Adapting our approach to historic building conservation in a changing climate

According to Historic England research, 21% of England’s domestic building stock pre-dates 1919. Around 500,000 buildings in England are protected by statutory listing and hundreds of thousands more are situated in around 9,900 conservation areas. The UK has many best practice examples of how historic buildings can be reused and integrated with modern development. However, the process of adapting them to be more energy-efficient and resilient is challenging, especially considering the need to create beautiful places that meet the needs of current and future communities.

This is a national issue that needs to be addressed if the Government’s commitment to net zero is to be achieved; particularly given the contribution the historic built environment can make. Historic England recognises these buildings are important sources of embodied carbon (all the carbon emissions from construction materials, the building process, use of internal fixtures/fittings as well as eventual demolition). In a 2020 study, Historic England also highlighted the substantial impacts that can be made through retrofit, and states that in domestic buildings these could amount to between 54% and 84% of operational carbon savings. The carbon savings associated with adaptations to historic buildings are therefore potentially vast.

Historic buildings provide meaningful connections to the past, add character to our streets, and make beautiful, atmospheric places in which we want to live, work and visit. The fact that it was once common practice to adapt such buildings to meet the needs of the changing seasons is generally forgotten in today’s planning regime. Actions such as installation of awnings to cover sunny windows to prevent overheating in the summer months and panelling internal walls for heat retention in the winter, are no longer commonplace. Arguably, we no longer routinely make the best use of the adaptable qualities of historic buildings.

Continued adaptation, particularly as whole-life carbon values diminish over time, will both sustain heritage assets, mitigate global warming, and make communities more resilient. That said, any adaptation in the historic environment needs to be done intelligently. Essentially, this means any interventions on a historic property would respect its ‘significance’ (as defined by the National Planning Policy Framework or NPPF as the value placed on the property’s ‘historic, architectural, artistic or archaeological interests’) whilst also reducing operational carbon emissions.

Retrofit schemes which deliver substantial carbon emissions and energy consumption reductions are achievable in highly sensitive Grade I Listed Buildings, which are often perceived to be too precious to be altered. An example of this is New Court, Trinity College, Cambridge.

However, there will always be the risk of inappropriate interventions. For instance, the replacement of original single-glazed timber-framed windows with modern uPVC is unlikely to be considered appropriate from a planning or conservation perspective. Despite the issues associated with this ‘hot topic’, there are many options available to owners when seeking to improve the thermal efficiency of their windows.

Overall, I believe that there are some fundamental changes that could be made to ensure the potential of the historic environment to help tackle the climate crisis is harnessed:

• Create a much stronger direct link in the NPPF between heritage protection and environmental sustainability and include policies for carbon reduction concerning all existing buildings, including listed buildings
• Bridge the theory-practice gap between heritage protection legislation and policy at a national and local level
• Create a holistic strategy for decarbonising traditional buildings as part of the UK’s overarching net-zero strategy
• Improve the availability of clear guidance, expert advice and supply chain skills resources