The article is devoted to the development of approaches to assessing the energy efficiency of capital construction facilities in the context of climate change. The traditional approach is limited to estimating the internal energy consumption of buildings, without taking into account the nature and origin of the energy resources used. The authors propose to introduce the concept of energy-carbon efficiency, which allows us to develop a standard approach to energy efficiency and combines an assessment of the energy consumption of a capital construction facility, taking into account the carbon footprint created during energy generation. The study analyzes current Russian regulatory documents, and reveals a lack of an integrated approach to energy efficiency assessment, which does not take into account regional differentiation in energy generation sources. Since Russia is divided into eight zones with different types of electricity generation, the authors emphasize that the same type of facilities located in different zones may demonstrate a similar level of energy efficiency, but significantly differ in the level of carbon footprint. The proposed concept of energy and carbon efficiency will allow for a comprehensive analysis of the impact of a capital construction facility on the environment, taking into account the regional factor. It is concluded that it is necessary to develop new rules and regulations that encourage the implementation of low-carbon practices in the construction and operation of facilities. The study offers a solution to an urgent task—achieving comprehensive consideration of energy efficiency and environmental safety requirements in the context of combating climate change.