The research and the bill both belong to the stone high wall. The Adobe wall is a skin of it: learn that blueprint, craft at a Level 2 bench, and if the skin is yours, the walls come out in clay brick. No scrap goes into a blueprint of its own.
Everything else carries over too. A craft still makes three walls, so count the ring in threes, and each craft still eats one sheet metal that only loot and the recycler hand you.
Nothing in the rows differs, and the game calls it a high stone wall, so the choice is looks. Plan the ring together with the Adobe gate, or the one grey gate becomes the thing everybody notices.
Questions
High External Adobe Wall ×10: how many resources?
Sheet Metal ×4, Stones ×16,000.
Which workbench does High External Adobe Wall need?
Workbench level 2.
How long does High External Adobe Wall take to craft?
25 s for one, every step included.
How much scrap does researching High External Adobe Wall take?