Deep dive: Low-carbon buildings & retrofits — what's working, what's not, and what's next

Buildings across the European Union consume roughly 40% of total energy and generate 36% of energy-related CO2 emissions, yet the weighted average annual renovation rate sits at just 1% of the existing stock. The European Commission's 2025 progress report on the Renovation Wave strategy found that only 11% of renovations between 2020 and 2024 achieved "deep" energy performance improvements of 60% or greater, while the remaining 89% delivered marginal savings that will lock in suboptimal performance for decades (European Commission, 2025). For sustainability professionals navigating the EU's building decarbonization landscape, the gap between policy ambition and on-the-ground delivery defines both the core challenge and the largest commercial opportunity in climate action today.

Why It Matters

The EU's revised Energy Performance of Buildings Directive (EPBD), adopted in April 2024, mandates that all new buildings achieve zero-emission status by 2030 and that member states establish national renovation pathways targeting the worst-performing 15% of building stock by 2030 and 43% by 2033. These requirements create an estimated renovation market of EUR 275 billion per year through 2030, according to the Buildings Performance Institute Europe (BPIE, 2025). Failure to scale low-carbon building solutions will not only miss these regulatory targets but will also undermine the EU's broader 2030 and 2050 climate commitments, since buildings represent the single largest source of avoidable emissions after power generation.

The financial stakes are significant. The European Investment Bank estimated in 2025 that buildings with Energy Performance Certificate (EPC) ratings of F or G trade at a 15 to 25% discount compared to A-rated properties in major EU markets including Germany, France, and the Netherlands. This "brown discount" is accelerating as mortgage lenders increasingly factor energy performance into loan-to-value calculations, and the European Central Bank's climate stress testing now includes stranded asset risk from energy-inefficient commercial real estate portfolios (EIB, 2025).

Key Concepts

Deep retrofit refers to a comprehensive building renovation that reduces primary energy demand by at least 60%, typically involving envelope upgrades (insulation, windows, airtightness), mechanical system replacement (heat pumps, heat recovery ventilation), and renewable energy integration. Deep retrofits contrast with "shallow" or staged renovations that address individual components without achieving systemic performance improvement.

Embodied carbon accounts for the greenhouse gas emissions associated with manufacturing, transporting, and installing building materials and systems. As operational carbon declines through electrification and grid decarbonization, embodied carbon becomes a larger share of a building's whole-life carbon footprint, often representing 50% or more for new low-energy buildings.

Energiesprong is a Dutch-originated industrialized retrofit model that uses factory-manufactured facade panels, integrated rooftop energy systems, and standardized mechanical modules to deliver net-zero-energy retrofits in under two weeks of on-site installation. Performance is guaranteed through energy service contracts, and the retrofit cost is financed through the energy savings achieved.

Building Performance Standards (BPS) are regulatory frameworks that set mandatory energy or emissions intensity limits for existing buildings, with compliance deadlines that tighten over time. The EU's EPBD creates the framework for national BPS implementation, while cities like Amsterdam, Paris, and Copenhagen have adopted local versions with stricter timelines.

Passivhaus/Passive House is a voluntary performance standard requiring buildings to achieve space heating demand below 15 kWh per square meter per year, achieved through super-insulation, airtight construction, high-performance windows, and mechanical ventilation with heat recovery. Over 100,000 Passive House certified units have been completed across Europe as of 2025.

What's Working

Industrialized Retrofit at Scale

The Energiesprong model has moved from Dutch pilot to European deployment. As of early 2026, over 8,500 homes across the Netherlands, France, the United Kingdom, Germany, and Italy have received Energiesprong-style industrialized retrofits. In the Netherlands, housing associations Eigen Haard and Woonbron have completed portfolios of 500+ units each, with verified energy savings averaging 70 to 80% and tenant satisfaction rates above 85% (Energiesprong International, 2025). The factory-manufactured approach reduces on-site installation time to 5 to 10 working days per dwelling, compared with 8 to 16 weeks for conventional deep retrofits. Construction quality is more consistent because precision manufacturing eliminates the variability of on-site trades. In France, the Energie Sprong program supported by the government's France Relance recovery fund completed 2,100 social housing retrofits between 2022 and 2025, achieving average whole-building energy use reductions of 73%.

