Decarbonising historic towns and cities: Lessons from Oxford and Cambridge

Our Head of Sustainability, Laura Baron, draws out the common themes and considers how they might inform approaches in other historic places.

Oxford and Cambridge face similar decarbonisation challenges. Both cities are internationally recognised centres of learning, research and architectural heritage; both contain dense historic estates, collegiate ownership structures and diverse building portfolios whose continued use and enjoyment is intrinsically linked to their cultural value. Both have recognised the need to reduce carbon emissions, with city-wide net zero ambitions outpacing national targets: Oxford by 2040 and Cambridge by 2030. Delivery, however, is complicated by heritage significance, infrastructure constraints, costs, complex governance and land ownership. Even so, progress is being made, and conversations have moved beyond ambitious targets towards practical action and measurable delivery.

Heritage as asset or constraint?

In both Oxford and Cambridge, architectural heritage is considered a source of great pride but also a major practical barrier. Listed buildings, conservation areas, complex sites and inconsistent priorities between climate goals and heritage conservation slow down decision-making. Many argued the need for decision-making to become ‘heritage informed’ rather than ‘heritage led’, suggesting a need to protect significance without allowing conservation processes to prevent proportionate adaptation.

Conversations in both cities highlighted the need for a clearer understanding of where heritage significance lies, so that owners, planners and design teams can make confident decisions about where change is acceptable. In both cities, it was agreed that heritage need not be a barrier to decarbonisation. Like all historic towns and cities, Oxford and Cambridge have adapted continuously over time, and this moment is no different. Conservation and climate action share a common goal: safeguarding our inherited world for future generations. They must be reconciled rather than opposed.

From estate-wide strategies to building-by-building delivery

In both Oxford and Cambridge, there has been a clear move away from fixed, often arbitrarily set dates for achieving net zero ambitions across a whole estate towards a more nuanced, building-by-building approach that sets clear outcomes against a deliverable plan. This starts with a detailed understanding of a building or buildings, including a thorough assessment of heritage significance, essential for identifying where change is most likely to be acceptable. Knowledge of existing building performance can also inform proposed measures and ensure investment is targeted where interventions will have the greatest impact. Examples included installing simple sensor technology to monitor environmental conditions on a room-by-room basis, then using the data to prioritise interventions and benchmark results.

Fabric first or technology driven?

A noticeable shift has been moving away from a pure focus on fabric-first interventions. Whilst fabric is still considered an essential component (particularly when it comes to repair, ongoing maintenance and no-regrets upgrades), the rapid improvements in technology, coupled with the cost and disruption associated with extensive fabric-focused retrofits, are often steering proposals toward more technologically-led solutions.

While this approach is often driven by multiple constraints, including viability, heritage, operational and spatial challenges, there are risks. Missing opportunities to capture the benefits of more passive solutions can lead to higher operational costs if energy demand is not reduced. It can also increase the maintenance burden where new and complex technologies rely on specialist expertise.

A more holistic approach brings added benefits which should not be overlooked. Upgrading fabric performance can improve occupant comfort without the need for energy intensive interventions. It can also support behavioural change where solutions are straightforward, such as opening a window rather than controlling complex cooling units. Reducing energy demand can lower long-term costs and improve energy security by limiting reliance on national grid capacity.

Beyond the red line boundary

Across all conversations, there was a recognition that individual institutions are often solving similar problems separately, and that decarbonisation is too complex to be solved site by site. Participants called for greater sharing of strategies, particularly where adjacent sites could collaborate, share resources and skills, and exchange lessons from pilot studies and completed schemes. There is a need for neutral spaces where owners can share lessons, discuss failures and develop common approaches. Key takeaways included involving contractors and local authority planning officers earlier on and more actively, pooling knowledge on funding mechanisms and business cases, and developing shared approaches to common technical issues such as window upgrades.

The role of heat networks

Both cities acknowledged the role of emerging strategies for city-wide district heat networks. There was a growing consensus that these networks are a key part of decarbonising historic centres but are not a standalone ‘silver bullet’. Some institutions are waiting for clarity on progress and delivery, some see connection costs as prohibitive, especially when set against comparative costs for site-specific solutions. Consideration for how new energy centres could become thoughtful additions to the city was seen as critical, as was clear, transparent communication.

Language matters

In both cities, conversations turned to the importance of language. Terms such as ‘net zero’ and ‘decarbonisation’ were sometimes seen as abstract and unhelpful. In Oxford, the issue was framed as a broader question of how to build collective will around achieving net zero across the city, supported by better communication, an emphasis on health and wellbeing, and consideration for future generations in decision-making. Cambridge’s challenge was framed more around implementation: how to define achievable deliverables within a realistic timeframe. Some estate owners are moving away from high-level net zero targets in favour of terms such as ‘degassing’, which are seen as describing more tangible actions.

Funding, skills and capacity

The loss of Salix funding, high delivery costs, limited contractor capacity and lack of specialist skills were all cited as stalling progress. Some of these concerns were framed as opportunities, calling for investment in local skills, apprenticeships and traditional trades so that decarbonisation can support a fairer and more resilient local economy. Overall, there was an agreement that upfront capital expenditure needs to be balanced against the broader benefits of climate action. Whilst it may not automatically generate a financial return in the short-term, viable delivery depends on understanding costs, benefits, risks and priorities over time, supported by a stronger understanding of the benefits to human health, local economies, skills and the creation of more resilient communities.

A lesson in leadership

Decarbonising historic cities requires a whole-place approach. Individual buildings matter but the challenges are systemic: planning, infrastructure, skills, funding, consent, data, public understanding and institutional governance. Decarbonisation is not a single project or technology, it is a long-term cultural, technical and institutional transition. The most effective response will combine building-level evidence with city-level collaboration. As leaders in this conversation, Oxford and Cambridge are already demonstrating how historic cities can champion climate action: not by choosing between heritage or carbon reduction but by showing how each can strengthen the other as part of heritage’s continued evolution. Done well, decarbonisation can make our historic places healthier, more resilient, more affordable to operate and more relevant to future generations.