The transformative power of regenerative retrofitting

As the weather starts to turn and winter looms near, many of us are turning our minds to our homes and what this winter will bring. From cold draughts to freezing conditions that lead to burst pipes, and dialling the radiators to maximum leading to inevitably high energy bills, winter brings lots of domestic challenges. And, for some of us, this includes increased health challenges as the cold seeps into our homes and bodies.

While minimising the negative impacts on the environment is a commendable shift, simply being “less bad” is not enough. In the face of accelerating climate change, biodiversity loss, resource scarcity, and social and health inequity, could ‘retrofit’ be the lever we need to shift our approach from sustainable (doing less harm) towards regenerative development (doing net positive good)? This is a question our practice is increasingly interested in as we see the shift in client interest and resulting briefs.

We recently completed our own home retrofit and experience the daily benefits, even though it does not meet EnerPHit standards. From staying at a relatively cool 21°C in summer while many of our friends and family had homes that overheated in the 33°C heat, to now, coming in from a 10°C cool morning walk to a stable 20°C home and wandering if the heating has been turned on – it hasn’t, our home just retains its heat much better than it did 18 months ago.

However, even more importantly is the personal impact; as an asthmatic, I don’t need to use my inhaler nearly as much as I did in our previous home (built in the early 2000’s). This improvement to my daily health, more than anything else, is priceless – and as a result, enables me to think of home as a place I can heal, recover, regenerate.

We are not the only ones now slightly obsessed with building performance, we find that many of our clients (both public and private sector) are more interested too, with the conversations we have shifting from new build to retrofit for the conservation of heat, energy, bills, carbon. Our clients are becoming more sophisticated in the briefs they are setting – being more collaborative and discursive in a bid to consider health and planet as key stakeholders.

The benefits of a paradigm shift from sustainable towards regenerative are plentiful

We know only too well that the UK has some of the most energy inefficient homes across Europe, and that 80% of the homes that are going to be around in 2050 have already been built. With 26 million homes needing retrofit, and circa 3.78 million homes in London alone, retrofit must become the default to achieve a zero-carbon economy.

Critically though, adopting regenerative principles allows us to adopt systems thinking in bringing a more holistic approach to this retrofit revolution. Beyond a singular focus, systems thinking allows us to understand challenges as interrelated and interdependent (such as warmer homes leading to less asthma attacks in the winter months).

The benefits of a paradigm shift from sustainable towards regenerative are plentiful. Aiming to become net positive encourages us to think widely about resource recovery by transforming waste into resources and making it part of our circular economy. By reducing noise levels in our cities we can help restore local fauna and flora, contributing to local and global biodiversity gains. Participatory design that includes communities can help empower people through the planning and maintenance stages of development.

Economic benefits range from long-term energy savings, to new sources of income such as food or energy production. And by imbuing communities with greater resilience through regenerative design principles, they can become better equipped to deal with environmental and social shocks, thereby saving costs in the long term.

Most powerfully though, regenerative development promotes ethical responsibility such as stewardship: rather than viewing humans as separate from or above nature, regenerative design views humans as stewards of the ecosystem. This shift in perspective underscores the ethical responsibility to do more good, rather than just reduce harm.

Embracing a regenerative approach will require us to understand our existing buildings in a more intimate way than we currently do, and respond accordingly. While individual homes present initially as unique, there are clear threads that allow us to target interventions most effectively.

Understanding if a house was built pre 1919 or post 1920’s helps us know if we could retain breathability of the fabric. Most buildings will have some type of modification or maintenance over the years; a new rear extension that might have insulated cavity walls, behaving quite differently from the original solid wall construction that hasn’t been insulated.

Personally, this is where I find the joy in the challenge lies; in understanding a building’s physics; how vapour moves through the fabric, it’s impact on structure and on human health (mould, respiratory challenges, etc), and how we fix these problems. We know that thermal bridging can account for 20-30% of heat loss in new builds (let alone existing ones) yet measuring psi-values is a topic architects are still working through - even if we talk about a fabric-first approach.

We know the risk of interstitial condensation with varying internal surface temperatures, yet we don’t undertake WUFI calculations and make different design decisions accordingly. We know the carbon impact of using certain types of materials and insulation, yet we are still nervous to explore more natural options that sequester carbon. We hear the complaints (and experience) overheating every summer, yet don’t sufficiently address solar gains and ventilation.

With 2030 rapidly approaching, the solutions exist, and perhaps now is the time for us to explore retrofit as the lever to make more systemic change to regenerate our people and planet. We could start by using and refining frameworks like the Living Building Challenge by the International Living Future Institute (ILFI). Our industry is known, notorious even, for being slow to change, but could a new retrofit dawn help us change this narrative?

For us, our deep retrofit has been transformative and as a result, the practice undertakes robust early-stage energy evaluations that include thermal bridge assessments and condensation analysis to aid building performance decision-making. We iterate design ideas measuring embodied carbon and operational energy so we can best advise clients.

The best part of it all is that we tend to let the science speak for itself and the soundest decisions almost always make themselves. As a result, we are finding that more of the retrofit projects we undertake have a phased approach to delivery, and I expect this trend will continue to rise.

While we can’t underestimate the myriad decisions that we must contend with when building better, from capex cost to behaviour change, policy to metrics, I believe that by taking a comprehensive and long-term view, the retrofit industry can be the lever that transforms the traditional “business-as-usual” sustainable model into one that can be regenerative; enhancing the built and natural environment so we can thrive.