Introduction

The Horizon 2020 iBRoad2EPC project represents a strategic initiative to advance the decarbonisation of the European building stock by bridging the gap between existing Energy Performance Certificates (EPCs) and the building renovation passport concept. Building on the results of the preceding Horizon 2020 iBRoad project, which focused on single-family homes, iBRoad2EPC expanded the scope to include multi-family and public buildings, as well as aspects beyond energy performance, to improve the reliability, usefulness, and effectiveness of EPCs. The project's approach and achievements are directly relevant to the Energy Performance of Buildings Directive (EPBD) following its 2024 recast, in particular Article 12, which mandates the introduction of renovation passport schemes.

Strategic approach and concept

The overarching strategy of iBRoad2EPC was to integrate renovation passport elements into national EPC schemes, rather than creating a competing stand-alone tool and process. This approach addressed the current limitations of EPCs, which often fail to trigger deep renovation or facilitate long-term planning. iBRoad2EPC positioned itself as a flexible option between the snapshot assessment provided by an EPC and the comprehensive, long-term planning offered by an individually tailored renovation passport. By combining these instruments, the project aimed to provide building owners with a customised roadmap for deep renovation, structured as a sequence of steps to avoid ‘lock-in’ effects, where early shallow renovations prevent future energy efficiency gains.

The project adopted a semi-flexible, modular approach, designed to adapt to the varying market maturity and legal frameworks of different EU Member States. The core of this system is the Basic Module, which constitutes the indispensable basis for implementation. This module requires an on-site visit by a trained expert and provides the essential technical information for a staged renovation roadmap, the core of the renovation passport, including descriptions of measures, their optimal timing and technical specifications derived from national climate targets.
 

_{Figure 1. Modular concept of iBRoad2EPC. The Basic Module can be enhanced with additional modules to adapt iBRoad2EPC to the requirements of implementing countries. 
Source: Training toolkit – Handbook for issuers – Guidance on how to create an iBRoad2EPC.}

Member States can then choose to expand this core function with additional modules based on their specific needs and data availability. The project developed or integrated several such modules:

• Energy Demand Module. Adds a dedicated display of energy consumption, energy efficiency class, greenhouse gas emissions and energy costs for each renovation step.
• Investment Cost Module. Estimates total investment, maintenance costs and energy-related additional costs to support financial decision-making.
• Indoor Environmental Quality (IEQ) Module. Based on the calculation tool developed under the Horizon 2020 X-tendo project, this module assesses health and comfort aspects, which are key co-benefits of renovation, using methodologies such as the Comfort Asset Rating Procedure (CARP).
• Smart Readiness Indicator (SRI) Module. Based on the SRI calculation tool provided by the European Commission, this module rates a building's capacity to adapt to occupant needs and the grid, aligning with the EPBD emphasis on smart technologies.
• Measured Energy Performance Indicator (MEPI) Module. Also developed under X-tendo, this module uses real consumption data to bridge the gap between calculated and actual performance.

Technical implementation: the iBRoad2EPC Assistant

To operationalise its approach, the project developed the iBRoad2EPC Assistant, an online back-end tool for energy experts. This software facilitates the creation of the renovation passport by guiding the issuer through the data entry process and generating a standardised output.
 

_{Figure 2. User interface in the iBRoad2EPC Assistant for describing the current building state. 
Source: Specification for the iBRoad2EPC software tools: Report on adaptation requirements for roll-out countries.}

A key advantage of the Assistant is its ability to reduce the burden on energy auditors through automation and pre-filled data. The tool utilises country-specific databases that contain renovation measures, technical specifications (e.g., U-values), and texts aligned with national Long-Term Renovation Strategies (LTRSs). When an auditor selects a measure, the Assistant automatically populates technical details and adds specific notes on how to prepare for subsequent renovation steps to ensure seamless integration. All notes are editable by the auditor.
 

