A Hub for Circularity (H4C) is a regional socio-technical ecosystem that enables large-scale industrial symbiosis, industrial–urban symbiosis (IUS), and circular economy solutions by closing energy, resource, and data loops at the territorial level. In practical terms, it is the coordinating platform that connects the actors who generate recoverable resources with those who can use them as industrial feedstock, so that materials which would otherwise reach landfill are kept in productive use.
What distinguishes an H4C from a one-off circular project is its role as an enabling structure rather than a single technology. It brings together governance, stakeholder collaboration, and data-driven decision support to organise dispersed waste streams, technologies, and partners into integrated, investable value chains.
The Hubs for Circularity concept has been recognised as a key element in the European Union’s strategy to advance the circular economy, aligning with the European Green Deal, the Circular Economy Action Plan, and Horizon Europe’s goals for climate neutrality and competitive sustainability. H4Cs are instrumental in accelerating the deployment of scalable and replicable circular economy solutions across European territories. An H4C focused on IUS creates synergies between industrial processes and urban services, such as energy, water, waste, mobility, and land use, to develop joint solutions that close resource loops at a territorial level, reduce environmental burdens, and enhance the efficiency and resilience of entire systems.
H4Cs provide a structured platform for implementing circular-economy solutions, ensuring that industries and urban areas maximise resource efficiency and minimise environmental impact. An Industrial-Urban H4C should follow a structured approach based on three fundamental elements:
For detailed information regarding the fundamental elements, please see section 2.2 of Deliverable D2.2.
Vision and Mission
General Vision: The vision of an H4C within the framework of Industrial Urban Symbiosis (IUS) is an interconnected system in which resources are used efficiently, waste is minimised, and resilient, sustainable environments are created. This vision is rooted in the belief that the future of industrial activity must align with the ecological boundaries of our planet, driven by innovation, cross-sector collaboration, and systemic resource optimisation (Deliverable 2.2).
Specific Vision: Each H4C should develop and continuously adapt a specific vision tailored to its regional context, responding to local needs and opportunities.
Mission: The mission of a H4C is to define and pursue clear medium- and long-term goals that contribute to systemic circularity and address regional challenges and opportunities. In the medium term, the H4C should define a set of circularity implementations that demonstrate the benefits of industrial-urban collaboration. In the long term, H4C envisions a just and regenerative transformation of European regions, where industrial, urban, and community systems work in symbiosis to foster circular and climate-neutral societies. Rooted in place-based action, H4Cs serve as inclusive innovation ecosystems that not only close loops of material, water, and energy flows, but also provide economic benefits and cultivate trust and shared purpose across sectors and communities.
More information about medium-term goals and long-term mission can be found in section 3.2 of Deliverable D2.2.
The fundamental principles and values of a H4C are:
A detailed explanation with regards to the fundamental principles and values of a H4C is provided in section 3.2 of Deliverable D2.2.
H4Cs progress through five conceptual stages, ranging from early awareness and networking to advanced systems with fully integrated symbiotic exchanges of energy, materials, and services. These stages provide a roadmap for transformation, applicable across diverse territorial and industrial contexts, and are measured against the Symbiosis Readiness Level (SRL) framework, which evaluates and guides the maturity of symbiotic cooperation within a hub — looking at aspects such as stakeholder engagement, infrastructure readiness, operational coordination, and value-chain integration.
Within the United Circles project, and based on these conceptual stages and the SRLs, three kinds of H4C have been defined:
For more information concerning the levels of maturity of H4Cs and Symbiosis Readiness Level (SRL) framework, and the conceptual stages for H4C, please see section 2.3 of Deliverable D2.2.
An H4C is a collaborative ecosystem: a wide range of actors — public institutions, semi-public companies, large industries, SMEs, start-ups, investors and research organisations — working toward a shared vision of sustainable regional development. A hub succeeds only when these actors collaborate actively, contributing not just resources and expertise but also shaping its governance, decisions and daily operations.
To make sense of such a broad network, it helps to group participants by the role they play. Some drive and use the circular value chains; others enable them. Both are essential.
These are the actors whose materials, sites and know-how make a circular value chain physically possible:
These actors don’t operate the value chain directly, but it cannot develop or endure without them:
Two coordinating roles hold the ecosystem together and operate at different levels.
