The efficiency of the economic functioning of any facility largely depends on the ability of managers of various levels to carefully prepare and justify the decisions made. The conditions of the market (competitive) economy put forward serious. In solving the problem of increasing the economic efficiency of the construction of engineering networks, a special place belongs to design, in the field of which scientific and technical achievements are implemented, which determine the technical and economic level of construction. The article examines the theoretical and methodological principles of designing engineering networks, which are aimed at improving the procedural and instrumental basis for making project decisions and justifying measures to optimize the management of engineering networks in the conditions of dynamic changes in construction projects requirements for the quality, timeliness, completeness, reliability of economic information, depth of analysis of economic indicators. The interaction of the construction of new utility networks and the economy is very important for the fulfillment of the tasks of the economic strategy, which are related to capital construction. Current problems of creating a modern design automation system (CAD) of engineering networks are considered in order to ensure the effective use of the resources of the target product, which, even at the design stage, allows to take into account the possibility of expanding or reconstructing the system in case of the addition of new consumers of the target product. network The paper proposes a new approach to the design of modern systems of automated design, which allows the use of CAD to solve the problems of external and internal design of network systems. The tasks that are solved at the stages of external and internal design are formulated and specified. The key task of external design is to find out the fundamental possibility of creating a network according to the desired properties that satisfy the imposed restrictions. Internal design includes the synthesis and analysis of the network being designed. It is shown that the CAD of engineering networks can be represented as a set of methodological, informational, software, technical and organizational support, and a general diagram of the interconnection of CAD tools at the stages of engineering network design and operation has been developed and researched.