_{Figure 3. User interface in the iBRoad2EPC Assistant to create and specify renovation measures. 
Source: Specification for the iBRoad2EPC software tools: Report on adaptation requirements for roll-out countries.}

The Assistant is designed for interoperability. It allows for the import of EPC data from Extensible Markup Language (XML) or Excel files and features an Application Programming Interface (API) to exchange data with third-party software, such as national EPC calculation tools, Digital Building Logbooks, or one-stop shops. This connectivity ensures that iBRoad2EPC can be embedded into the existing digital ecosystem of Member States, avoiding double data entry and ensuring consistency. The output is a digital document that can be updated over time, accessible via a QR code attached to the standard EPC.
 

_{Figure 4. Overview page of the iBRoad2EPC online output form. 
Source: Specification for the iBRoad2EPC software tools: Report on adaptation requirements for roll-out countries.}

National adaptation and pilot implementation

A major achievement of the project was the successful adaptation of the iBRoad2EPC model to the specific contexts of six pilot countries: Bulgaria, Greece, Poland, Portugal, Romania and Spain. The project engaged National Advisory Committees (NACs) in each country to define the optimal integration strategy.

• Bulgaria: The market is characterised by low trust in EPCs and a lack of mechanisms for staged renovation. iBRoad2EPC was adapted to provide ready-made recommendations aligned with climate targets, simplifying the complex national audit procedure.
• Greece: With EPCs viewed primarily as a bureaucratic necessity, the project positioned iBRoad2EPC as an added-value tool to support national subsidy schemes such as ‘Exikonomo’. Technical integration with the ‘Buildingcert’ EPC platform was explored to automate data retrieval.
• Poland: Facing low public trust and no official calculation software, the strategy focused on promoting iBRoad2EPC as a voluntary tool to support thermal modernisation programmes, potentially linking it to grant schemes.
• Portugal: Building on an advanced EPC system and the ‘casA+’ One-Stop Shop, iBRoad2EPC was adapted to integrate with existing platforms via XML, positioning it as a unifying tool for various energy efficiency instruments.
• Romania: With a Digital Building Registry under development, the project aligned iBRoad2EPC to serve as a pathway toward a national Renovation Passport, focusing on energy demand and connecting with future digital infrastructures.
• Spain: To address the low perceived value of existing EPCs, iBRoad2EPC was positioned to provide high-value, long-term guidance, aligning with the ‘Libro del Edificio Existente’ (existing building book) and leveraging XML integration to automate data.
   

_{Figure 5. An additional page with a QR code and an internet link is added to the EPC. These will direct the building owner to their iBRoad2EPC document online. 
Source: iBRoad2EPC in depth: Technical report on the definition of the proposed concept, content and methodology.}

Capacity building and training

Recognising that the quality of renovation advice depends heavily on the skills of the experts, iBRoad2EPC developed comprehensive training toolkits. These materials targeted two main groups: energy auditors (EPC issuers) and construction professionals.

The training for energy auditors focused on the methodology of staged deep renovation, the use of the iBRoad2EPC Assistant, and the integration of new indicators like SRI and IEQ. A total of 202 energy experts were trained across the six pilot countries. The training emphasised the mandatory on-site visit, a core quality assurance feature of the iBRoad2EPC approach, ensuring that recommendations are tailored to the specific building context.
 

_{Figure 6. Five steps to issue the iBRoad2EPC. Source: Training toolkit: Training Presentation.}

Furthermore, the project produced training modules for construction professionals to ensure they can interpret and implement the measures prescribed in the renovation passports, thereby bridging the gap between planning and execution. An advisory package was also created for public authorities to support them in designing and implementing Renovation Passport schemes.

Field testing and stakeholder feedback

The viability of the iBRoad2EPC approach was validated through extensive field testing. 48 trained energy experts tested the tool on 57 buildings (30 residential and 27 public/administrative) across the pilot countries. The results provided strong evidence of the tool's effectiveness and market acceptance, including:

• User acceptance: 85% of energy experts and 70% of building owners rated the information provided by iBRoad2EPC as very or extremely useful.
• Strategic value: 87% of experts and 78% of owners confirmed that the tool successfully provided an outline of a long-term renovation plan.
• Lock-in avoidance: The feature describing preparatory measures to avoid lock-in effects was the highest-rated component, with 83% of experts rating it as very or extremely useful.
• Motivation: 63% of experts believed the tool would motivate owners to renovate, and more than half of the building owners felt motivated to implement concrete measures.
• Recommendation: 91% of experts stated they would recommend the tool to clients, and 80% of building owners would recommend it to others.

