Francis Kéré's Earthen Architecture and the Timber Tower Debate

Sam There's a global competition launching right now that's trying to redefine what "sustainable" even means in architecture — and it's judged on hard data, not on how green a building looks in a rendering. That shift, from aesthetics to metered performance, is going to matter a lot to everything else we discuss.

Maya Okay, so instead of a jury looking at photos and saying "that's a beautiful eco-building," someone's actually checking the meters? Because that sounds like a pretty basic thing to demand, honestly — why has it taken this long for the industry to ask "does it actually work"?

Sam That's exactly the gap this is closing. The Global Alliance for Buildings and Construction, backed by the Turkish COP31 Presidency, has launched the International Sustainable Buildings Competition. It's explicitly performance-based — modeled on something called the World Championship in Energy-Efficient Solutions, which identifies buildings achieving the biggest real reductions in energy consumption using actual metered data, not projections.

Maya So the model they're borrowing already exists — this new competition is applying that same "prove it with your utility bills" logic on a bigger, more global stage. And there's a deadline attached to this, right — this isn't an open-ended thing, applications close at some point and then it culminates somewhere specific?

Sam Right — applications stay open until October 1st, 2026, and the awards get presented at COP31 itself, which is being held in Antalya, Türkiye. So there's a real calendar forcing function here, not just a vague call for entries. And the framing matters: after years of prizes rewarding renderings and rhetoric, legitimacy now runs through verifiable carbon and energy outcomes.

Maya Which is a pretty direct shot at architects who've made sustainability claims that were more aspirational than measured — suddenly you can't just say a building is green, you have to show the numbers backing it up. That feels like it should reshape how firms design from day one, not just how they market afterward.

Sam Exactly, and you can already see that shift playing out in what actually opened this fall. Take Gianforte Hall at Montana State University in Bozeman — a 58,000-square-foot academic building from Lake Flato and Hennebery Eddy Architects, opened September 10th. It's the university's first mass timber building, using regionally sourced glue-laminated timber and cross-laminated timber, or CLT, engineered wood panels layered at right angles for strength.

Maya So instead of steel or concrete framing, the whole structural skeleton is wood — which I assume matters because growing and processing timber releases far less carbon than manufacturing steel or cement. Is that the core sustainability argument for mass timber generally, or is there something specific to this building worth flagging?

Sam That's the core logic — embodied carbon, meaning the emissions baked into materials before a building even opens, drops significantly with timber over steel and concrete. And it's not isolated to Montana. In Ghent, Carmody Groarke completed a five-story mass timber expansion inside a UNESCO-protected historic campus, extending the museum's cultural programming, and its facade uses something called the "Gent Waste Brick."

Maya A brick made out of actual waste — now that's a phrase I need unpacked. What's literally going into it, and does it perform as well as a normal brick, or is this more of a proof-of-concept gesture than something that could scale?

Sam It's lime-cured brick made from municipal trash — crushed concrete, crushed glass — cured rather than fired in a kiln, which is the energy-intensive step for ordinary clay brick. The practice states it produces one-third the carbon emissions of a typical Belgian clay-fired brick. So the emerging playbook for 2026 institutional buildings pairs structural timber to cut embodied carbon with waste-stream masonry to cut the envelope's footprint further still.

Sam Right, so we left off with that competition framework for measuring performance. Let's talk about a building that's actually testing the limits of what timber can do at scale — Atlassian Central in Sydney, which topped out, meaning reached its full height, in late July.

Maya Topped out at thirty-nine storeys, if I remember the height right — and it's being called the tallest hybrid timber tower in the world. But "hybrid" is doing a lot of work there. What's actually holding this thing up?

Sam Three materials working together. Concrete cores — vertical shafts running up the building's center for stability — support mass timber floors and interior structure, and the whole thing is wrapped in a steel exoskeleton, meaning the steel frame sits on the outside rather than buried inside the walls.

Maya So instead of picking one material and building the whole tower out of it, they're using each material for the job it's actually best at — concrete for the core, timber for the floors, steel for the outer skeleton. That's a very different logic from a typical steel-and-concrete skyscraper.

Sam Exactly, and that's the point regulators and other cities are now studying. Concrete production is enormously carbon-intensive — mostly from the chemical process of making cement. Every floor plate you can build from timber instead is carbon you're not emitting, and in many cases, carbon the wood itself is still storing.

Maya So Atlassian Central isn't just a striking building — it's basically a working argument for how far you can push wood before you run into structural limits requiring concrete or steel. A proof-of-concept other engineers can point to.

Sam That's precisely how it's being treated — as the flagship example cited in code debates right now. And those debates are heating up fast, because regulation is starting to catch up to what these engineers have shown is possible. California just gave us the clearest case.