The Circular Hub Organisation (CHO) is the hub’s central orchestrating body — a neutral, trusted entity responsible for the hub’s overall coordination, strategy and implementation. It connects actors, aligns their initiatives, and enables co-investment in shared infrastructure, knowledge and innovation. The CHO is what gives a hub continuity and a single point of accountability over time. (The CHO’s role is developed further in Circular Hub Organisation (CHO), below.)
The H4C facilitator works at the level of individual value chains. Facilitators initiate, develop and guide specific circular value chains, acting as embedded advisors — bringing the right stakeholders together, integrating technical expertise, and steering a project forward in a structured way. Rather than running projects themselves, they keep the strategic, technical and financial elements aligned so a project stays investment-ready. The role matters most in demonstrator and mirroring hubs, where real-world delivery and replication are the priority, and it is especially valuable for drawing in technical specialists — in waste-stream mapping, bioprocessing or water reuse, say — whose expertise might otherwise sit outside the hub’s governance and planning.
In short: the CHO coordinates the hub; the facilitator coordinates the projects within it.
Steering the whole ecosystem is the Executive Board — the hub’s strategic decision-making body. It keeps the H4C aligned with its mission, vision and objectives; sets long-term strategy; oversees governance; approves major initiatives; and guides key policies. It is typically made up of 7 to 9 senior representatives drawn from across the stakeholder groups — industry leaders, public-sector representatives, research and innovation experts, civil-society and community advocates, and the CHO.
Detailed information about the role, composition, key responsibilities, structure and operations of the Executive Board can be found in section 6.1 of Deliverable D2.2. Moreover, members’ requirements, benefits, commitments and expectations are described in section 6.2 of Deliverable D2.2.
Everything a hub does serves a few strategic objectives: advancing industrial–urban symbiosis, closing resource loops, reducing freshwater consumption, and fostering energy co-generation. The activities that pursue them fall into three categories:
Most of a hub’s joint work is organised around the Feasibility to Finance (F2F) process (Deliverable 2.3)— eight steps that take a circular idea from first concept to an investment-ready proposal. Partners contribute to each step according to their roles, and the work moves through three phases, with each step closing at a shared decision gate that holds the collaboration accountable before it commits more effort or money.
Throughout, collaboration is organised around a clear shared purpose — whether that’s a market, a technology, data, policy and infrastructure, investment, or a cooperative partnership — so every partner understands both what it contributes and why.
Waste mapping (step 2 above) deserves particular attention, because it is the evidence base everything else builds on: you cannot design a value chain around a resource you haven’t reliably quantified. Yet in many regions, dependable waste statistics — especially for end-of-life and residual streams — simply don’t exist. Available data is often fragmented, underestimates real quantities, or can’t be tied to specific sites, which makes symbiosis opportunities almost impossible to spot from statistics alone. The answer is to combine several data sources with on-site collection and validation.
The United Circles waste mapping methodology (Deliverable D2.6) does exactly this, combining top-down and bottom-up assessment to quantify and characterise waste at the level of a site, city, region or country — giving both strategic oversight and the operational accuracy that investment decisions require. It is modular and interoperable, so it can be complemented by geographical mapping and spatial screening (proximity, clustering, logistics), visual inspection (rapid assessment of types and volumes), laboratory testing (composition and suitability for recovery), and sensor-based assessment (continuous monitoring).
The methodology runs through four actions — best treated not as a fixed sequence but as steps practitioners move between to refine the assessment over time:
To help practitioners choose the right combination of methods, D2.6 provides a decision tree: starting from the system boundary, it guides users through a series of questions based on their objective and the data available — whether they need to estimate future waste availability, locate geographical hotspots and symbiosis opportunities, or characterise waste quality for reuse. Like the four actions, it is iterative by design; in practice, robust mapping usually blends top-down estimation, bottom-up validation, geographical analysis and quality characterisation in a single assessment.
A step-by-step guide and a practitioner checklist are included in D2.6.
