Retrofitting UK Historical Buildings: A Path to Achieving Net Zero
As the world moves closer to global net zero targets, is retrofitting historical buildings the answer to achieving this?
In the UK, one-fifth of greenhouse gas emissions originate from buildings, with historic structures posing some of the most challenging obstacles to overcome. While retrofitting seems like a straightforward solution to making existing and heritage buildings sustainable, energy-efficient, and compliant, numerous barriers and challenges must be addressed to realise its full potential.
Building life cycles
Retrofitting UK historical buildings presents a complex challenge, often requiring the integration of modern services and equipment into old structures. While this process may not necessarily be cheaper than constructing a new building from scratch, it is crucial to consider the broader perspective and the building's existing state. Historical buildings embody a significant amount of energy and have a carbon footprint associated with their creation. Therefore, it is generally more environmentally advantageous to work with the existing structure rather than starting anew.
Although the cost of retrofitting may be higher, the long-term benefits in terms of the building's overall life cycle, efficiency, and environmental impact are substantial. A noteworthy project undertaken in collaboration with the University of Manchester serves as an exemplary case of extreme retrofitting. In this particular project, only the concrete frame of the original building remained intact. The project showcased the potential to reuse the disembodied carbon within the structure, thereby preserving and extending the building's life cycle. While this approach may not have been the cheaper alternative, it undoubtedly yielded a far greater positive environmental impact.
By retrofitting historical buildings and repurposing their existing elements, we can tap into the embodied energy and carbon of these structures, contributing to the achievement of net zero goals. Retrofitting allows us to honour the heritage and architectural significance of historical buildings while simultaneously reducing their environmental footprint.
Looking beyond the obvious
The scope of retrofitting extends beyond individual buildings to encompass a wide range of projects. From converting old mills into functional structures to repurposing farm buildings into contemporary dwellings, retrofitting presents immense opportunities for the UK. By collaborating with housing associations, efforts are underway to enhance the insulation of managed homes, while technologies like air source heat pumps and solar PV systems are increasingly employed to strengthen the retrofit output.
A report by The National Trust, Peabody, Historic England, The Crown Estate, and Grosvenor highlighted the necessity for substantial growth in the low-carbon economy to support the UK's net zero goals. The construction industry, therefore, plays a pivotal role in transitioning to a green economy. This transition requires a significant increase in the industry's workforce, with the Construction Industry Training Board (CITB) estimating that around 350,000 additional workers will be needed in the late 2020s to achieve net zero in the built environment. Meeting such demands necessitates attracting new talent and retraining individuals already in the sector.
However, challenges arising from the pandemic and Brexit have led to skills shortages and labour supply issues in the construction industry since the beginning of 2021, exacerbating an already aging workforce. Specifically focusing on the skills gap in retrofitting historical buildings, an analysis by Capital Economics reveals that an additional 105,000 full-time workers would be required annually until 2050 to retrofit historic buildings, in addition to the existing 100,000 professionals associated with retrofitting historic properties. Without an adequate workforce, the industry and the UK as a whole risk falling behind on net zero targets, creating project backlogs, and losing invaluable cultural heritage as buildings remain non-compliant and uninhabitable.
Training and apprenticeships
A comprehensive program of specialised skills training is essential. Retrofitting historic buildings requires unique knowledge and expertise. To bridge the skills gap in the retrofit sector, it is crucial for the public and private sectors to come together. The Heritage and Carbon report recommended the establishment of a National Retrofit Strategy, which would represent a significant step forward in delivering consistent, standardised training for both new talents entering the sector and upskilling existing professionals in associated fields. Involving individuals with specific sector skills in the development of robust training programs is vital to create a long-term talent pipeline capable of meeting the UK's retrofit and green economy requirements.
Another avenue to explore is apprenticeships. Attracting and nurturing young talent presents a tremendous opportunity for the retrofitting industry, as apprentices can become invaluable assets to the sector and the future of construction in the UK.
To fully harness the potential of retrofitting, it is crucial for the government to incentivise such schemes. Greater emphasis should be placed on encouraging individuals to prioritise environmental impact over cost considerations. This can be achieved through tools like the Building Research Establishment Environmental Assessment Method (BREEAM), which assesses the sustainability and performance of buildings. Showcasing the benefits of the retrofit approach will help raise awareness and recognition of the value inherent in existing structures. Rather than resorting to the energy-intensive process of brick manufacturing, where tonnes of clay must be dug and fired, retrofitting allows us to make use of the materials already incorporated into the buildings around us.
The role of building control
Given the intricate nature of retrofitting historical buildings, engaging with experienced building control providers at an early stage is vital. These specialists possess the knowledge and expertise required to navigate the complexities and meet the regulations and requirements associated with such projects. Contacting a provider only a month before the start of construction is far from ideal. Their insights and guidance are indispensable and should be sought as early as possible.
If the UK aims to achieve its net zero targets, retrofitting must play an integral role in the transition. Relying solely on new construction or the replacement of inefficient buildings is insufficient to meet the necessary pace and scale. To fully unlock the benefits of retrofitting, urgent attention must be directed towards addressing the skills challenges faced by the sector. Simultaneously, efforts should be made to raise awareness and promote the adoption of retrofitting practices based on their positive environmental impact. By embracing retrofitting as a key strategy, the UK can embark on a transformative journey towards a sustainable and energy-efficient future.
John Miles is Business Development Director at Assent