Here is a model for a simple raised bed, sized to maximize use of a long, narrow space. Rear bed is 153" (12' 9"). Front bed is 144" (12'). One set has both beds with 17" front-to-back dimensions. The other set are 20" and 19".
The model assumes you are using standard dimensioned lumber - 2"x6" and 4"x4". This normally comes planed down to 1 5/8" x 5 5/8" and 3 5/8" square so the model is built using those planed dimensions. The model also assumes you are joining all the pieces using standard 3/8" x 4" galvanized or zinc-plated lag screws. The opposite corner of the model provides measuremets to show where 1/4" pilot holes should be drilled to allow all lag screws to be positioned without colliding with each other inside the corner post. (The pilot holes are essential if you don't want to split the rails.) Recomended materials: redwood, cedar, douglas fir, pressure treated pine. Enjoy! #garden #raised_bed #terraced