An estimated 80% of today’s buildings will still be in use in 2050, which just goes to show the importance of prioritising retrofit if the UK is to reach its net zero carbon ambitions.

So what are the realities of retrofit? At UKREiiF, we hosted an expert panel in partnership with Assura plc, to debate the challenges and opportunities of retrofit projects, and explore how they can contribute to reducing carbon emissions and tackling climate change. Our panellists included:

• Paul Warwick, director of sustainability and projects at Assura plc
• Louisa Bowles, partner and sustainability lead at Hawkins\Brown
• Julian Broster, our co-founder and managing director at Civic Engineers
• Ruth Oates, director at Buro Four

To kick off the discussion, Joshua Hammond, account director at Social and our panel chair, asked the panellists what the concept of ‘retrofit’ means to them:

Julian Broster: “To ‘retrofit’ means a lot of different things to people. To us at Civic Engineers, we think of it as reimagining or repurposing a building. The term ‘retrofit’ itself perhaps isn’t the best way to describe the extent of our ambition when it comes to reuse, with ‘retro’ suggesting that we’re trying to repair a building and take it back to what it was used for originally. What we’re really striving for is to look towards the future, often with a new purpose for the asset. It’s about falling back in love with a building and finding new uses for it.”

Ruth Oates: “I see retrofit as working with the existing buildings we already have, and repurposing them for what we need them to do today and tomorrow. It might be a simple refit, or a complete cut and carve, or replacing a façade. There are so many brilliant examples of it in action, such as the transformation of the historic Royal Academy of Arts in London in time for its 250^th anniversary. It’s whatever we need to do to make that building useful, and it’s vital as an urgent response to the climate emergency.”

Paul Warwick: “Retrofit is a relatively new term in terms of the context of net zero carbon pathways. There are two different types of ‘retrofit’. The first is ‘light retrofit’, which is anything that doesn’t affect the structure of the building, such as building optimisation or updating its fittings to be more efficient.

“’Deep retrofit’ is anything that goes beyond that, such as a series of multiple interventions to achieve net zero carbon. It involves exploring how the building actually functions, looking to decarbonise and monitoring the building in a lot more detail. As Assura plc, we’re invested in the long-term future of properties and hitting our ambition of net zero across our portfolio by 2040. Retrofit has a huge role to play in this, which is why we’ve published our Net Zero Carbon Guide and worked closely with the UK Green Building Council (UKGBC) to accelerate commercial retrofit.”

Louisa Bowles: “The culture of our built environment today and retrofit is absolutely fascinating. We’re still educating our graduates in the beauty of modernism, and that shiny and new is better. Celebrating every era of buildings really needs to be baked in from a career point of view. Retrofit means that we’re developing our built environment to be better and not just knocking it down.”

Our panel moved on to explore whether the industry has the requisite skills to drive the retrofit agenda:

Ruth Oates: “Large projects can take years, even decades, and retrofit is a creative process. Discoveries along the way are inevitable, so it’s vital you allow for the unexpected and have a team of creative thinkers who can adjust. Knowledge, education and having a whole range of complementary skills on a project are crucial.”

Louisa Bowles: “It’s all a communication piece. You often need to peel back several layers of past interventions, so that you can understand what the original design intent was. Sometimes this is really sound and the retrofit is enhancing this with current technology and strategies. Working with existing buildings can get technical very quickly, so at the beginning it’s how you communicate the bigger vision and take people with you at the right pace. Before the decision making gets more mundane.”

Joshua steered our panel to discuss capability in the industry and outlook for the future:

Julian Broster: “In terms of regulation, it’s a matter of ‘when’ not ‘if’. Regulations that limit embodied carbon are going to be introduced, it’s just a question of time. The carbon emissions bill started its passage through the Westminster parliament in 2022. You would hope that the next five years may see progress. Whole life carbon regulation will create a sea change in the industry.

“As Ruth says, there are many surprises along the way when it comes to retrofit. Many are positive, as we have seen with one of our projects to refurbish the former House of Fraser on London’s Oxford Street into a mixed-use destination known as The Elephant. There, we are reusing pre-WWII steel salvaged from the site for a new, separate London office scheme next to Tower Bridge by FORE Partnership. It’s a really visionary, collaborative project.

“It’s not just buildings.  At Mayfield Park in Manchester, a key part of the development involved the de-culverting of the River Medlock, which had been hidden under a concrete and iron culvert for more than 50 years. Retrofit includes opening-up the fabric, and we need to be alive to what might be uncovered – it’s important to keep an open mind and be creative.  At Mayfield we re-used the original iron beams for new bridges, with substantial carbon savings, as well as creative re-use of the industrial heritage.”

Paul Warwick: “We see there’s a huge role to play for developers and investors to drive the retrofit agenda forwards. While the barriers to retrofit are still significant from an economic and commercial viability perspective, the business case clearly stacks up for us in terms of the wider impact.

“As Julian says, if you have a structure at the heart of a city or town that can be reused, it has a broader impact on the community and local economy. Repurposed buildings can revitalise high streets and are often already well connected with pre-existing transport links. We should see it as a huge opportunity to have greater positive impact.”

Louisa Bowles: “Not only does retrofit decrease carbon emissions, it’s also about enhancing the human experience. It has a clear benefit to all, and we’re increasingly seeing demand for analytics and embedded strategies to back up decision making. We previously launched a tool, H\B:ERT (Hawkins\Brown Emissions Reduction Toolkit) to visualise the embodied carbon of buildings and have just re-worked this into VERT. This is intended to be a commercial tool, available this year with an early stage, existing building module included to allow non-experts to make decisions around building retention and depth of retrofit using estimated energy and embodied carbon as decision making drivers.

“On a policy level, the regulatory position must be strengthened and enforced to change the current lack of commitment at the speed and scale which is required to reduce emissions. While Part Z (the industry-proposed amendment to regulations to introduce mandatory whole life carbon reporting to report Whole Life Carbon and move towards limits) has stalled, the impact it would have if and when it is introduced is seismic.”

Ruth Oates: “We’re in a hugely privileged position to effect change. Our industry has an enormous impact on the environment, which is why retrofit is so critical.”

Thank you to our panellists for taking part in the discussion.