Subsidence – Vulnerability of buildings for subsidence (2019)

This map gives an indication of the vulnerability of homes to subsidence. This indication is determined on the basis of the setting sensitivity of the subsurface and the foundation of the buildings. Setting sensitivity The signaling cards Soil descent have been used for the setting sensitivity. In it, the soil’s settlement sensitivity is divided into three classes: » Non-subsoil sensitive » Soil drop sensitive » Strong subsidence sensitive An explanation of these maps is included in the layer Total maps Soil descent PZH. Foundation Detailed foundation data are not yet available at national level. The age of the buildings is available in the Basic Administration Addresses and Buildings (BAG). The age gives a first indication of the foundation type: » Buildings prior to 1950: Foundation on steel or on wooden poles. Steel foundations are particularly vulnerable to subsidence, but old pile foundations can also be vulnerable. Poles that are not deep enough can sink in the soil (negative adhesive). Before 1950, pine wood was often used instead of pinewood. Pine is more susceptible to bacterial damage, even if it is not dry. » Buildings between 1950 @-@ 1970: From 1950 onwards, it was usually first probed to determine the suitable foundation type and pile depth. The foundation was therefore better than before 1950, but during the reconstruction the building quality was generally worse than after 1970. » Buildings after 1970: Houses and poles are basically of good quality. Vulnerable premises for subsidence Based on the setting sensitivity and foundation indication, the buildings are divided into three classes: » Not or hardly vulnerable: — All premises on subsurface with class Non-Soil Descent Sensitive — Premises from after 1950 on subsurface with class Soil descent sensitive — Buildings from after 1970 with class Strong Soil Descent Sensitive » Vulnerable: — Premises from before 1950 on subsurface with class Soil descent sensitive — Premises from 1950 to 1970 on subsurface with class Strong Soil drop sensitive » Very vulnerable: — Premises from before 1950 on subsurface with class Strong Soil drop sensitive