Best placed in the South
The south takes a staircase well: it is a heavy direction and the tradition wants mass here. The turn should be clockwise going up.
What the South governs
South is Yama’s direction, and it carries weight rather than light. The tradition builds it up — heavy walls, storage, mass — and keeps openings modest.
Where the Staircase belongs
A staircase is mass and movement together, which is why the tradition treats it like structure rather than circulation. It belongs in the heavy half, turns clockwise, and never sits over the centre of the plan.