Maya This is the embodied-carbon idea we touched on earlier — the emissions baked into materials before a building is even occupied, as opposed to the energy it uses once people move in. What did California actually change?

Sam Starting this year, California widened the part of its green building code regulating embodied carbon so it now applies to commercial buildings over fifty thousand square feet — a much larger pool of construction than before. Reporting frames California as the first state to regulate embodied carbon directly in its building code.

Maya Fifty thousand square feet isn't a huge building — that's going to catch a lot of ordinary commercial projects, not just flagship towers. So this isn't a niche rule for showcase buildings anymore, it's becoming a baseline expectation for developers.

Sam Right, and that's exactly why the ripple effects matter — reporting describes this as already changing construction practices beyond California's own border, because material suppliers and design firms that work nationally can't easily maintain one carbon standard for California and another everywhere else.

Sam So let's cross the Channel from that timber tower story, because the policy picture around embodied carbon gets genuinely political once you look at the UK. There was a House of Commons debate on July 13th where a member laid out just how big the gap is.

Maya Wait — the gap between what, exactly? I thought we'd already covered embodied carbon rules as part of the timber story.

Sam Right, but that was about specific building codes. This is about the UK's flagship housing policy, called the future homes standard, which regulates energy use in new homes — insulation, heating systems, that sort of thing. The member pointed out it completely ignores embodied carbon, the emissions locked into materials before a building is even occupied.

Maya So the government's big new rule for homes only deals with a slice of the problem — how much energy the house burns once people live in it — but says nothing about the carbon cost of making the bricks, concrete, and steel in the first place?

Sam Exactly that. And the figures cited in the debate make the omission look worse the longer you sit with it — embodied carbon is already around 20% of the UK's total greenhouse gas emissions, and it's projected to become fully half of all built-environment emissions by 2035.

Maya Half, from a category the flagship housing standard doesn't even mention. That's a strange place for policy to be sitting, especially if — as we heard earlier — architects and engineers already treat embodied carbon as the obvious next frontier.

Sam It is, and the debate made a pointed argument about that mismatch: regulators don't need to start from scratch, because the construction industry has already done much of the hard work on measurement standards. The tools to count embodied carbon exist. What's missing is the statutory teeth to require it.

Maya So it's not a knowledge gap, it's a political will gap — the industry knows how to measure this, but nobody's forced to act on the number yet.

Sam That's the shape of it in Britain. The European Union is a step further along, at least on the methodology side. A Council of the European Union document dated March 25th, 2026 lays out how embodied carbon should be counted across the whole continent, and one detail matters a lot: emissions from construction products get allocated to the buildings they end up in, not to the factories that made them.

Maya So if a cement plant produces the material, the carbon debt doesn't sit with the plant — it travels with the product and lands on whichever building gets built out of it?

Sam Precisely, and that's a meaningful design choice, because it means the pressure to decarbonize falls on developers and architects choosing materials, not just on manufacturers cleaning up their factories. The document also sets a fixed reference point: the baseline is the whole-life carbon released from the entire European building stock in the year 2020.

Maya A baseline year gives you something to measure progress against — so any future EU rule can say "compared to 2020, we've cut this much." That makes the policy trackable rather than just aspirational.

Sam That's the intent, and it's framed as a competitiveness argument as much as a climate one — instruments that create demand for low-carbon construction products are described as securing European industry's position and encouraging investment to scale up emerging low-carbon technologies. In other words, regulate the demand side, and the low-carbon materials industry has a reason to grow.

Maya So put the UK and the EU side by side — one is still arguing in Parliament that the rule *should* exist, and the other has already written the accounting method that would let a rule work. That's a real gap in how far along these two are.

Sam It is, and it's worth sitting with, because it undercuts any assumption that sustainable architecture is being pulled forward by government mandate. In both places, the architects and engineers are ahead of the statute books — the profession has largely agreed embodied carbon is the next frontier, but enforcement is fragmented, contested, and in the UK's case, still just a debate on the record rather than a rule on the books.

Sam So let's turn to Francis Kéré, who won the Pritzker Prize back in 2022 and has stayed the most-cited name this season for building with earth. His newest project, the Goethe-Institut cultural center in Dakar, officially opened on April 18th of this year.

Maya Dakar — that's Senegal, right on the coast. What's the site like, and how did that shape what he built there?

Sam There was already a huge baobab tree at the center of the plot, surrounded by other big trees. Kéré has said he approached the site as a place that already had its own structure — formed by the trees, the shade, and the logic of the land itself, before he'd designed a single wall.

Maya So the landscape basically handed him the floor plan. That's a nice inversion of how we usually think about architects — imposing a design on a blank lot rather than reading what's already there.

