Why this conversation matters

The built environment is responsible for around 40% of global carbon emissions. For years, sustainability in construction has meant counting emissions, writing reports, and checking boxes. But what if the real story isn’t in the footprint we leave behind — it’s in the handprint we create?

This week’s conversation explores that shift with The Responsible Edge host Charlie Martin and Useful Simple Trust’s Head of Sustainability, Carrie Behar.

The origin of a responsible mindset

Carrie’s turning point came early. As a young architecture graduate in 2009, she joined a master’s course in environmental design. The first assignment? Calculate her own carbon footprint.

“I’d just spent a year travelling the world,” she laughed.

“My flight emissions wouldn’t fit on the page.”

That moment turned embarrassment into action. She realised how every individual decision — no matter how small — plays a part in shaping our shared impact.

From student to systems thinker

Fifteen years later, Carrie leads sustainability across the Useful Simple Trust, a group of purpose-led design and engineering firms. Her role bridges two worlds: guiding the Trust’s internal transition to net zero, and advising clients on how to design for regeneration.

That balance keeps her grounded. “We can’t ask clients to do something we’re not doing ourselves,” she says.

“Implementing change in-house makes me a more pragmatic consultant.”

Compliance or change?

The discussion centres on a Financial Times article about a surge in ESG regulation. Carrie recognises the tension between the growing focus on compliance and the slower work of transformation.

She admits that smaller teams like hers could spend all their time measuring emissions and writing policies. “It can feel bureaucratic,” she says.

“But a clear strategy is the hook from which everything else can hang.”

By doing the heavy lifting on data and governance, her team frees others to innovate — a reversal of the usual model.

The handprint idea

Carrie’s proudest initiative reframes the entire question of impact. Rather than measuring only the carbon footprint of the organisation, Useful Simple Trust now measures its handprint — the positive influence of its projects across society and the environment.

“Our footprint is small,” she explains, “but our handprint — the ripple effect of our work — is where our real impact lies.”

The tool maps each project along a regenerative design spectrum, forcing the team to be brutally honest about both benefits and harms. It’s data with a conscience.

Responsibility in practice

Carrie sees success not as one department’s progress, but as collective engagement. Her favourite metric is the growing number of colleagues applying for the Trust’s R&D and pro bono investment fund.

“I’d rather everyone does a little bit,” she says, “than just a few people doing a lot.”

This bottom-up model turns sustainability from a policy into a practice — one that belongs to everyone.

Hope for a regenerative future

Asked what she’d change about the business world, Carrie offers two wishes: to measure success beyond financial value, and to give nature a literal voice in decision-making.

At Useful Simple Trust, that might soon mean a board agenda item titled “What would nature say?”

It’s a small but profound shift — from counting emissions to considering ethics. From footprints to handprints.

When Saul talks about the future of construction, he doesn’t start with solar panels or smart tech. He starts with timber, hemp, stone, and an uncomfortable truth: we are building on a planet with limits.

As Senior Vice President of The Chartered Institute of Building, a professor of sustainable construction, and the managing partner of a certified B Corp consultancy, Saul has seen every side of the industry. His message is simple but powerful: the greenest building is often the one we don’t demolish, and every fraction of a degree of warming we prevent still matters.

Rethinking Value

For Saul, the conversation about sustainability has to start with something most executives understand: money.

Most appeals to “do the right thing” don’t change boardroom behaviour. But when framed in terms of long-term value, the case for sustainable choices becomes harder to ignore.

“Telling someone they must be more sustainable isn’t that compelling. If you can link it to value—whole-life cost, premium asset value, avoiding stranded assets—then you can shape a commercially sound reason to do the right thing.”

This is where his own career has taken him. Starting out at sixteen on a Youth Training Scheme, Saul worked his way up through hands-on delivery roles before moving into senior leadership. Today, his consultancy is focused on proving that sustainable construction is not just good for the planet, but also good business.

