The paper contains results of long-term settlement monitoring of historic buildings in St. Petersburg. Based on results of repeated surveying, statistical processing of settlement rates of more than 2300 historic buildings was performed. Basic conclusions are drawn as to distribution of maximum settlement values throughout the city area. Also, the paper contains settlement monitoring results for 30 buildings constructed on soft soils in St. Petersburg (monitoring period extending from 23 to 77 years). Basic conclusions as to the character of settlement development are offered alongside primary comparisons of monitoring results with engineering methods of settlement calculations. The analysis thus performed is necessary for development and verification of engineering calculation methods, as well as of numerical rheological models of subgrade behaviour.