A room is a 2D footprint — width and depth matter for placement, plus the walkway gap left between the item and walls or other obstacles.
- Place the item footprint inside the room rectangle in the orientation it will be used.
- Compute walkway gaps from each item edge to every wall and to other obstacles in the room.
- Take the minimum walkway gap — that’s the daily-traffic clearance the room must support.
- Verdict ladder (getRoomVerdictTier): walkway <18 in DOESN'T_FIT; 18–24 VERY_TIGHT; 24–36 TIGHT; 36–48 FITS; ≥48 confident FITS.
Walkway thresholds use standard ergonomic minimums; a confident mover may negotiate gaps tighter than the recommended tier.