The True Cost and Roadmap for Making European Homes Smart-Ready

By Antonia Egli and Radhika Deorukhkar (Dublin City University) and edited by Vasilis Apostolopoulos, Paraskevi Giourka, Georgios Martinopoulos, Komninos Angelakoglou, Konstantinos Kourtzanidis, and Nikolaos Nikolopoulos

As Europe pushes towards climate neutrality and more energy-efficient housing, understanding how to transition our existing homes is crucial. The study “Smart readiness indicator evaluation and cost estimation of smart retrofitting scenarios – A comparative case-study in European residential buildings” dives deep into this transformation, exploring the technical and economic roadmap for upgrading typical European residential properties into truly intelligent, smart-ready buildings, driving the vision for Smart Buildings Europe.

What Did This Smart Building Study Investigate Across the EU?

This RINNO study, conducted by the Centre for Research and Technology Hellas (CERTH/CPERI), focuses precisely on applying the Smart Readiness Indicator (SRI) methodology. The research examines two common residential typologies, Single-Family Houses (SFH) and Multi-Family Houses (MFH) across five different EU Member States.

The core objective was twofold: to estimate the financial investment required for smart retrofitting and to quantify the resulting increase in the building’s SRI score under various upgrade plans. The researchers adopted a detailed, three-step assessment process, moving from a low-tech baseline to a fully integrated energy-and-smart-solutions upgrade. This systematic approach provides policymakers and homeowners with a much-needed cost-benefit analysis of the smart building revolution across Smart Buildings Europe.

What are the Core Findings on Smart Retrofitting Costs and SRI Scores?

The comparison between different retrofitting strategies yielded several important insights for the future of European housing:

• The Baseline Reality: The study first established the initial Smart Readiness Indicator (SRI) score for the baseline scenario. This score represents the national minimum requirements for buildings set by the European Energy Performance of Buildings Directive (EPBD). The low scores here highlight the significant gap between current mandatory standards and ambitious smart readiness goals.
• NZEB is a Critical Step: The second scenario modelled retrofitting with commercially available technologies specifically aimed at achieving Nearly Zero Energy Building (NZEB) status. This phase is crucial; it demonstrates how existing, market-ready solutions can dramatically boost energy efficiency and lay the foundational technical groundwork for true smartification.
• The Integrated Approach: The most comprehensive scenario involved an integrated retrofitting plan, which goes beyond Nearly Zero Energy Building (NZEB) standards to achieve a high degree of smart readiness that supports progress toward energy positiveness, and enables the building to function as an active node in the grid. This integrated approach is complex but reveals the full potential for optimal building performance and occupant control, suggesting that maximum benefit requires a holistic, combined upgrade.
• Smartification Comes with a Price Tag: By meticulously evaluating the cost associated with each stage from baseline to Nearly Zero Energy Building (NZEB), and then to the fully integrated smart upgrade toward Positive Energy Building (PEB), the research illustrates the cost effectiveness of SRI improvements, i.e. the investment required to enhance a building’s smart-readiness level. This economic analysis is essential for planning national subsidy schemes and for advising homeowners and housing associations on the necessary financial investment.

Why Do Smart Building Findings Matter for EU Policy and Homeowners?

The findings hold immediate relevance for anyone involved in Europe’s massive building renovation wave, aligning with the New European Bauhaus vision and demonstrating how smart-ready solutions, reflected by the Smart Readiness Indicator (SRI), can drive high-quality, people-centred building upgrades. Since buildings account for a large portion of energy consumption, their smartification is central to achieving the goals of the European Climate Law (Regulation EU 2021/1119), which targets climate neutrality by 2050.

For policy and finance, the cost estimations derived from studying two typical housing types across five nations offer a solid benchmark. This data can inform the design of targeted subsidies that make smart-ready buildings affordable for all citizens, moving the focus beyond just reducing energy use to also enhancing occupant well-being and flexibility.

In the construction industry, the scenarios provide a clear roadmap for retrofitting when combined with tailored passive building-envelope measures. Instead of disjointed upgrades, contractors can follow a systematic, phased approach: NZEB-first, then fully smart and energy upgrade toward PEB. For instance, in a multi-family house (MFH), the study shows how coordinated smart meter installation followed by a cloud-connected, dynamic heating, ventilation, and air conditioning (HVAC) system (integrated) offers the best return on investment for both energy savings and the final Smart Readiness Indicator (SRI) score. This approach ensures that retrofitting efforts are future-proofed and align directly with EU energy and climate goals.

How Can Europe Ensure Its Existing Homes Become Intelligent Spaces?

The transition to climate-neutral cities depends heavily on making our existing housing stock smarter. Realising the goals for Smart Buildings Europe is central to this effort. This research provides the essential blueprint, moving the discussion from if buildings should be smart to how much it will cost and the tangible benefits of each step. By adopting the principles of the Smart Readiness Indicator (SRI) and following an integrated retrofitting approach, we can ensure Europe’s homes are not only energy efficient but truly intelligent spaces for the next generation.

Reference:

Apostolopoulos, V., Giourka, P., Martinopoulos, G., Angelakoglou, K., Kourtzanidis, K. and Nikolopoulos, N. (2022) ‘Smart readiness indicator evaluation and cost estimation of smart retrofitting scenarios – a comparative case-study in European residential buildings’, Sustainable Cities and Society, 82, 103907. https://doi.org/10.1016/j.scs.2022.103921