The purpose of work was to submit proposals and specify the methodology used in the determination of technological losses in transmission of steam and heat, which are recognized in the regulated heat supply activities as normative technological losses (regulated costs). General calculation principles of overall heat losses of the methodology for the determination of technological losses of heat and steam supply pipes, and the assumptions used by the National Commission for Energy Control and Prices were verified in this work. The assumptions used were extended after the assessment of the structures and materials of the centralized heat transfer networks in Lithuania. Limitations of the spreadsheet submitted by the Customer were determined and suggestions on how to improve the spreadsheet were formed. The spreadsheet was updated in accordance with the proposals and expanded for calculation of heat losses of steam piping. Suggestions for the further application of the methodology for determining the prices of heat were developed.