From next year, houses in the Netherlands will receive a foundation label when they are appraised. Owners of some 250,000 properties can expect a high risk label.
This has emerged from research by television program De Monitor. A high risk label can generate unexpected costs for owners who are unaware of their foundation situation.
From July 2021, appraisers will include a so-called foundation risk label in their valuation report. The Knowledge Center Approach Foundation Problems (KCAF) developed a database that can be used to determine at building level where the risks lie in the foundation. They looked at thirteen risk factors, such as height, groundwater and foundation data.
Houses are classified into five risk categories (A to E). The label includes an explanation in which category the house falls and why. Don Zandbergen of the KCAF: “A D or E label does not immediately mean that a house is about to collapse, but it should encourage a buyer or owner to investigate. It indicates that there is urgency. And that applies to 250,000 houses. ”
Over the next thirty years, one million of the more than 7.5 million houses in the Netherlands are at risk of subsiding, according to research by the Deltares knowledge institute last month. This could be due to pile rot and a low groundwater level due to increasing drought. The damage caused will not be reimbursed by insurers.
In Amsterdam, soil subsidence in combination with pile rot is a well-known problem for building foundations. The low groundwater level is disastrous for houses on wooden stilts. These must be under water, if not, they will rot and subsidence will occur.
Two years ago, the Netherlands Center for Geodesy and Geo-Informatics already warned about the consequences of soil subsidence. “Old buildings with poor foundations can subside, cracks appear in some houses, bridges are more difficult to close and quay walls also subside.”
This warning became reality at the beginning of September when part of the quay wall of the Grimburgwal collapsed. According to traffic alderman Sharon Dijksma, this was due to a combination of factors. Before the collapse, experts already stated that the canal at this place was remarkably too deep, which could have created an unstable situation.