Sam Exactly that inversion, and it connects to something bigger he said at the opening. He tied the design directly to resource scarcity, saying, quote, "if you give me sand, mud, and bamboo, I can guarantee you I will create a project for you." That's not a slogan — it's a working method he's built a whole career on.

Maya And earthen building, just to be clear for anyone who hasn't followed this — that means using compressed earth, mud brick, that kind of thing, instead of steel and cement, because it needs almost no industrial processing and no long supply chain?

Sam Right, and Kéré went further at the inauguration and linked it to actual geopolitics. He referenced the energy crisis from the closure of the Strait of Hormuz and argued that region has alternatives — rethinking how cities are built and cutting energy use — and said a well-executed earthen building can contribute significantly to that.

Maya That's a bold claim to make about a cultural center — that a building material choice connects all the way up to a global energy chokepoint. But it does make the stakes concrete: this isn't just aesthetic, it's about not depending on imported fuel and imported materials.

Sam Which is exactly why the next piece of his work matters so much for this episode. He's also designing the new National Assembly building for Benin, a much bigger, more structurally demanding project, and there he's been candid that earth alone can't do it all.

Maya What does he actually say about that? Because it would undercut everything if he just quietly switched to concrete and never mentioned it.

Sam He doesn't hide it at all. His line is, "when a massive project cannot use earthen bricks throughout... we will use concrete the way that is efficient." So he's not treating earth as an ideology he must defend at all costs — he's treating it as one tool among several, chosen where it actually performs.

Maya So restating that: the message isn't "natural materials always, concrete never." It's "match the material to what the building actually needs to do, and don't waste resources pretending a legislative chamber can be built the same way as a village school." That's a much more useful lesson than the purist version.

Sam That's precisely the point, and it's reinforced again by his most unlikely commission — the forthcoming Museum of Art in downtown Las Vegas. Kéré himself has said this project has thrust him into, quote, "a completely other world," which makes sense — Las Vegas is about as far from Gando as an architectural context gets.

Maya Gando being his home village in Burkina Faso, where he built his very first school out of local earth. So now he's designing for a desert casino city instead of a farming community — does the philosophy survive the jump?

Sam It does, and that's the anchor for this whole segment. Even in Las Vegas, his firm says the museum will still use locally available resources — specifically native red rock from the surrounding desert. So the constant across Gando, Dakar, Benin, and Las Vegas isn't one material, it's a method: read what the specific place already offers, then build with that first.

Maya Which actually complicates the neat story a lot of people want to tell — "traditional earth architecture good, industrial concrete bad." Kéré's own body of work argues against treating it that simply.

Sam Right, and that tension — vernacular material logic meeting large-scale, high-performance need — is going to come back when we get to the timber tower conversation later, because it's the same underlying question: what's the right material for the job the building actually has to do.

Sam So let's shift to something more like a pulse check on the industry rather than one architect's story — the World Architecture Festival's 2026 shortlist, which came out in July. It's worth thinking of this as a barometer of where the profession's attention is going, even before we know who actually wins.

Maya A barometer meaning it tells you what people are submitting and prioritizing, even if the verdict on quality or winners isn't in yet? So it's more about volume and category emphasis than results.

Sam Exactly right. And the volume here is notable — the programme director flagged more than 630 entries to the awards programme this year, which he pointed out came despite real headwinds in the construction sector globally. That's a sign sustainability-minded design work is still being produced and submitted at scale, even when the broader industry is under financial pressure.

Maya That is genuinely reassuring, actually — you'd think a squeeze on construction budgets would mean fewer ambitious, sustainability-forward projects, since those often cost more upfront to plan properly. So the fact submissions held up suggests architects are still pushing this agenda even when money's tight.

Sam That's the implication, yes. The festival itself spans 43 categories, and this year it's staging its climate-specific honors — the WAFX Awards, which single out architecture addressing major world issues including climate — separately and earlier, on July 20, with Special Prizes following on July 27. The main festival and grand prizes come later, so we genuinely don't know the winners yet.

Maya So this is a bit of a cliffhanger for us — we can tell you what's being recognized as important, but not who's actually taking the top prize. That feels like something worth circling back to once those results land.

Sam Definitely a developing story, and one we should revisit. But there are two other dated events bookending this same period that tell a similar story about where award culture is heading. One is a revamped Architecture MasterPrize ceremony, happening at The Peninsula London on September 30, 2026, which is introducing eight new categories — covering climate resilience, digital sustainability, and sustainable cities.

Maya Eight new categories just for sustainability-adjacent themes feels like more than a tweak — that sounds like an organization rebuilding its whole taxonomy around climate rather than treating it as one box among many alongside things like "best interior" or "best residential."