The Feasibility-to-Finance (F2F) process is more than a sequence of steps — it comes with a practical set of tools and frameworks that equip partners to carry each one out. Tools are the individual instruments a hub uses to map, measure, model and document; frameworks are the structured methodologies that tie those instruments together into a repeatable way of working. None is mandatory: a hub draws on whichever suits the task at hand and the project’s maturity. The tools group naturally into the three phases of the F2F process — Exploration, Assessment and Funding.
In the early phase, the challenge is to work out what is worth pursuing — which resources are available, which technologies could use them, and who needs to be involved.
Readiness and progress tools help a hub judge how mature an opportunity is and whether it’s ready to move forward. The Symbiosis and Technology Readiness Levels (SRL/TRL) provide common maturity scales — the SRL gauging how developed the symbiotic cooperation is, the TRL how proven the technology is — while a phase-weighting system and adaptable stage-gate templates (with KPIs and built-in decision logic) turn each F2F decision gate into a structured, evidence-based checkpoint rather than a judgement call.
Mapping and screening tools build the factual picture on which the whole value chain rests. Waste and resource mapping — using GIS and material- and substance-flow analysis — establishes what materials exist, in what quantities, and where; technology screening, scoring matrices and acceptance tables then narrow the field to the configurations that are technically viable.
Stakeholder tools make sure the right partners are identified and engaged before significant effort is committed. A Theory of Change framework clarifies how the hub’s activities are expected to lead to impact; stakeholder mapping and the power–interest matrix reveal who matters and how to engage them; and stakeholder registers, role matrices and partner due diligence and risk-profiling templates keep roles, expectations and partner reliability transparent from the outset.
Once a promising opportunity is defined, it has to be rigorously tested — environmentally, socially, financially, and against the risks that could derail it.
Impact assessment tools measure whether a project delivers genuine environmental and social value. Life Cycle Assessment (LCA) quantifies environmental impacts across a product or process’s entire life cycle, and Social Life Cycle Assessment (S-LCA) does the same for social impacts on workers and communities. These are supported by established indicator sets and databases — such as the Global Reporting Initiative (GRI) and the Social Hotspots Database (SHDB) — and by dedicated tools such as GRETA, the project’s own life-cycle sustainability assessment tool, which brings environmental, economic and social analysis into a single workflow.
Financial and risk tools assess whether a project is commercially viable and what might go wrong. Financial modelling — net present value (NPV), internal rate of return (IRR) and debt-service coverage ratio (DSCR) — establishes whether the numbers work; sensitivity and scenario analysis stress-test them against changing assumptions; multi-criteria decision analysis (MCDA) weighs options that can’t be reduced to money alone; and structured risk methods such as HAZOP (a hazard and operability study) systematically surface technological, operational and safety risks before they become costly.
The final phase converts a validated project into one an investor can actually back.
Funding and legal tool’s structure the deal and bring partners and financiers together on firm terms. Funding-source mapping matches the project to the right mix of public and private finance; ownership and governance models set out how the venture will be run and how value will be shared; legal instruments — Memoranda of Understanding (MoUs), Letters of Intent (LoIs), Non-Disclosure Agreements (NDAs) and data-sharing agreements — formalise cooperation as it deepens; and investment documentation such as the Private Placement Memorandum (PPM) and financial prospectus packages the opportunity for funders in the form they expect.
Tools tell you what to measure; a framework tells you how to measure it consistently. The clearest example is the Social Impact Assessment (SIA) Framework (Deliverable 2.4), which provides hubs with a structured method for the social side of the impact assessment above — the dimension that circular economy work most often overlooks.
Circular projects are usually judged in technical and environmental terms: tonnes diverted, emissions avoided, loops closed. But whether a project creates good jobs, shares its benefits fairly, and earns the trust of the surrounding community frequently decides whether it succeeds at all. The SIA Framework — developed with all eleven United Circles hubs and designed for use by non-specialists — closes that gap.
It rests on the principle of double materiality: a hub needs to understand both how its activities affect people and communities and how social factors, in turn, affect the hub’s own resilience and legitimacy. Assessing both directions is what moves social impact from an afterthought into a factor in real decisions.
In practice, the Framework concentrates on three mandatory dimensions:
Examines job quality, creation patterns, and skills transition pathways. Quantifies job creation in circular sectors, assesses working conditions, and measures demographic distribution of employment benefits.
