https://steamcommunity.com/sharedfiles/filedetails/?id=2968888842

I built my own vertical ladder, at least one that will allow me to go up 3 meters to the next floor.

One cannot climb player-constructed vertical walls, either stone or wooden. One can, however, attach one-meter horizontal wooden beams to an existing wall to provide hand- or footholds so one may scale a vertical wall. One must use the same sprint-jump technique one uses to scale very steep slopes.

Upon reaching the upper floor, one must jump off to the side. It takes a bit of practice. The game uses the same animation it uses when scaling very steep slopes.