## 1 Introduction
Therefore, this research paper focuses on a case study in Romania within a project of high scientific value aiming at the improvement of energy efficiency in buildings of the Politehnica University Timisoara. The study investigates the identification of energy inefficiencies and proposes energy-saving solutions for reducing the carbon footprint of existing structures. By the methodology starting from the data collection process to the future utilisation of Building Information Modelling--Existing Conditions Model (BIM-ECM) as a foundational tool, the research specifically addresses the challenge of inadequate energy performance data in legacy buildings. Through BIM-ECM-based simulations, discrepancies between design parametersand actual operational energy consumption, subsequently exploring and recommending retrofitting strategies, optimised building management systems, and renewable energy integration to achieve quantifiable carbon emission reductions and enhance overall building sustainability can be realised. Initially, we frame the necessity of this study within the context of ongoing projects funded by European grants, which focus on the sustainability and rehabilitation of buildings constructed in the 1970s-1980s. Subsequently, we propose a working methodology developed by the authors, which includes field data collection using modern and distinct methods and models, processing and interpretation of the obtained data, as well as their preparation for future integration into Building Information Modelling (BIM) for thermal evaluation of the studied buildings. Contribution of the USE-REC Project in the Sustainability Objectives of the United Nations' Agenda 2030  
The \"University Students Engaging in Responsible and Sustainable Energy Consumption--USE-REC\" initiative [8] represents a strategic push for the promotion of responsible and sustainable energy practices. The initiative is distinguished by its holistic approach to cultivate a culture of energy consciousness among students at Politehnica University Timisoara. The essence of USE-REC is to combine energy efficiency improvements in student accommodations with participatory student initiatives, thus generating a collective commitment to sustainability. The aim of the project is to encourage the mobilisation of students to promote energy-efficient behaviours to lead community change and contribute significantly to global efforts to reduce greenhouse gas emissions. In line with Politehnica University's broader sustainability objectives, which echo the United Nations' Agenda 2030 [9], the project emphasises an integrative approach to sustainability that spans education, research, governance, and everyday campus life. It prepares students for autonomous living in an era that demands judicious resource utilisation and upholds the principles of intergenerational and intragenerational equity. On the other hand, the increasing imperative to mitigate anthropogenic climate change and reduce energy consumption has driven a significant trend towards the integration of bio-architectural principles and ecologically sustainable design methodologies within urban and building construction paradigms [10]. Therefore, having the student's dormitory according to new EU recommendations and regulations can be a good practice example for the next generations of engineers. Implementing this project within the university's dormitories marks a pivotal advance toward establishing a green campus ethos in Timisoara, demonstrating a deep-rooted commitment to environmental stewardship and sustainable development that resonates with the values and aspirations of the students. The projects' key objectives are to:  
1. Identify energy losses,
2. propose solutions for energy efficiency, and
3. reduce the carbon footprint of student accommodations from the Politehnica University Timisoara. By using two methods for data collection (methods that represent in themselves two technologies and two approaches), an innovative character is given to the workflow.