Introduction

The recast Energy Performance of Buildings Directive (EPBD) calls for building renovation to accelerate sharply if the EU is to reach a zero-emission building stock by 2050. Yet the way renovation has traditionally been financed — through non-repayable grants — is increasingly seen as insufficient to mobilise investment at the scale required. Evidence shows that heavy reliance on grants limits the leverage of private capital, raises questions about additionality, and can often channel support to those who need it least. Both the EPBD and the Energy Efficiency Directive (EED) now point towards a different model: one where public funds are used strategically — through loans, guarantees, blended finance and technical assistance — to de-risk investment and mobilise private capital, while grants remain targeted at vulnerable households and worst-performing buildings.

Translating this shift into practice is not straightforward. Municipalities, housing providers, ESCOs and project developers are often left navigating a fragmented and unfamiliar financing landscape, without a clear sense of which instruments are financially viable, institutionally feasible, or available at the right moment in a project's lifecycle.

The GreenRenoV8 project, an EU LIFE Clean Energy Transition initiative on cost-effective decarbonisation and seismic resilience of the building stock, set out to close this gap. The result is the Building Renovation Financing Toolkit — three complementary tools that help users answer three questions in turn: is a financing approach affordable, is it feasible in their context, and when can it realistically be applied?

Why grants alone will not get us there

For two decades, public support for building renovation in much of Europe has meant one thing: a grant. Grants are simple to communicate and popular with beneficiaries, but the evidence on their use at scale is sobering. Where major EU and national funds have been disbursed predominantly as non-repayable support, the result has too often been limited leverage of private capital, weak additionality — support flowing to households and companies that would have renovated anyway — and public budgets exhausted long before renovation targets are met.

EU policy has drawn the conclusion. The recast EPBD treats financing as a central enabler of a zero-emission building stock by 2050 and asks Member States to put in place stable, long-term financing strategies that use public money strategically: to address market failures, to de-risk investment and to mobilise private capital through financial instruments, while prioritising grants for vulnerable households and the worst-performing buildings. The Energy Efficiency Directive points the same way, promoting dedicated financing facilities that combine grants, financial instruments and technical assistance, and framing project aggregation and project development support as essential complements to any financial product. The Common Provisions Regulation for 2021–2027 has removed much of the legal uncertainty around combining grants and financial instruments within a single operation, so that a grant can now sit inside a loan as an interest-rate subsidy, a capital rebate or technical assistance. The European Affordable Housing Plan of December 2025 and the proposal for the 2028–2034 Multiannual Financial Framework confirm the direction of travel: fewer stand-alone subsidies, more blended finance, revolving funds and guarantees.

Two concepts underpin this shift. Concessionality is the mechanism — financing on better-than-market terms, whether a lower rate, a longer tenor, a guarantee or a grant component. Additionality is the outcome — the renovation that would not have happened without it.  Public money should aim to achieve as much of the latter with as little of the former as possible.

Three questions, not one

Policy direction is one thing; a municipality, a housing association, an ESCO, or a building owner faced with a concrete project is another. GreenRenoV8 set out to build a decision-support framework that could bridge the two.

The initial ambition was a single, integrated tool. Iterative development with project partners showed why that could not work. A financial model can tell you which financing structure is cheapest, but it cannot tell you whether a municipality is legally able to enter an energy performance contract, whether a homeowners’ association can reach the majority needed to take on a collective loan, or whether the technical assistance grant that would have paid for the energy audit is still open by the time the project reaches the design stage. Financial attractiveness alone is not sufficient for a decision. Feasibility — eligibility, institutional capacity, procedural constraints — and timing matter just as much.

The framework therefore evolved into a layered system in which each layer answers one question:

• Which financing approaches can this entity realistically use? (feasibility)
• When in the project lifecycle does each instrument come into play? (timing)
• Which of the feasible options is financially viable and affordable? (affordability)

The three tools that answer these questions together form the Building Renovation Financing Toolkit, accessible free of charge through a single-entry page on the GreenRenoV8 website (Figure 1).

