Deep Renovations Offer a Fast Track to Cleaner European Cities

by Antonia Egli and Radhika Deorukhkar (Dublin City University), edited by Ginna Alexandra Castillo Mendigaña and Victor Fernandez

Europe’s Buildings Are the Climate Bottleneck, Deep Renovation Is the Fix

The race to cut carbon emissions across Europe relies heavily on transforming our aging building stock. Many older homes and commercial properties are energy drains, but finding the most effective and affordable solution for deep renovation remains a challenge. The Replicability Analysis Report, which is a part of the EU-funded RINNO project, addresses this head-on. By analysing the potential of advanced, bio-based renovation technologies, we explored how easily these solutions could be scaled up across Europe. The results provide clear evidence for policymakers looking to accelerate the green transition.

Inside the Replicability Analysis

The study is aimed to evaluate the replication potential of the RINNO technologies. The focus of the analysis was on four distinct urban and suburban areas across Europe: Lille (France), Slagelse (Denmark), Moschato-Tavros (Greece), and Jablonna (Poland). This diverse geographical scope ensured the findings were grounded in different local contexts and building typologies.

The core research question was whether replicating these solutions in similar, inefficient buildings in these regions could meet ambitious project goals for energy and emissions savings. We developed a Geographical Information Systems (GIS)-enabled tool to identify comparable buildings and estimate their potential impact. This led to the identification of 9,620 replicable buildings. The results were then tested against two scenarios, Conservative (CS) and Optimistic (OS), to establish a spectrum of likely outcomes.

Deep Renovation at Scale: Key Results

The analysis demonstrates that the scale-up of these deep renovation technologies has a highly positive potential across Europe, significantly exceeding the project’s targets for both energy and emissions reductions.

• Savings Exceed Conservative Targets by Over 85%

Even under the most modest Conservative Scenario (CS), where only the least effective technology was applied, the potential for Primary Energy Savings (PES) reached 285 GWh/year. This figure surpasses the project’s PES target of 157.6 GWh/year by 85%. The potential reduction in Greenhouse Gas (GHG) emissions under the CS was also substantial, reaching 106,735 tCO₂e/year against a target of 39,206 tCO₂e/year.

• High Energy and GHG Savings in the Best Case

In the Optimistic Scenario (OS) where a full renovation package is applied the total potential PES soared to 935.9 GWh/year. Similarly, GHG emission reductions reached 244,828 tCO₂e/year. This confirms the enormous impact a complete technological overhaul can have on Europe’s older building stock.

• Regional Differences in Performance

While the overall results are strong, performance varies significantly by region. Under the CS, individual building savings ranged from a low of 1% in Slagelse, Denmark, to a high of 35% in Jablonna, Poland. In contrast, under the OS, all regions showed excellent results, with savings ranging from 28% in Lille, France, to 71% in Slagelse, Denmark.

• Poland’s Outsized Contribution to GHG Reduction

The analysis revealed that the Jablonna region in Poland contributed 83% of the total GHG reduction under the Conservative Scenario. This exceptional result is largely attributed to a combination of a high building stock suitable for replication and the local electricity emission factor.

A Practical Roadmap for Cities and Policymakers

These findings have direct and actionable consequences for European policy and industry investment, providing an evidence-based foundation for decision-makers. The EU’s Energy Performance of Buildings Directive (EPBD) sets a target for residential building stock to reduce primary energy use by at least 16% by 2030.

The research provides a critical benchmark against this European Union goal. Our results show that under the ambitious Optimistic Scenario, all four demonstration regions would easily surpass the 16% reduction target. Even under the more realistic Conservative Scenario, the Greek (17% savings) and Polish (35% savings) regions already exceed this mandatory EU benchmark.

The methodology, which uses Geographical Information Systems (GIS), is a key takeaway for local authorities. By identifying and mapping the 9,620 replicable buildings at a city scale, the analysis offers an invaluable tool for urban planning. Decision-makers can now use this data to accurately prioritise intervention candidates. For instance, by comparing energy savings per square metre with the scale of the required investment, cities like Lille or Slagelse which showed lower CS savings can direct significant additional effort into intervening with more buildings or implementing broader technological solutions to meet the 16% target. This approach moves beyond theoretical metrics to provide a practical roadmap for financing and implementing renovations across Europe.

The Next Move: Scaling Deep Renovation Across Europe

The comprehensive replicability analysis confirms the strong potential of advanced renovation technologies to drive large-scale, deep energy transformation across the European building stock. The outcomes, which are expected to fall somewhere between the lower Conservative and upper Optimistic scenarios, offer a clear, positive spectrum for future impact. By combining technical innovation with granular geographical data, this research provides the actionable insights needed to significantly scale up energy-efficient renovation strategies.

Reference:
CIRCE (2025). An augmented intelligence-enabled stimulating framework for deep energy renovation delivering occupant-centred innovations. RINNO Project (GA 892071).