This article presents a developed design method applied in an actual structure (St John's Church, Tartu, Estonia) during the process of extensive underpinning. The article focuses on a practical theory of how to implement soil-foundation-pile interaction using pretested, end-jacked piles and how to design a strip foundation using only one method based on ultimate limit state (ULS) and serviceability limit state (SLS).The method takes the following into account as geotechnical requirements: contact pressure, total settlement and angular distortions. As far as structural requirements are concerned, the method considers admissible plastic rotations, end movements due to displacement angle, as well as control of cracking.