_{Entry page of the Building Renovation Financing Toolkit: three questions, three tools. Source: GreenRenoV8.}

Tool 1: the Financing Navigator

The Financing Navigator is a guided decision tree. The user chooses a building category — single-family house, multi-apartment building, commercial building, or public building — and answers a short series of questions with ‘yes’, ‘maybe’, or ‘no’. The questions deliberately avoid asking for market or regulatory expertise. Instead, they probe the conditions that in practice decide whether a financing route is open: willingness to take on debt and repayment obligations; ability to meet eligibility and performance requirements; readiness to prepare technical and administrative documentation and to undergo procedures such as energy audits; organisational and governance capacity, including the ability to coordinate collective decisions in multi-owner buildings; appetite for long-term contracts; and willingness to delegate implementation and performance risk to an external actor such as an ESCO.

The decision logic runs on two levels. Building-specific pathways capture the governance and implementation realities of each building type; mechanism-specific pathways then apply the requirements of each financing route — grants and subsidies, loans including green lending products, guarantees, on-bill financing, fiscal instruments, energy performance contracting and public–private partnerships. Unsuitable options are eliminated progressively, and each question carries a short explanation of why the answer matters.

The output is not a single best instrument. It is a personalised shortlist of financing pathways compatible with the user’s project and organisation. The Navigator does not check whether a given product exists in the user’s country. It checks whether the project and the entity behind it are ready to use it. The distinction is deliberate: it keeps the tool valid across the very different financing markets of the pilot regions, and it points users towards the questions they need to take to their bank, their energy agency or their national one-stop shop.

Tool 2: the Financing Timeline

Analysis of renovation processes across the pilot regions revealed a gap that neither a financial model nor a decision tree can fill: financing instruments are not equally available at every stage of a project. Technical assistance facilities such as ELENA finance feasibility studies and procurement support, but only if approached before that work is commissioned; lenders applying EU Taxonomy criteria need to be engaged while the design can still be adjusted; fiscal incentives and capital rebates materialise only after completion and verification. A financing strategy that ignores this sequencing leaves money on the table.

The Financing Timeline is an interactive Gantt-style view mapping each financing mechanism across the seven phases of a renovation project, from strategic preparation through to long-term operation and repayment, with drill-down into what happens in each phase. It performs no calculations and filters nothing; its value lies in showing which instruments are open at the user’s current stage, which opportunities have already closed, and which preparatory steps unlock the options ahead. In the language of the framework, it operationalises delivery readiness.

Tool 3: the Financial Feasibility Toolbox

The quantitative layer of the toolkit did not start from scratch. A review of existing decision-support tools — among them the Triple-A standardised toolbox, the eCentral decision tree and the UN ESCWA toolkit for energy efficiency financing — showed that sound financial and economic appraisal methods for renovation already existed, but that none combined instrument comparison, blended finance and integrated energy-plus-seismic renovation in a form practitioners could readily use. The MESTRI-CE Financial and Economic Evaluation Toolbox, an Excel-based cost–benefit model built on the EU Cohesion Policy 2021–2027 appraisal methodology and adapted to buildings, was selected as the foundation and upgraded in two directions.

First, the range of financing structures was extended from nine to twelve, adding own funds combined with fiscal instruments, green mortgages combined with grants and own funds, and on-bill financing combined with own funds and grants — the blended structures the policy framework now favours. Financing sources are classified dynamically as public, private, or EU contribution, and a redesigned dashboard compares financing structure, financial net present value and payback across all twelve options side by side.

Second, the socio-economic module was extended to value seismic resilience: users enter expected annual economic loss and expected annual fatalities before and after renovation, and the toolbox monetises the avoided losses — using a value of statistical life based on EU reference values — alongside CO₂ and energy benefits in the economic net present value, economic rate of return, and benefit–cost ratio.

A new one-page summary sheet brings the results together — project data, recommended financing approaches, financial and socio-economic indicators, and energy performance improvement — in a format designed to feed directly into a building renovation passport.

