4RinEU will define robust, cost-effective, tailorable deep renovation technology packages supported by usable methodologies, feeding into reliable business models. The project will minimize failures in design and implementation, manage different stages of the deep renovation process, from the preliminary audit up to the end-of-life, and provide information on energy, comfort, users’ impact, and investment performance.The 4RinEU deep renovation strategy is based on 3 pillars: (i) technology (driven by robustness) to decrease net primary energy use (60 to 70% compared to pre-renovation), allowing a reduction of life cycle costs over 30 years (15% compared to a typical renovation) (ii) methodology (driven by usability) to support the design and implementation of the technologies improving the information flow and knowledge sharing among stakeholders to sustain participative design, ensuring to halve the current renovation time (iii) business models (driven by reliability) to enhance the level of confidence of deep renovation investors, increasing the EU building stock transformation rate up to 3% by 2020. The 10 main results of 4RinEU will address the following objectives: Technology: to reduce demand (Prefab Multifunctional Façade, Comfort Ceiling Fan), to improve energy efficiency (Plug&Play Energy Hub, Objective-based RES Implementation), to improve building operations (Sensible Building Data Handler), and to reduce construction waste (Strategies for Components End-Of-Life). Methodology: to accurately understand renovation issues and potentials (Cost-Optimal Energy Audit), to ensure an effective and participated design (Investor and Building User-Oriented Design Tool and Method based on BIM), to reduce construction time and failures (Deep Renovation Implementation Management). Business model: to identify the level of risk of renovation process and to enable well-founded investments supported by tailor-made financial tools (Cost-effectiveness Rating System).