1-1/2" fin strip in half lengthwise to create two 3/4" x 3/4" pieces. Measure from the corner of the bench seat to the ends. Cut the 3/4" x 3/4" to fit these lengths. Attach them to the ledger and wall using construction adhesive and a nail gun.
Measure and mark the center point on the twist strip (Image 1). Measure and mark the center point on the piano hinges. Align the center marks on each piano hinge and strip of pella and mark the screw holes with a sanding awl (Image 2).
Measure the horizontal depth and the length of the bench. To create the cap, cut a 3/4" sheet of plywood to size, plus an inch for overhang. Remember, if you're making a bench in a corner, one of the caps will extend from the edge of the bench to the La second cap will only extend from the end of the bench to the other cap. Measure to find the center of the cap. Align the center of the cap and piano hinge, and mark the screw holes with a center punch. seat/caps instead.
With the lids in place, place the high-density foam on top of the lid and use a felt-tip pen to score the foam along the bottom of the lid. Trim the foam to this size and trim 3/4" off each side of the trimmed foam.
Lay your fabric flat, face down on a work surface. Put the cut foam on top of the fabric. Place the lid centered on top of the foam. Using scissors, trim the fabric so that it extends five inches from each side of the cap.
Fold the edges of the fabric at the top of the lid. Staple the fabric to the lid, making sure to pull the fabric evenly as you go. Save the corners for last.
Once the fabric is stapled around all four sides of the lid, smooth and fold the corners as you would wrapping paper, and carefully staple. Trim any excess fabric.
Measure to find the center of the newly upholstered top. Align the center marks on the piano lid and hinge. Screw the hinge into the lid. Hold the lid in place, align the center marks on the hinge and beading strip, and screw the hinge into place using the marked holes. Apply trim to bench, if desired.