A worked example: a heritage-protected school in Ljubljana

Vodmat Primary School in Ljubljana shows what the toolkit adds on a real building. Built in 1965 and protected as cultural heritage, the 4,678 m² reinforced-concrete complex combined poor energy performance with inadequate seismic and fire safety. The Municipality of Ljubljana renovated it in 2019 within its second energy rehabilitation programme for public buildings: EUR 1.25 million of energy measures and EUR 0.65 million of seismic strengthening, plus fire-safety, radon, electrical and interior works that brought the total to about EUR 3.6 million excluding VAT (Figure 2). The energy measures were financed 40% by a national and EU cohesion grant and 60 % by an ESCO consortium (Petrol, Resalta and Javna razsvetljava) repaid from guaranteed energy-cost savings; the rest came from the municipal budget. Measured results: heating demand −61%, delivered energy −47%, operational emissions −97 tCO₂ a year, and some 2,165 m² of walls strengthened.

_{Vodmat Primary School, Ljubljana, after the combined energy and seismic renovation. Source: GreenRenoV8 case study collection.}

Run through the Navigator, a public owner willing to delegate implementation and performance risk, able to commit to a long-term contract and to run a public procurement, is steered towards energy performance contracting, grants and own funds, and away from instruments built for households, such as green mortgages or on-bill financing. The Timeline adds the sequencing: the grant window has to be secured before the ESCO tender, heritage approvals before the design is frozen, and the contract only starts paying for itself once monitored savings are verified.

The Toolbox is where the added value becomes quantitative. We entered the energy and seismic package (EUR 1.9 million) as if it were being appraised today: a 20-year reference period, 4% financial and 3% social discount rate, constant prices excluding VAT, district-heat and electricity savings of about EUR 28,000 a year plus EUR 10,000 a year in lower maintenance, and 97 tCO₂ a year avoided. Three results stand out (Figure 3).

_{Vodmat Primary School in the Financial Feasibility Toolbox — (a) total cost to the municipality of twelve financing structures for the same package; (b) economic net present value with and without avoided seismic losses. Source: authors, GreenRenoV8 Financial Feasibility Toolbox.}

First, the financial return on the investment itself is negative (FNPV(C) of about −EUR 1.2 million): energy savings alone do not repay a deep renovation of a 1960s school, which is precisely why the financing structure matters. Second, the tool’s comparison of twelve structures ranks the combination actually used — EnPC with a grant and own funds — as the cheapest for the municipality, at about EUR 1.19 million over twenty years against EUR 1.42 million for grant plus own funds, EUR 1.8–2.4 million for the loan-based options and over EUR 2.6 million for bonds, because the ESCO carries part of the capital and is paid from savings rather than from the budget. Third, the seismic module changes the societal verdict. With energy and CO₂ benefits only, the economic net present value of the package is slightly negative (−EUR 0.18 million).

The toolkit does not produce a different decision for Vodmat. It makes the reasoning explicit, shows what the municipality’s choice saved, and puts a number on the resilience benefit that is otherwise left out of the business case — information that can also be used for the next school, including in a municipality without an ESCO market of its own.

One entry point, tested on real projects

The three tools are deliberately different in nature — two browser-based applications and one spreadsheet model — but are presented as one suite through a lightweight web front end connected to the project website. A user can start with the Navigator, take the shortlist to the Timeline to see when each option applies, and run the survivors through the Toolbox to compare cost and return. Or use any of the three on its own.

Testing is now under way on real renovation cases in Austria, Flanders, Italy, Greece and Slovenia, chosen to span building types, ownership structures and national financing contexts. Feedback from these pilots — on decision rules, on usability, on where the questions fail to capture local reality — will be built into the next release. Planned enhancements include links to educational resources on each mechanism, connections to regularly updated external databases of national financing offers such as the one developed by the Renoverty project, and additional performance indicators.

None of this is financial advice, and none of it replaces legal, technical or financial due diligence. The Toolbox assumes the options modelled are available; the Navigator assesses readiness, not local availability. The outputs are a structured, transparent starting point that lets stakeholders from very different backgrounds frame their financing challenge, ask the right questions and engage more effectively with the specialists who will close the deal.

Conclusions

Meeting the EPBD’s renovation ambition requires moving decisively beyond grants alone, towards financing that combines public and private resources and is matched to the project, the entity and the moment. 

GreenRenoV8’s Building Renovation Financing Toolkit turns that policy principle into three practical questions — is it feasible, when does it apply, and is it affordable? — and gives building professionals free tools to answer each. Now being tested across five pilot regions, the toolkit will be refined through 2027. The tools are available via the GreenRenoV8 website, and feedback from users across Europe is welcome.