If you go up the stairs on any of these 4 buildings (https://map.projectzomboid.com/#0.5706406766065583,0.32954950144012896,76.67519984894946) the "roof" (or hill, don't know exactly what that is) won't let you see part of the screen.
Also, most of the metalwork recipes that require metal scraps don't actually consume any. Here's a list of them: fence, wired fence, big wired fence, big pole fence, fence gate, big pole fence gate, big double pole gate, double fence gate, metal roof. Only metal shelves and metal crate consume scraps on each use. (40.26)