
A systematic translational mapping comparing smart readiness indicator (SRI) and BACS standard (EN ISO 52120-1) under EPBD 2024 recast
Abstract
The recast Energy Performance of Buildings Directive (2024/1275) introduces two frameworks for assessing smart building capabilities: the Smart Readiness Indicator (SRI) and the Building Automation and Control Systems (BACS) standard efficiency classification defined in EN ISO 52120-1:2022 (hereafter ‘BACS standard’). Both apply to large non-residential buildings with an effective rated output for heating or cooling systems above 290 kW and are linked to digital building logbooks under Article 16 of the EPBD. However, the methodological compatibility between the two assessment systems remains unclear, particularly regarding how they measure energy efficiency and compliance with regulatory standards.
This study compares the SRI and BACS standard across nine analytical dimensions, including assessment paradigm, domain coverage, granularity, aggregation logic, and translation feasibility, highlighting the greater functional detail embedded in the SRI methodology. Drawing on measurement theory and multi-criteria decision analysis, this research demonstrates that the two frameworks operate in fundamentally different measurement spaces: the SRI uses ordinal functionality levels within a compensatory multi-criteria framework, whereas the BACS standard applies ratio-scale efficiency factors within a non-compensatory classification structure.
A translational mapping linking SRI Method B services to BACS standard control functions is developed to assess practical interoperability. Results show that 56% of SRI services map directly, 31% partially, and 13% have no equivalent representation, with major gaps in electricity management, dynamic envelope technologies, and EV charging. The SRI2MARKET pilot evidence indicates that even top-tier BACS Class A buildings achieved an average SRI score of approximately 43%, corresponding to SRI Class E, across 172 pilot assessments in seven EU Member States (Pascual & Boneta, 2024), as several non-energy SRI domains remain unaddressed.
These findings highlight structural incompatibility between the frameworks but demonstrate that procedural convergence can reduce double-assessment burdens during the 2026–2027 EPBD implementation period.
© 2026 Kriti Bhalla, Malabika Basu, Ciara Ahern, published by European Council for an Energy Efficient Economy (eceee)
This work is licensed under the Creative Commons Attribution 4.0 License.