After a bit of layout work I decided I only really had space for 12 panels, even on the ground. The structure is 40’ long, with 10 post holes (4 sections, each 10’ long). The design is similar to Daox’s. Post holes are dug below the frost line and concrete poured into tubes with galvanized 4x4 post supports set into the tops. I tried to make it very forgiving on construction tolerances (post locations, lumber straightness, etc). Once the posts were set, I used lines to achieve one flat plane with fully adjustable 2x4’s along the sides of the posts. I built this over the fall of last year.