Addresses fair access to benefits, services, and decision-making processes. Evaluates how environmental improvements benefit different groups and identifies potential unintended consequences.
Focuses on representation of disadvantaged groups and environmental justice. Ensures less vocal communities are empowered within IUS networks and examines fair distribution ofbenefits and burdens.
It is organised around two interlocking sub-frameworks, one for engaging citizens and community actors (moving beyond consultation to genuine partnership) and one for measuring social impact (with SMART indicators, baseline protocols, and a ‘traffic-light’ system that makes results legible at a glance), both running through a continuous five-phase cycle adapted from the Design Council’s Double Diamond method. It aligns with the EU’s sustainability-reporting landscape (ESRS/CSRD and the European Green Deal) and the UN Sustainable Development Goals.
The Framework comes with a ready-to-use Operational Toolkit and three plain-language booklets — for leaders and funders, for citizens, and for the technical staff and replicating hubs who apply the method.
For more details, see the booklets:
A Hub for Circularity brings together public and private partners with very different resources, objectives and risk appetites. For them to act as one, the way they work together has to be made explicit — through governance (who coordinates, who decides, and how) and through formal agreements (how commitments and contributions are protected). Both share a defining feature: they are not fixed at the outset but mature as the hub does, tightening from loose cooperation into firm structure as a project moves toward investment (Deliverable 2.5).
Most hubs don’t begin with formal governance — they begin as a Community of Practice (CoP): an informal network for mapping stakeholders, exchanging knowledge, and building the first connections among industry, public authorities, research organisations, and civil society. Governance work is the deliberate process of turning that loose network into a coordinated ecosystem, shifting stakeholders from being mapped to taking part — through advisory boards, steering committees, thematic working groups and structured decision-making. A hub’s governance is therefore best understood as something that matures progressively, from network formation, through collaborative planning, to formal structures backed by advisory bodies and clear decision rules.
This is why hubs at different stages look different. Among the United Circles hubs, the demonstrators show the most advanced governance: Ankara runs a structured, technically steered model built around waste mapping and harmonised performance indicators; Veneto uses a flexible, cluster-based structure spanning its entire value chain; Salamanca builds on established institutional partnerships. Mirroring hubs sit at an intermediate stage, adapting these models to local conditions, while seed hubs are still at the foundational stage — defining mission and vision, mobilising stakeholders, and designing the governance they will grow into.
Whatever the stage, effective governance depends on a clear coordinating function. That role belongs to the Circular Hub Organisation (CHO) — the neutral, trusted body, introduced above, that holds the ecosystem together by ensuring alignment, continuity and collective ownership. Many hubs reinforce the CHO with systemic approaches such as Communities of Practice, which map interdependencies and turn fragmented expertise into shared, co-owned action plans.
There is no single right governance model. The H4C Community of Practice study identified six recurring models, but these are neither mutually exclusive nor exhaustive — as hubs mature, hybrid and evolving models are expected to emerge. What matters is not which model a hub adopts but that it has identifiable coordination, transparent decision-making, and inclusive stakeholder representation.
As cooperation deepens, it has to be formalised — and, like governance, the formal commitments harden in step with the project’s maturity.
In the early phases, collaboration can be governed by lightweight, flexible instruments — Memoranda of Understanding (MoUs), Letters of Intent (LoIs), Non-Disclosure Agreements (NDAs) and data-sharing agreements. These build trust and define roles without locking partners into binding commitments before the case is proven, so that uncertainty over roles doesn’t slow progress or deter risk-averse partners.
As a project advances toward investment, these mature into binding, investment-grade contracts that give funders confidence and ensure operational continuity:
Because innovation in industrial–urban symbiosis usually emerges from collaboration — shared technology, co-designed processes, jointly optimised resource flows — ownership and commercialisation must be settled early. A clear IP strategy separates background IP (what partners bring in) from foreground IP (what the project generates), and assigns it through sole ownership, joint ownership or licensing, drawing on standard frameworks such as the WIPO model clauses. Proprietary knowledge is protected through NDAs, confidentiality clauses, IP liaisons and secure data rooms; contributions are formally attributed in patents and publications; and dispute-resolution mechanisms — including a neutral steering committee — are agreed in advance. Agreements must also satisfy funder requirements, such as the Data Management Plan (DMP) that Horizon Europe projects use to balance confidentiality with open-access obligations.
