Energy efficiency in buildings: EPC and SRI as enablers of future renovations

• Mixed-methods approach combined surveys, interviews, and field work. • Surveys confirmed strong demand for training, BIM, and smartness tools. • Use-case analysis translated SRI results into concrete EE and DSM measures. • Problem tree mapped drivers, core EPC/SRI issues, and consequences. • Objective tree translated barriers into goals and SMART policy targets. In line with European climate-neutrality goals, buildings are increasingly understood not as static, isolated structures, but as active components of a wider built environment that also includes energy and transport infrastructure. This shift highlights the need for traditional, static Energy Performance Certificates (EPCs) to evolve into more dynamic and holistic instruments. Future EPCs are expected to assess not only the building envelope and technical systems, but also the performance of key subsystems such as automation and control technologies, and their interaction with the external environment. In parallel, the Smart Readiness Indicator (SRI) has emerged as a complementary tool designed to evaluate a building’s ability to respond to occupant needs, improve energy efficiency, and support grid stability through demand response signals. However, despite their relevance, EPCs and SRI are not currently reaching their full potential, revealing an important research and policy gap. This paper provides an objective analysis of EPC and SRI, examining their respective strengths, weaknesses, and possible roles in shaping future renovation programmes through a case study of Slovenia. A mixed-methods approach was adopted, combining qualitative and quantitative techniques to explore the complex dimensions of EPC and SRI implementation and impact. To identify key challenges and opportunities, a problem tree is developed, highlighting barriers such as inconsistent implementation, performance gaps, and limited stakeholder engagement. Based on these findings, an objective tree is proposed, outlining policy interventions and measures to improve the effectiveness, usability, and integration of EPC and SRI in future building renovation strategies.