The Carbon We Forget

The building industry often celebrates its progress on energy efficiency and renewables. But Saul says that is only half the story.

Most of the carbon footprint is not in heating or lighting, but in the materials themselves.

“As the grid decarbonises, embodied carbon becomes the heaviest footprint.”

Concrete, steel, and bricks carry huge emissions before a building is even occupied. To tackle this, Saul champions alternatives such as cross-laminated timber, glulam, hemp, stone, and rammed earth. These options are not just theoretical; many are proven and available today.

Fear After Grenfell

Despite these options, the industry has been slow to change. Saul points to the aftermath of the Grenfell tragedy as one reason why.

The disaster made companies and regulators retreat into what felt safe: concrete, brick, and steel. While that caution is understandable, Saul argues it has gone too far.

“In domestic two-storey homes there’s absolutely no reason we shouldn’t be using more bio-based materials.”

The barriers now are less about safety and more about regulation, insurance, and supply chains. To move forward, costs must be assessed across the entire life of a building, not just the cheapest upfront option.

Retrofit Before Rebuild

If Saul had one rule for the sector, it would be this: stop tearing down and start improving what we already have.

“We’ve got to stop demolishing things. The most sustainable building is the one that’s already been built.”

By 2050, around 26 million homes will still be standing. Retrofitting them, making them more energy-efficient, and shifting them to renewable energy should be the priority. Only then, Saul argues, should we focus on new builds — and those should be designed with low-carbon materials from the start.

Beyond Growth

At the heart of Saul’s thinking lies a bigger challenge: our obsession with growth.

“Perpetual growth on a finite planet simply can’t be sustainable.”

He isn’t arguing for decline or scarcity. Instead, he wants to redefine what abundance looks like: homes that are healthy, communities that are safe, and societies that value wellbeing over endless consumption. Leaders, he says, must be willing to measure success not in quarters, but in generations.

Every Degree Matters

Despite the scale of the challenge, Saul refuses to give in to despair.

“Two degrees is bad. Two-point-five is awful. Three is shocking. But 2.9 is better than 3.0. Every tenth of a degree saved preserves possibility.”

That perspective shapes his agenda as incoming CIOB President. His focus is on spreading materials literacy, pushing retrofit-first thinking, and embedding ESG in a way that protects both financial performance and planetary survival.

Closing: A Longer Horizon

When asked what change he would like to see in business, Saul’s answer was quick and clear:

“Encourage all to look for longer-term outcomes.”

He believes the industry must step back from short-term profits and start designing for the generations that will inherit what we build. In a sector built on concrete, it may be the most important foundation of all.

So when UK policymakers failed to define a consistent, credible path to net zero for the built environment, it wasn’t Whitehall that stepped in. It was the engineers.

The result? The UK Net Zero Carbon Buildings Standard: a voluntary, rigorous, and collaborative benchmark for measuring—and more importantly, achieving—net zero in both new builds and retrofits.

Not Just Another Framework

The standard isn’t a white paper or a wishlist. It’s a tool, developed by a coalition of professional bodies—including CIBSE, RIBA, and RICS—and stress-tested by over 200 companies. It defines the ‘what’ and ‘how’ of net zero for real buildings, based on performance, not aspiration.

“This isn’t making it easier for engineers,” Anastasia admits. “But if we’re serious about net zero, this is the way to do it.”

She describes the standard as both “ambitious” and “realistic”—a phrase that only seems contradictory if you’ve grown accustomed to the vagueness of corporate climate commitments. The real success of the standard isn’t just technical. It’s cultural. For once, the fox hasn’t just designed the henhouse—it’s built it out of audited steel, daylight models, and embodied carbon calculations.

From Heat Pumps to Heatwaves: Engineering for the Future

At the core of Anastasia’s work is futureproofing. Her PhD at Cardiff focused on overheating risk in buildings. Her work with UKCIP and Oxford University centred on how climate impacts architecture—not in abstract terms, but in thermal loads, drainage systems, and human comfort.