Sam That's precisely the signal. It suggests award bodies are recognizing that climate resilience and resource constraints aren't a side conversation anymore — they're becoming the organizing logic for how architecture gets judged at all. The other event worth naming is happening in Paris: RCR Arquitectes, the 2017 Pritzker laureates, working with CALQ Architecture, are completing a redevelopment of the former Renault factory site on Île Seguin in Boulogne-Billancourt, opening October 17.

Maya A former car factory — so this is industrial land getting a second life rather than being demolished and rebuilt from scratch. Is that the same "dwindling resources" logic we've been talking about with timber and earthen construction, just applied to an entire site instead of a single building material?

Sam Exactly the same logic, just at a different scale. Reusing an existing industrial footprint means you're not consuming new land, and you're not paying the carbon cost of demolishing and rebuilding a structure's foundations and infrastructure from nothing. It's brownfield reuse — redeveloping previously built, often contaminated or obsolete industrial land — and it runs in parallel to the new-build timber story we covered earlier, as another core strategy for building within limits rather than around them.

Sam So let's end where the reporting itself ends — with questions nobody's answered yet. The first is about who should even be setting these embodied-carbon rules. California's moving on its own, state-level, while the EU and UK are still drafting harmonized frameworks. Do you let one state run ahead, or wait for everyone to move together?

Maya That feels like a real trade-off, not just a technicality. If California sets its own rule now, builders there get moving sooner — but if it doesn't match what the EU eventually lands on, you've got companies designing to two different rulebooks. Is that the actual tension, or is there more to it?

Sam That's exactly it, and current coverage doesn't resolve it — it's flagged as genuinely open. The second tension is sharper: is something like Atlassian Central real decarbonization, or is it "timber-washing" — using visible wood to market a tower that's still mostly steel and concrete underneath?

Maya Timber-washing — so the worry is a building gets called sustainable because you can see the wood, even though the actual carbon math might not be that different from a conventional tower. That's a real accusation to level at a landmark project. Does the reporting take a side on that at all?

Sam No, and that's the honest answer — it's raised as a live question rather than settled either way. The same goes for the COP31 competition we mentioned earlier: will judging on measured performance before the October 1, 2026 deadline actually change what gets built, or will it just hand a prize to buildings that were already funded and underway?

Maya So the risk is the competition ends up celebrating business-as-usual dressed up as innovation, rather than actually pulling forward projects that wouldn't have happened otherwise. That's a fair thing to sit with unresolved — I'd rather you tell me it's contested than pretend there's a tidy answer.

Sam Agreed, and that's really the throughline for the whole episode — Kéré's earthen buildings in Gando and Dakar, the timber towers, the carbon rules, all of it sits inside industry-wide arguments about what "sustainable" even means, measured against a world with fewer resources to spare and less time to get the definition right.

Maya Bringing it back to Kéré feels right, since he's who we started with. His work makes the case that sustainability isn't one fixed technique — it's judgment, shaped by where you build and who you're building for. These open debates are basically the field still arguing that same question, just at a bigger scale.

Sam Exactly right, and that's a good place to leave it. We went from Kéré's earthen buildings, shaped by his own childhood in Gando, through the timber tower milestone in Sydney and the embodied-carbon rules now being fought over in California, the UK, and the EU, to the 2026 Pritzker and World Architecture Festival shortlist — and now these open questions about whether any of it adds up to real change or just better marketing.

Maya It's been a genuinely useful map of where sustainable architecture actually stands right now — not settled, but moving, and worth watching closely as these debates play out.

Sam Before we go — this show is AI-generated, the voices you're hearing are synthetic, and everything we've covered comes from source documents whose authors have no affiliation with this show. Everything today came from: the news hook about a global competition to define what "sustainable" now means, judged on data, not intentions; a piece on buildings actually opening this autumn, the mass-timber and waste-material wave; coverage of the timber high-rise frontier, with Atlassian Central topping out in Sydney; reporting on regulation catching up, as embodied carbon becomes a live legislative fight; a piece on the 2026 Pritzker Prize as an argument about permanence itself; profiles of Francis Kéré, from Gando to Dakar, Benin, and Las Vegas; and of Marina Tabassum, on climate-vulnerable geography as design method; coverage of the Global Award for Sustainable Architecture 2026 in Istanbul this April, the "who's next" bench; a piece on World Architecture Festival 2026 as a barometer of volume and priorities, with its verdict still pending; a rundown of what's landing right at the edge of the window, just ahead; and finally, the piece laying out contested points and open questions for the episode.

Maya Thanks so much for listening, everyone — take care, and we'll see you next time for more on the buildings shaping how we live with fewer resources and far less room for error.