The study developed and tested a mathematical model for assessing the sustainability of urban engineering infrastructure based on aggregating indicators of energy consumption, carbon emissions, and operating costs. Three scenarios for the operation of engineering infrastructure were analyzed: traditional, partial, and full digitalization. The impact of digital transformation on changes in the overall sustainability of infrastructure systems was examined. It was found that the transition to digital management models allows for a reduction in the environmental burden and operating costs. The distribution of loads between various infrastructure components was examined: water supply, energy, transport, housing and utilities, and communications. It was determined that the greatest potential for improving sustainability is observed in the water supply and energy sectors. It was established that the digitalization of transport infrastructure and housing and utilities produces significant benefits even in the early stages. An integrated sustainability assessment methodology with the ability to be scaled and adapted to the conditions of specific territories was developed. The paper proposes using an aggregated index to substantiate modernization priorities and build digital decision-support platforms. The model's application in strategic management of sustainable urban development in the context of the digital economy is substantiated. The proposed approach is recommended for use in monitoring and validating public infrastructure policy. The calculated indices enable the development of sustainable development scenarios that take environmental priorities into account.