Step 1: Measure, Materials
Find a chair that's a comfortable height and depth, take those measurements and apply to your bench. This bench is 18" tall(top of seat) and 18" deep(wall to front lip).
Measure your desired length on both walls and to save some clean up, use painter's tape to mark wall measurements.
Step 2: Prep
Remember to leave room for the trim you'll be putting on the boxes to fit behind the wall trim.
I had my trim paint color matched at Lowe's and they did a great job.
I placed my bench right on top of the flooring.
Step 3: Base
Put the bases in place, use 3" screws to fasten to wall and then place plywood cut to fit on top.
Step 4: Risers and Top Frame
Add the base, plywood, top frame, and top board and subtract from your overall height to get the height of your riser boards.
They should be About 9 3/4" -10 1/2" depending on material used.
Cut all your risers and construct your top frames. They should mimic the base frames. Risers will screw through plywood into base frame perfectly fine.
If doing a corner bench like this, remember to screw both base and top frames together for consistency and rigidity.
Step 5: Paneling and Molding
Cut the panels so that when the corners meet, they don't create a void. Make the side edge of one piece meet the front edge of the other. I hope that makes sense.
It basically means some of your pieces will overlap the side.
This is the same for the molding.
Use an air nailer to connect paneling and molding. Adhesive can be used, it's a personal preference.
Step 6: Top Plate
Once it's cut out I routed the edges that will be behind the knees and on the edge. Not where the two boards meet or the wall side of the board. It was just a round over route on top and bottom to help avoid a sharp lip.
Remember to cut out a sliver of trim for the top to hide where the wall and top board meet. Mine was 2.5" of the MDF I had with 45 degree notches on the end.
Step 7: Top Board and Finishing
Once dried go over with a hand sander with 220 grit.
Wipe all surfaces with a damp rag to clean up sanding leftovers.
Tape all walls and floors and paint with semi gloss paint to help make it easy for wiping and cleaning.