“I always wanted to be an artist,” she laughs. But architecture taught her that buildings aren’t just objects; they’re organisms.

“It clicked that the building is not just a pretty thing—it’s a living, breathing, dynamic entity.”

That realisation has shaped her entire career, from technical guidance on weather files to overheating methodologies. It’s also why she sees this new standard as a culmination of two decades of work.

Voluntary, Yes. Optional? Not Really.

Why did industry create a voluntary standard when government wouldn’t? Two reasons, Anastasia explains. First: confusion. Competing definitions of net zero made cross-sector collaboration almost impossible.

Second: influence.

“You can’t lobby for policy with ten different versions of what net zero means,” she says.

A single, shared benchmark enables engineers, architects, and clients to finally compare apples with apples.

The irony, of course, is that what began as a workaround now looks like world leadership. “Nowhere else in the world has developed something like this,” Anastasia notes. Already, countries like the UAE and the US are asking how to adapt it.

Cost Is the Elephant in the Plant Room

So why hasn’t the government adopted the standard as policy?

In a word: cost. “There’s an implication that high standards come with high expense,” Anastasia says. But she flips the question: What’s the long-term cost of not adapting? Of relying on imported energy? Of making design decisions that bake in inefficiency for decades?

Her answer isn’t just philosophical. It’s practical:

“Net zero isn’t a five-year thing. It’s the entire lifespan of a building.”

The Magic Wand Moment

When asked what she’d change about the commercial world, Anastasia’s answer is quietly radical:

“I’d like it to be less commercial.”

In a Star Trek-like future where money wasn’t the ultimate measure, she believes we’d rediscover the value of people, nature, and spaces that actually enhance life.

And if that sounds naïve, it’s worth remembering who’s saying it. Anastasia is not an idealist. She’s a professional whose day job involves translating planetary-scale urgency into wiring diagrams, airflows, and load profiles.

The magic, it turns out, isn’t in the wand. It’s in the wiring.

“People still think sustainability is a cost,” she tells The Responsible Edge. “But it’s a strategy for long-term relevance.”

🛋️ Sustainability’s Image Problem

Let’s be honest: in the interiors world, luxury has long been defined by newness. A redesigned kitchen, a showroom-fresh sofa, or a perfectly curated look. As Mirry explains, this traditional mindset often clashes with a planet in crisis.

“Sustainability still gets shrugged off as second-best or second-hand,” she says. “But increasingly, it’s becoming an additional value add—something people are proud of.”

The challenge? Convincing both clients and interior designers that responsible design doesn’t mean compromising on beauty or luxury. That requires education, better data, and most importantly, better storytelling.

🎯 Key Challenges in Sustainable Interiors

Mirry pinpoints five friction points currently hampering progress:

• 📦 Packaging & Waste – Furniture needs serious protection in transit, often creating mountains of non-recyclable waste.

• 🛋️ Big Format, Big Emissions – Think sofas, dining tables, lighting—hard to move, store, or dispose of sustainably.

• 🔥 Sofa Safety Regs – UK fire safety rules make recycling upholstered furniture a nightmare.

• 🧾 Transparency – Designers are often in the dark about supply chains. Brands need to give them better product data.

• 💰 The Perception of Cost – Many still believe sustainability must be more expensive, which simply isn’t true.

“There are huge opportunities for brands that get ahead of this,” she argues. “If you build with transparency, you build loyalty, and that builds long-term commercial value.”

🌱 Meet the Green Room

To help tackle some of these barriers, Mirry co-founded The Green Room with Jules Haines (of Haines Collection). What began as a casual pub chat with a few industry peers has grown into a thriving forum of over 50 interiors brands—big and small—committed to sharing knowledge, cutting corners (ethically), and ditching the industry’s culture of secrecy.

“No question is too stupid in the Green Room,” Mirry jokes. “We get everyone round the table—literally and figuratively—to learn from each other.”

Roundtables, webinars, open-source guides: The Green Room is what the interiors industry desperately needed—somewhere to find inspiration and practical help.

