How does soil shrink cause foundation damage?

Ground shrinkage, moisture, and the build-up of subsidence risk

Soil subsidence tied to climate change follows a straightforward physical chain: when ground dries, some soils—especially those that can change volume with moisture—shrink. That shrinkage can reduce the support under buildings’ foundations, allowing the ground beneath to move unevenly.

As the soil volume changes, foundations experience stress they weren’t designed for. The result can be gradual movement (often recognized through cracks or misalignment) or sudden worsening when conditions intensify—such as extended hotter, drier spells.

A London-area analysis highlighted this drought-driven pathway, linking subsidence risk to “hotter, drier weather” expected to worsen with the broader climate crisis. The key is that heat and dryness don’t just affect the surface; they alter near-surface moisture regimes that control ground behavior.

Why it matters is that subsidence can be highly variable across a city. Even neighboring streets may have different risk profiles depending on soil type and local conditions that influence moisture retention and drainage. That means mitigation and monitoring need to be targeted rather than one-size-fits-all.

In practice, the climate mechanism implies that periods with reduced rainfall and higher temperatures raise the odds of shrink-swell cycles strong enough to move foundations. Over time, repeated stress can accumulate, increasing the likelihood of structural impacts.

What the climate-driven mechanism implies

• Heat and drought increase soil moisture deficits
• Shrinkage can pull foundations downward or create differential settlement
• Risk is spatially uneven, so mapping and local monitoring are crucial