Heat Pump Deployment in Existing Buildings

EU heat pump sales reached 3.2 million units in 2025, up from 2.2 million in 2022, with the strongest growth in retrofit applications across France, Germany, Italy, and Poland. Air-source heat pumps have become the default replacement for gas boilers in many markets, with installed costs falling 12 to 18% between 2022 and 2025 as manufacturing capacity expanded. In Germany, the revised Buildings Energy Act (GEG) requires that heating systems installed from January 2024 onward use at least 65% renewable energy, effectively mandating heat pumps or district heating connections in most replacement scenarios.

Performance data from the Fraunhofer ISE large-scale monitoring program, covering over 4,000 heat pump installations in existing German buildings, shows median seasonal coefficients of performance (SCOP) of 3.1 for air-source units and 4.2 for ground-source units in buildings with radiator systems, confirming that heat pumps deliver efficient performance even without underfloor heating (Fraunhofer ISE, 2025). Crucially, the data shows that proper system sizing and hydraulic balancing matter more than building fabric quality for heat pump efficiency.

Whole-Life Carbon Assessment in New Construction

Whole-life carbon assessment (WLCA) has moved from voluntary best practice to regulatory requirement across several EU markets. France's RE2020 regulation, effective since January 2022, sets declining embodied carbon thresholds for new buildings, with the 2025 threshold requiring a 15% reduction from the 2022 baseline. Denmark introduced mandatory WLCA reporting for new buildings above 1,000 square meters in 2023, with a 12 kg CO2e per square meter per year limit (including both operational and embodied carbon). The Netherlands requires Environmental Performance of Buildings (MPG) scores below 0.8 for new residential buildings, effectively capping embodied carbon.

These regulations are driving measurable shifts in material specification. Cross-laminated timber (CLT) construction starts in the EU increased 34% between 2023 and 2025, and low-carbon concrete with 50% or greater clinker substitution now represents 18% of ready-mix deliveries in France and the Netherlands (GCCA, 2025).

What's Not Working

Renovation Rate Stagnation

Despite the Renovation Wave strategy's target of doubling the annual renovation rate to 2% by 2030 and tripling the deep renovation rate, actual progress has been negligible. Eurostat data shows that the weighted average renovation rate across EU-27 remained at 1.0 to 1.1% through 2025, essentially unchanged from 2019 levels. The deep renovation rate (renovations achieving >60% energy reduction) stands at approximately 0.2%, far below the 1.0% target needed to decarbonize the building stock by 2050 (BPIE, 2025).

The bottleneck is not technology but delivery infrastructure. The EU faces a shortage of approximately 1.5 million skilled construction workers needed for renovation, according to the European Construction Industry Federation (FIEC). Training pipelines for heat pump installers, insulation specialists, and airtightness testers remain undersized relative to demand. In Germany alone, the Federal Association of Heat Pump Manufacturers estimates that 60,000 additional certified installers are needed by 2028 to meet GEG compliance demand, against current training capacity of roughly 8,000 per year.

Split Incentive Problem in Rental Housing

Approximately 30% of EU households live in rented accommodation, and the split incentive problem, where landlords bear renovation costs but tenants capture energy savings, continues to block retrofit investment in this segment. While several member states have introduced mechanisms to partially address this barrier (France's "eco-pret" zero-interest loans, Germany's Modernisierungsumlage allowing landlords to pass 8% of renovation costs to tenants annually), none has fully resolved the economic misalignment. A 2025 study by the Wuppertal Institute found that rental housing renovation rates in Germany were 40% lower than owner-occupied housing renovation rates across equivalent building typologies and age cohorts.

