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Cambridge Heat Network

Cambridge, UK

By bringing together deep technical expertise, long-standing experience of heat networks, and a collaborative approach to governance and funding, º£½ÇÊÓƵ is helping Cambridge take a decisive step towards decarbonising heat at a city scale in a project commissioned by Cambridge City Council as part of its .

The Cambridge City Centre Heat Network is an ambitious project that responds to the city’s unique academic, civic, and heritage context, providing a coordinated low-carbon alternative to fragmented, building-by-building solutions.

Commissioned by Cambridge City Council and developed in close partnership with the University of Cambridge, Anglia Ruskin University, and 17 Cambridge colleges, the project focuses on delivering a resilient, affordable, and future-ready heat network for some of the most iconic and constrained buildings in the UK. º£½ÇÊÓƵ is leading the detailed technical development of the scheme, alongside the preparation of an Outline Business Case, supporting the client and partners in moving from strategic ambition to a deliverable solution.

At its core, the project recognises a fundamental challenge facing historic city centres: while the imperative to decarbonise is clear, the practical constraints of heritage, space, planning, and infrastructure make individual low-carbon retrofits extremely difficult. The proposed heat network offers a shared solution, enabling institutions to transition away from gas-fired systems while respecting the fabric and character of the city. When complete, the network will provide around 37MW and 73GWh/year of annual heat demand through an integrated system of low-carbon heat sources, serving up to 48 connections across the city centre as part of an initial Minimum Viable Product, with the potential for future expansion.

Challenge

Delivering a heat network in the heart of Cambridge presents an unusually complex set of challenges. The city centre is characterised by dense development, narrow streets, sensitive heritage assets, and limited available land, all of which place significant constraints on both energy generation and distribution infrastructure. Many of the participating colleges and institutions occupy listed buildings, where traditional decarbonisation approaches such as roof-mounted air source heat pumps are often impractical or unacceptable from a planning perspective.

Spatial constraints were a defining challenge from the outset. Identifying suitable sites for energy centres capable of delivering heat at scale required careful assessment, negotiation, and creativity, with each potential location presenting its own limitations. At the same time, the scale of the network, including approximately 8.2km of underground pipework, raised complex questions around constructability, utilities coordination, and disruption within a busy city environment.

The diversity of stakeholders added another layer of complexity. The project brings together Cambridge City Council, two universities, and multiple autonomous colleges, each with different operational priorities, governance structures, risk appetites, and decarbonisation timelines. Many stakeholders also have a high level of technical expertise in-house, resulting in a strong emphasis on transparency, evidence, and scrutiny throughout the decision-making process.

In parallel, the economic case for the project needed to be robust. The proposed delivery model, based on a special purpose vehicle jointly owned by the Council and the institutional partners, required the network to meet relatively high equity return expectations. Securing external funding, particularly through the Green Heat Network Fund, was therefore critical to ensure affordability and viability, while maintaining the project’s ambitious carbon reduction targets.

Solution

º£½ÇÊÓƵ addressed these challenges through an integrated, multi-disciplinary approach that balanced technical rigour with careful stakeholder engagement. Rather than relying on a single heat source, the team developed a hybrid energy strategy that responds directly to Cambridge’s spatial and heritage constraints. The proposed solution combines river source heat pumps drawing energy from the River Cam, air source heat pumps located at multiple sites, and gas-fired boilers to provide peak and resilience cover in the early phases, with a clear pathway to full electrification over time.

This distributed approach allowed the team to make best use of available sites, avoiding over-reliance on any one location and creating a system that is both flexible and resilient. Detailed modelling demonstrated how the network could achieve up to a 93% reduction in operational carbon emissions compared to existing gas boiler systems, while remaining technically and economically viable.

To support engagement and decision-making across a large and diverse group of partners, º£½ÇÊÓƵ led a highly structured programme of stakeholder engagement. The team visited every participating college and institution, undertaking detailed site assessments and working with local facilities teams to understand existing plant, replacement cycles, and connection readiness. This information was distilled into concise, tailored system inventories for each stakeholder, clearly setting out options, constraints, and implications.

Decision-making was supported through a clearly defined governance structure, including regular core group meetings with representatives from the Council, universities, and colleges, alongside engagement with an expert advisory group of academic specialists who provided independent technical scrutiny. This process ensured that the proposed solution was not only technically sound, but also trusted and understood by those who would ultimately own and operate it.

Alongside technical development, º£½ÇÊÓƵ is leading the technical input to the Green Heat Network Fund application, working closely with financial and commercial advisors to align engineering decisions with funding eligibility and business case requirements. This has involved close coordination across disciplines including energy, infrastructure, water, acoustics, air quality, , and working closely with Allies and Morrison on energy centre architecture, ensuring that issues such as river abstraction, cold air plumes, noise, and planning considerations are addressed from the outset.

Value

º£½ÇÊÓƵ’s value to the Cambridge Heat Network lies not only in technical excellence, but in the ability to integrate engineering, economics, governance, and stakeholder priorities into a coherent and deliverable plan. The team has provided trusted leadership at a critical stage of the project, helping the client and partners to navigate risk, complexity, and uncertainty with confidence.

Through rigorous option appraisal and whole life thinking, º£½ÇÊÓƵ has demonstrated how a coordinated heat network can outperform individual building-level solutions on cost, carbon, and deliverability, particularly in a heritage-rich environment. The development of a Minimum Viable Product has given partners clarity on what can be delivered now, while preserving flexibility for future expansion as new sites and opportunities emerge.

The depth of stakeholder engagement has been central to building consensus across institutions with very different needs and constraints. By translating complex technical information into clear, site-specific insights, the team has enabled informed decision-making and strengthened commitment across the partnership.

Crucially, º£½ÇÊÓƵ’s experience of successfully delivering heat network business cases and funding applications has positioned the project strongly for investment. By aligning the technical strategy with the requirements of the Green Heat Network Fund and the proposed ownership model, the team is helping to unlock the external funding needed to make the scheme viable.

Together, this work lays the foundations for a transformational piece of city infrastructure: one that reduces carbon, protects heritage, supports institutional collaboration, and creates a scalable blueprint for low-carbon heat in historic urban centres across the UK.