Finally, durable collaboration depends on fairness being built in rather than assumed. Agreements should include explicit fairness and inclusiveness clauses that prevent better-resourced actors from imposing unbalanced terms and safeguard the interests of SMEs, cooperatives and public entities. It is this clarity and equity from the outset that gives partners the confidence to co-invest, share knowledge, and scale the value chain over the long term.
Across the United Circles hubs, one lesson stands out: success depends less on technology than on the quality of governance, stakeholder engagement, and collaborative capacity. The same factors recur as either barriers or enablers.
The most common barriers are limited long-term financing; fragmentation among stakeholders with divergent interests; regulatory and administrative complexity across sectoral boundaries; gaps in data and information-sharing; difficulty sustaining commitment once initial enthusiasm fades; and limited institutional capacity to coordinate.
The strongest enablers mirror them: strong leadership and a dedicated coordinating body (the CHO); active stakeholder participation and trust-building; established collaboration networks to build on; alignment with regional policy priorities; access to research and innovation expertise; and available funding and investment-support mechanisms. Hubs that secure these are far better placed to move from planning into implementation.
A Hub for Circularity asks a lot of the people who run it. Coordinating industries, public authorities, investors and communities — and steering circular value chains from idea to investment — calls for a blend of technical, regulatory, financial and collaborative skills that few organisations have all at once. Building that capacity is itself a core hub activity, and the United Circles H4C Skills Training Programme (Deliverable 2.7) was designed to do exactly that, for project partners and the external stakeholders working alongside them.
The programme was built from the ground up around real needs. Rather than assuming what hubs should learn, the team ran a structured needs assessment — interviews, co-creation workshops and an online survey across the hubs — to identify where the skills gaps actually were. The answers spanned both the technical (energy and material flow analysis, waste mapping, circular business models, financial planning, ESG reporting, regulatory compliance, risk analysis, KPIs) and the human (stakeholder engagement, communication, collaboration, trust-building). The programme was then shaped and refined to match and mirror hubs, so the content fit real regional and sector contexts.
The programme deliberately split its content between two formats, matched to how each is best learned.
Online modules carried the technical, regulatory and business content — the material that works well through expert presentations, case studies and self-paced study. Across sixteen sessions they covered four broad areas: identifying symbiosis opportunities (drawing on Scandinavian case studies and a library of 30+ real examples); analysis and digital tools (energy and material flow mapping, Sankey diagrams, screening platforms); business, finance and compliance (circular business models and the H4C Business Model Canvas, financial planning and the “valley of death,” ESG reporting, risk analysis, KPIs); and circular technologies in practice, including dedicated peer exchanges between hubs on each demonstrator’s specialism — wastewater (Salamanca), food waste (Veneto–Gauteng) and construction and demolition waste (Ankara–Greece).
In-person training in Pécs concentrated on the collaborative competencies that are hard to build online — the ones that depend on doing rather than watching. Three themes ran through it: systems thinking, stakeholder engagement and communication, taught through group exercises, stakeholder mapping, role-play, and hands-on value-chain and waste-mapping work, supported by causal-loop diagramming and the Vensim modelling tool.
The single most important finding of the co-design process was that systems thinking is the competence that ties all the others together — and it became the backbone of the in-person training. At its core, it means seeing a hub not as a set of separate problems but as one interconnected system, where resource flows, technologies, stakeholder relationships and decisions all affect one another. That perspective is what lets a hub coordinator anticipate trade-offs, spot leverage points, and make decisions that hold up across the technical, environmental, economic and social dimensions at once. Participants applied it directly — mapping their own hubs as systems, tracing feedback loops, and working through real decisions such as the TEPE Betopan industrial case.
Evaluation showed high participant satisfaction and confirmed the value of the blended, exchange-driven approach. The clearest lessons for future rounds: allow enough coordination time, build in peer exchange between hubs as a core feature rather than an add-on, and provide additional support for topics that demand hands-on implementation. Together, the programme provides a foundation for strengthening hub capacity and supporting the long-term scaling of circular economy approaches across regions.