🔮 What’s Next? (And What Keeps Her Going)

At B·ABLE, Mirry works with SMEs across industries, but interiors remains close to her heart. Her goal? Empower teams to act, not just outsource sustainability to one poor soul in the comms department.

“99% of UK companies are SMEs. They don’t have ESG teams. They need simplicity, structure and clarity—and someone to help them communicate it all properly.”

She hopes the long-term legacy of her work will be a generation of brands that don’t just market responsibility—they practice it, collaboratively.

And if she had a magic wand?

“I’d change the perception of sustainability. It’s not a tick box. It’s a growth strategy. It’s your best chance to thrive.”

Kate Chilton, Chief Sustainability Officer and Chief of Staff at BamCore, has experienced both the corporate and startup sides of sustainability. After starting her career at Accenture and working her way into the core of climate startups, she now finds herself in the thick of it—caught between investor expectations, startup survival, and the uncompromising realities of planetary boundaries.

In this episode of The Responsible Edge, Kate takes us on a journey through the messiness of real-world sustainability: the idealism, the disillusionment, and the flickers of optimism that still make the fight worth it.

What Happens When Net Zero Becomes “Too Expensive”?

The catalyst for the conversation is Bloomberg’s recent report on the Net Zero Banking Alliance (NZBA), a group of major banks committed to aligning their lending with the Paris Agreement. One by one—U.S. banks, Canadian banks, and then Japanese banks—have stepped away from the group.

Why? According to Kate, the answer is chillingly simple:

“By exiting NZBA, these banks have sought greater autonomy to set and adjust their environmental strategies without being bound by a commitment to stay aligned to the Paris Agreement—which they now view as a fictitious world.”

Put bluntly: NZBA is aligned with a future that’s becoming increasingly unlikely. And the market will punish banks for focusing on decarbonisation if they are perceived to be giving up earnings potential.

“Sustainability Only Works If It Makes Business Sense”

Having worked at a corporate giant like Accenture and now at a bio-based building materials startup, Kate sees the problem from both ends of the spectrum.

“The sustainable decision needs to be the right business decision. We can’t just expect businesses to do the altruistic thing when they are fundamentally mission-driven to turn a profit.”

Startups may be mission-first, but they’re not immune either. Even companies like BamCore, which manufactures climate-positive building products, must navigate a system where clean energy and low-carbon materials still struggle to compete—on cost, supply, and capital access.

Built-In, Not Bolted-On

Kate wears two hats—Chief Sustainability Officer and Chief of Staff—which gives her a unique view across the entire organisation.

“Sustainability shouldn’t be an afterthought. It needs to be built in, not bolted on.”

This dual role allows her to connect sustainability to every department—from marketing and product development to sourcing and manufacturing. It’s a model that makes sense for startups—but it’s rare in larger organisations, where ESG still too often sits in a silo.

The Capital Gap No One Wants to Talk About

One of the sharpest insights comes when Kate breaks down the climate finance landscape for startups:

• 🥇 Seed-stage: Government grants, angel investors, climate-focused VCs.

• 🏗️ Growth-stage: A funding valley between VC and private equity.

• 🏦 Mature-stage: Shift from equity to debt—often inaccessible for physical solutions that need massive CapEx.

“We’re not playing in electrons—we’re playing in atoms. In order to combat climate change, this is a physical problem. We need physical solutions.”

When capital dries up—particularly for manufacturing-heavy solutions like BamCore—the transition stalls, no matter how compelling the climate case is.

Realism vs. Idealism: Can We Still Be Optimistic?

Kate doesn’t sugar-coat it:

“There’s always a little flame of eco-anxiety driving me. But I’ve moved from being an optimist to an optimistic pessimist.”

And yet, there’s still hope:

• The next generation—Gen Z—is taking climate seriously.

• Clean energy is reaching cost parity with fossil fuels in more regions.

