## 5 Conclusions  
This paper presents an overview of current knowledge on the development of BIM and DT techniques and their application areas. The collected information was analyzed in the context of the possibilities of its potential application in the technologically and functionally developing field of networked building automation systems integrated with IoT solutions. In this review, the authors discuss the directions of development of these solutions and models, as well as presenting their new trends and possibilities. In accordance with the preliminary diagnosis, assumptions, and objectives for this review, as outlined in Section 1, the analysis identifies gaps and potential barriers and obstacles to the advancement of the concept of synergies between BIM and DT methodologies in the design, construction, and operation of buildings with innovative BACS functions and services. These functions and services are oriented towards enhancing building comfort, improving energy efficiency, and facilitating the implementation of novel dynamic energy and infrastructure management mechanisms. As these processes are based on standardized guidelines (EN ISO 52120 and SRI), it is possible to describe them in BIM models as well as DT algorithms and patterns and, as a result, realize them using advanced tools for modeling, prediction, monitoring, and effective control of automation in buildings. As the authors note, this is of particular importance at the current time, when building infrastructure is becoming increasingly complex and multisystem. Furthermore, buildings equipped with RES and energy storage are becoming active participants in smart grid systems and the energy market as prosumers. This necessitates a shift in the methodology employed for the design, construction, and operation of buildings, particularly those equipped with BACS and BMS with IoT technologies. This is to develop universal and useful tools to support designers, installers, users, and maintainers. In this context, the authors formulated the theses of the original contribution concerning the possibilities of effective and constructive use of the EN ISO 52120 standard guidelines and the SRI, which can be effectively and constructively employed as integral parts of BIM and DTs in for contemporary buildings, both newly constructed and retrofitted. To meet the new standards, the market requires tools that accelerate work, thereby enabling the formulation of intelligent functions. An additional aspect is their operation and monitoring of parameters at every stage of the building's existence. It is for these reasons that the authors focus on a tool that could revolutionize the market and streamline many existing buildings, the DT. In particular, this concerns the technical and functional organization of BACS with distributed IoT networks, supported by cloud services for more accurate models, DT patterns, and parametric settings for control and management functions. Finally, this paper develops a conceptual framework for the application of BIM and DTs in these areas, identifies challenges and necessary research directions, and outlines perspectives for new technical and tool solutions. Future Research Objectives and Work  
In light of the findings and preliminary conclusions presented in Sections 2-4, and considering the challenges associated with the potential expansion of BIM and DT tools for the technical and functional design of BACS and BMS systems in buildings, the authors propose a number of key research objectives and directions for future research. These focus primarily on overcoming the barriers and gaps identified in this review. Here is their synthetic summary:  
* A multitude of communication and data processing protocols have been developed for both categories of tools, with the majority of these protocols being developed independently by different entities. The effective cooperation of BIM and DT tools is necessary for the implementation of advanced functions and services of BACS and BMS systems.