The ability to design water supply and drainage systems for residential buildings is important for a construction engineer. However, the current educational-professional program is paying insufficient attention to the formation of the relevant professional competencies. The author of the article has divided the software used in the design of water supply and drainage systems of residential buildings into four groups: general-purpose graphic editors, specialized graphic editors, mathematical packages, automated design tools. It is concluded that the optimal training of students in the design of water supply and drainage systems is the use of the EDraw graphics editor and spreadsheets MS Excel in view of their simplicity and functionality. In the process of designing water supply and drainage systems for residential buildings in the EDraw environment students develop skills: to perform basic operations with files in the EDraw environment; build floor plans (at home); depict pipelines on the floor plan (at home); to determine the rational places of placing of sanitary-technical devices; to construct axonometric projections of water supply and drainage systems of residential buildings. In the process of performing calculations in the MS Excel environment students develop skills: to perform basic operations on cells and tables; write formulas using absolute and relative links to cells; apply pipeline calculation methods recommended by the State Construction Standards in the design of water supply and sewage systems; to critically evaluate the results of calculations and to make adjustments to the performed calculations. The article presents the results of a pedagogical experiment conducted at the Glukhiv Agro-Technical Institute of Sumy NAU during April-October 2018. The results of the experiment were proved by means of mathematical statistics.