• The appetite for systemic change—from carbon pricing to Doughnut Economics—is growing.

“Our financial system is intertwined with emissions… We need to unwind them such that we can make decisions that are still good for our economies but that also drive down emissions.”

💬 Kate’s Magic Wand Moment

If given a magic wand, what would Kate change?

“Make it easier for companies that want to be sustainable to succeed.”

It’s a simple ask—but behind it lies a radical truth. We know what to do. We just haven’t made doing the right thing easy—or profitable—enough.

Brogan’s journey—from a creative young vegetarian to a senior engineer and environmentalist—reflects a bigger shift taking place across the built environment sector: one that demands we stop settling for “less bad” and start designing systems that actively restore.

From Carbon Focus to Climate Justice

Brogan’s role at Ramboll has expanded far beyond traditional carbon accounting. Today, she leads initiatives around:

• Embodied carbon reduction

• Circular economy and material reuse

• Biodiversity impact management

• Equity and climate justice in design

“We’re still operating in a degenerative paradigm—taking more than we give back. Regenerative design asks: how do we leave places healthier than we found them?”

Her point is clear: net-zero isn’t enough. Construction must actively repair, rewild, and rethink its entire relationship with natural and human systems.

Breaking the “Creative vs Scientific” Myth 🎨🔬

Brogan’s path challenges the old idea that you’re either a creative or a scientist. Initially pigeonholed into the arts at school, it was a single teacher who opened her eyes to the possibilities of blending both worlds.

“Engineering isn’t the opposite of creativity. It is creative—problem-solving with ingenuity.”

This blending of artistry and technical rigour defines her philosophy today, whether redesigning steel systems or reimagining corporate leadership models.

Leading with Softness 💬

Another powerful insight Brogan shared is the shift in how she leads.

“For years, I tried to blend in—to be one of the guys. Now, I lean into softness. Authenticity, empathy, and care are leadership strengths, not weaknesses.”

In a male-dominated engineering world, this shift has helped her build trust and influence far more effectively than traditional command-and-control styles.

Steel, Scrap, and the “Uncomfortable Truth” of Decarbonisation 🔥

Discussing the recent Scunthorpe Steel crisis, Brogan illuminated a critical, often misunderstood issue:

• Scrap steel can only meet a third of global demand.

• Demand for steel is set to rise 50% by 2050.

• Even “low-carbon” solutions like electric arc furnaces aren’t silver bullets unless paired with drastic consumption reduction.

“Specifying recycled steel might look good on a project report. But it doesn’t cut global emissions. We need material reuse, systemic reduction, and real honesty about our limits.”

She also issued a stark warning: without better scrap recovery, smarter material reuse, and demand reduction, the green steel revolution risks being a mirage.

Radical Solutions: Reuse, Bio-Based Materials, and Mindset Shifts 🌱🏗️

Despite the serious challenges, Brogan remains hopeful:

• Steel reuse: Salvaging and recertifying steel from demolition sites could slash emissions dramatically.

• Bio-based materials: Timber, hempcrete, mycelium composites, and more could transform mid-rise construction.

• Innovative concrete technologies: New blends like calcined clay concrete could revolutionise infrastructure if clients embrace innovation and risk.

But the biggest barrier? Mindset.

“Construction moves slowly. It took twenty years to fix basic safety. We can’t afford that pace for the climate transition.”

Graduates and younger professionals, she believes, are key to unlocking faster cultural change.

Brogan’s Magic Wand Moment 🪄

If given a magic wand, Brogan would replace GDP as the dominant measure of success with Doughnut Economics—balancing human needs within planetary boundaries.

“GDP doesn’t equal happiness. We need an economic model that values health, equity, and environmental regeneration.”

Final Takeaway 🚀

Brogan MacDonald’s vision challenges the construction industry—and society more broadly—to stop patching problems and start building net-positive futures. Through material reuse, radical honesty, systemic redesign, and authentic leadership, a regenerative built environment isn’t just possible—it’s urgently necessary.