Fragmented Policy Implementation

The EPBD grants member states significant flexibility in transposing its requirements into national law, leading to widely divergent implementation timelines, performance thresholds, and enforcement mechanisms. As of early 2026, only 9 of 27 member states had published their national building renovation plans as required under the directive, and the published plans vary dramatically in ambition and specificity. Minimum Energy Performance Standards (MEPS) implementation ranges from binding mandates in the Netherlands (EPC C requirement for offices from 2023) to aspirational targets without enforcement mechanisms in several Eastern European member states (European Commission, 2025).

Performance Gap Between Design and Operation

Monitored building performance data consistently shows that actual energy consumption exceeds design predictions by 20 to 40% in new low-energy buildings and 30 to 60% in deep retrofits. The ALDREN research project, covering 227 deep retrofit projects across 8 EU countries, found a median performance gap of 35%, attributable to construction defects (poor airtightness, thermal bridges), occupant behavior differences from design assumptions, and inadequate commissioning of mechanical systems (ALDREN, 2024). This performance gap undermines the financial returns that justify retrofit investments and erodes confidence among building owners and financiers.

Key Players

Established Companies

Saint-Gobain: global building materials manufacturer with EUR 47 billion in 2024 revenue, producing insulation, glazing, and interior products used in renovation projects across all EU markets. Knauf: German-headquartered insulation and drywall manufacturer operating 300 production sites worldwide, with a dedicated renovation solutions division targeting the EU deep retrofit market. Daikin Europe: the EU's largest heat pump manufacturer with a production capacity of over 1.5 million units annually across factories in Belgium, the Czech Republic, and Turkey. Viessmann Climate Solutions (Carrier Global): following the 2023 acquisition by Carrier, Viessmann's heat pump and climate technology portfolio serves the European retrofit market with integrated heating, cooling, and ventilation systems.

Startups and Innovators

Ecoworks: Berlin-based industrialized retrofit company delivering Energiesprong-style net-zero renovations for multi-family housing, with over 1,200 units completed. Renowatt: Spanish proptech platform that uses building energy modeling and AI to generate retrofit roadmaps and connect building owners with certified contractors. Hometree: UK-based home energy services company offering heat pump installation with performance-guaranteed service contracts. Q-Bot: London-based robotics company using autonomous underfloor insulation robots to install spray-applied insulation in occupied buildings without tenant disruption.

Investors and Funders

European Investment Bank: committed EUR 9 billion to building renovation financing between 2023 and 2025 through direct lending and intermediated credit lines. KfW: Germany's state development bank administering the Federal Support for Efficient Buildings (BEG) program, disbursing EUR 15 billion in renovation grants and subsidized loans in 2024. Climate-KIC (EIT): the EU's largest climate innovation initiative, funding building renovation technology development and market acceleration through its Built Environment program.

KPI Benchmarks

Metric	Current EU Average	Best Practice	2030 Target
Annual renovation rate	1.0-1.1%	2.5% (Netherlands)	2.0%
Deep renovation share	0.2% of stock/yr	0.8% (France social housing)	1.0%
Heat pump SCOP (air-source, retrofit)	2.8	3.5+	3.5
Embodied carbon, new residential	8-12 kg CO2e/m2/yr	5-6 kg CO2e/m2/yr	<8 kg CO2e/m2/yr
Design-to-operation performance gap	25-40%	<10%	<15%
Retrofit cost, deep (EUR/m2)	400-800	250-350 (industrialized)	<300
EPC improvement post-retrofit	1-2 classes	3+ classes	3+ classes

