In the Netherlands, there are more than 8 million residential buildings. Around half have been built before the 1970s. The foundation of these structures consists mostly of timber piles or shallow foundations. The Dutch knowledge center for existing foundation problems and solutions, KCAF, has estimated that the foundations of about 1 million current structures are sensitive to damage (KCAF, 2022), the degree of the which varies from minor (small cracks) to severe damage (large differential settlements, collapse). Natural degradation of materials with the catalyzing effect due to climate change, soil subsidence, additional (pile) load, and water management policy choices are the main causes of these growing foundation problems. The related costs of the reinforcement and replacement of current foundations (to prevent severe damage) are expected up to be as much as 60 billion Euro until 2050 (Deltares/ TNO, 2021). The reuse and extended use of current foundations is more urgent than ever. This is not only relevant to save costs and to prevent unsafe conditions, but also to reduce the CO2 footprint related to the reinforcement and replacement of current foundations as much as possible. A correct and ambiguous foundation assessment is essential to this process. This paper describes the current Dutch approach of foundation assessments and classification, based on different available (Dutch) codes and guidelines, including the updated KCAF guideline ‘Inspection and assessment of existing foundations’ (KCAF, 2022). ; Paper presentation