DIN 4020 complements the European specifications of DIN EN 1997-2 at national level. It is therefore only applicable in conjunction with DIN EN 1997-2 and its National Annex DIN EN 1997-2/NA. The aim of both DIN EN 1997-2 and DIN 4020 is to ensure that the structure, composition and characteristics of the subsoil are already known at the design stage and during the tendering procedure for a construction project. Geotechnical investigations and testing conducted in accordance with DIN EN 1997-2, DIN EN 1997-2/NA and DIN 4020 are required for the safety checks specified in DIN EN 1997-1, DIN EN 1997-1/NA and DIN 1054.