Action Checklist

• Audit your portfolio for EPBD compliance exposure by mapping all assets against 2030 and 2033 MEPS thresholds for worst-performing buildings
• Benchmark operational energy performance against design intent using 12 months of metered data and investigate any gap exceeding 20%
• Evaluate industrialized retrofit solutions (Energiesprong or equivalent) for repetitive building typologies in your portfolio to reduce per-unit cost and installation time
• Specify whole-life carbon assessments for all new construction and major renovation projects, including embodied carbon in material selection decisions
• Develop a heat pump deployment strategy that includes hydraulic balancing and emitter upgrades alongside unit installation to ensure optimal SCOP
• Secure workforce capacity by establishing framework agreements with certified retrofit contractors and investing in upskilling programs for existing maintenance teams
• Integrate building energy performance data into financial reporting and asset valuation models to quantify brown discount risk and green premium opportunity

FAQ

Q: Can heat pumps work effectively in older, poorly insulated European buildings? A: Yes, with proper system design. Fraunhofer ISE monitoring data from over 4,000 installations demonstrates that air-source heat pumps achieve seasonal coefficients of performance of 2.8 to 3.2 in pre-1980 buildings with conventional radiators. The key requirements are correct sizing (based on measured heat loss, not rules of thumb), hydraulic balancing of the distribution system, and, where necessary, selective radiator upgrades in the coldest rooms. Full envelope retrofit is beneficial but not a prerequisite for effective heat pump operation.

Q: What is the realistic cost premium for a Passive House or near-zero-energy new build compared to code-minimum construction? A: Current EU market data shows a cost premium of 5 to 12% for Passive House certification over minimum EPBD compliance, depending on building type, climate zone, and local labor costs. For multi-family residential buildings in central and northern Europe, the premium typically falls in the 6 to 8% range. This premium is declining as supply chains mature, and the higher upfront cost is offset by 70 to 80% lower heating energy costs over the building's life, with simple payback periods of 8 to 15 years at current energy prices.

Q: How should building owners prioritize between operational carbon reduction and embodied carbon reduction? A: For existing buildings, operational carbon reduction through retrofit and electrification should be the priority, since the embodied carbon of the existing structure is already "spent" and operational emissions will accumulate for decades. For new construction, both dimensions matter equally. Use whole-life carbon assessment to evaluate trade-offs: for example, additional insulation reduces operational carbon but adds embodied carbon, and the optimal thickness depends on the local grid carbon intensity, climate zone, and building lifespan.

Q: What financing mechanisms are most effective for scaling deep retrofits in social housing? A: The most successful models combine public grants covering 30 to 50% of capital cost with long-term, low-interest loans (15 to 25 years) serviced from verified energy savings. The Dutch Stroomversnelling model and France's Societes de Tiers-Financement provide templates. Energy performance contracts with guaranteed savings transfer performance risk from the building owner to the retrofit provider, making the investment bankable. The European Investment Bank's ELENA facility provides technical assistance grants for project development, covering the 3 to 5% of project cost required for energy audits, procurement, and contract structuring.

Sources

• European Commission. (2025). Progress Report on the Renovation Wave Strategy: 2024 Assessment. Brussels: Directorate-General for Energy.
• Buildings Performance Institute Europe. (2025). EU Building Renovation: Market Analysis and Outlook 2025-2030. Brussels: BPIE.
• European Investment Bank. (2025). Climate and Energy Lending: Building Renovation Portfolio Review. Luxembourg: EIB.
• Fraunhofer Institute for Solar Energy Systems. (2025). Heat Pump Field Monitoring: Performance Data from 4,000+ Installations in Existing Buildings. Freiburg: Fraunhofer ISE.
• Global Cement and Concrete Association. (2025). Low-Carbon Concrete Market Report: European Deployment Trends. London: GCCA.
• ALDREN Consortium. (2024). Closing the Performance Gap in Deep Energy Renovation: Findings from 227 Projects across 8 EU Countries. Brussels: European Commission Horizon 2020.
• Energiesprong International. (2025). Net-Zero Energy Retrofit Programme: 2024 Annual Report and Market Outlook. Gouda: Energiesprong Foundation.