What Is Subsidence — and Why It’s a Foundation Risk Subsidence occurs when the ground beneath a building sinks or shifts, causing the foundation to move. Common signs include diagonal wall cracks, sticking doors or windows, and uneven floors. It’s a serious issue that requires prompt action to prevent further structural damage. Subsidence can be caused by several factors: Soil shrinkage from dry weather or nearby trees Leaking drains or groundwater washing away soil Poorly co