Stakeholders generally favoured a voluntary introduction of iBRoad2EPC as a complement to the EPC, although opinions varied slightly by country regarding mandatory usage for specific building types. The feedback underscored the importance of the on-site visit, which owners found highly valuable despite the extra effort required from experts.
 

_{Figure 7. Free text feedback from energy experts on what they liked about the iBRoad2EPC Assistant. Source: iBRoad2EPC field test results.}

Policy integration and EU roadmap

A significant achievement of the project is the alignment of iBRoad2EPC with the evolving EU policy landscape, particularly the EPBD, even though the tools were developed before the 2024 recast. iBRoad2EPC already meets 11 out of 14 mandatory requirements and 7 out of 15 optional requirements for renovation passports set out in Annex VIII of the EPBD. Thanks to its modular structure, iBRoad2EPC can easily be expanded to meet all requirements. It thus supports Article 12 by providing a ready-to-use model for Member States to establish their Renovation Passport schemes by May 2026.

The project developed an EU Roadmap to guide policymakers in maximising the uptake of iBRoad2EPC. This roadmap outlines a three-step approach:

1. Baseline assessment: Mapping stakeholders and reviewing transposition timelines for the EPBD, Energy Efficiency Directive (EED), and Renewable Energy Directive (RED).
2. Setting the scene: Identifying national priorities and enablers, such as linking iBRoad2EPC to financial incentives or determining its mandatory/voluntary status.
3. Action plan: Developing specific actions for rollout, capacity building, financing, and monitoring.
    

_{Figure 8. Roadmap to implement iBRoad2EPC to accelerate deep renovation in the EU. 
Source: Accelerating deep renovation in the EU with renovation passports: EU roadmap proposing concrete measures to maximise the uptake of iBRoad2EPC schemes.}

For the six pilot countries, individual national guides were developed in close collaboration with the respective National Advisory Committees (NACs), including an overview of the current situation regarding EPCs and renovation passports, the proposed national iBRoad2EPC vision, and a national action plan on addressing legal, social, financial, and other parameters, along with the necessary steps, roles, and actions for the successful implementation of the national roll-out.

The project highlighted the critical role of financial incentives in the adoption of renovation passports. The iBRoad2EPC concept allows for incentives to be tied to specific, measurable improvements defined in the roadmap. Recommendations include using iBRoad2EPC to verify eligibility for green loans, reducing audit costs for owners through subsidies, and prioritising funding for measures that align with the long-term decarbonisation strategy.

Suitability for diverse building types

While the predecessor iBRoad project focused on single-family houses, iBRoad2EPC successfully expanded its scope to multi-family and public buildings. The project addressed specific challenges for these typologies:

• Multi-family buildings: The tool accommodates complex ownership structures and provides recommendations for both individual apartments and the building as a whole, focusing on measures that can be implemented during tenant changes or general maintenance.
• Public buildings: The tool supports public authorities in meeting the EED obligation to renovate 3% of public building floor area annually by prioritising buildings and defining renovation packages. The field tests confirmed that iBRoad2EPC is highly suitable for these building types, providing essential insights for long-term planning.

Conclusions

The iBRoad2EPC project has successfully delivered a validated, flexible and operational model for the building renovation passport, compatible with the EPBD’s provisions. By technically integrating renovation passport elements into the EPC ecosystem, developing a user-friendly software assistant, and demonstrating value through field tests in diverse national contexts, the project has created a practical pathway for Member States to accelerate deep renovation. Its achievements lie in the methodology and software developed, as well as the comprehensive framework of training, policy roadmaps, and stakeholder engagement that ensures the tool can be effectively deployed to support the EU's 2050 climate neutrality goals. Authorities interested in making use of the iBRoad2EPC results can obtain further information via the project website at www.ibroad2epc.eu.