The problem of constructing additional storeys on existing buildings is really up-to-date nowadays. Implementation of the above-mentioned process should be undertaken after the inspection of constructions. Foundation is the construction which takes additional loads. The inspection of constructions, which are located underground, i.e. piles, is a very complicated technical problem. This article considers the full inspection of the pile foundation, analysis of mistakes in the geological survey and ways of their elimination. The results of determining a bearing capacity of piles were described using three different methods: calculation, static penetration test, in-situ load tests were compared. The paper shows the essential difference between the results obtained by using different methods. The analysis of the survey’s results contributes to drawing up recommendations on the methodology of the pile foundation complex inspection.