Drought resulted in 425,000 homes with foundation damage: Deltares

Cracked wall - Credit: - License: DepositPhotos Tech Nature Thursday, 8 October 2026 - 08:36

Around 425,000 homes in the Netherlands currently have foundation problems or are likely to develop them soon due to the recent drought, NOS reported, based on calculations by the research institutes Deltares and TNO. The Knowledge Center for Foundation Issues (KCAF) expects this figure to rise to around 687,000 homes within 30 years due to climate change.

According to Otto Levelt, a land subsidence expert at Deltares, homes with shallow foundations on clay soil are particularly affected. Drought causes clay soil to shrink. With shallow foundations, this shrinkage can extend beneath the house, leading to cracks in walls or stuck windows and doors. Repair costs can run into the tens of thousands of euros. Homes built on stilts, as well as those on peat or sandy soil, are also at risk.

Homeowners tend to bury their heads in the sand when it comes to foundation issues, KCAF director Frank van Lier told the broadcaster. “Yet 30 percent of houses affected by these problems could be saved through prevention.”

There are preventative steps available, Levelt of Deltares added, such as covering clay soil to prevent it from drying out so quickly. “We also think drip irrigation around the house could keep the soil moist. And, of course, building deeper foundations is crucial.”

“But we do need to build in a climate-resilient way,” Levelt stressed, pointing out that climate change makes prolonged dry spells interspersed with heavy downpours increasingly likely. That puts many types of homes at risk.

“A house with a shallow foundation built on soft soil will sink closer and closer to the groundwater,” he said as an example. That can lead to dampness and mold, or flooding during downpours. Low groundwater levels could also expose homes on stilts to pile rot, making them unstable.

The Dutch Authority for the Financial Markets (AFM) previously calculated that it would cost around €11 billion to repair all homes with foundation problems. While some homeowners can bear these costs themselves, approximately 75,000 cannot.

VEH, the advocacy group for homeowners, is calling for government support. “Of course, the government cannot always foot the bill, but the uncertainty is currently immense due to the costs facing some people,” Simon Vrijsen of the VEH told NOS. “As a homeowner, you have no control over the causes, nor can you insure yourself against them.”