The Carbon Mirage: Are We Really Building Green?
We’ve all seen it. The smug satisfaction of an electric car owner gliding silently through the streets, believing they’ve ticked the “planet-saving” box. But here’s the uncomfortable truth: while the car emits zero tailpipe emissions, the carbon cost of mining, manufacturing, shipping, and ultimately recycling that vehicle has just been offshored and frontloaded into the supply chain. The damage is already done—long before the first journey to the supermarket.
It’s a classic case of “upstream carbon debt”: we feel greener because the emissions aren’t visible in our daily lives, but the earth’s atmosphere doesn’t care where or when the CO₂ was released.
This same illusion plagues construction.
New Builds vs Old Buildings: The Real Carbon Trade-Off
When we demolish a century-old terrace to erect a “sustainable” new build, are we really cutting carbon? Or are we just pulling the same EV trick—pushing emissions upstream to the brickworks, concrete plants, and transport fleets that feed our industry?
Every new home comes with a “carbon price tag”:
Embodied carbon in materials like steel and concrete
Energy spent in transport and assembly
Carbon lost in tearing down an existing structure
Compare that with repairing, retrofitting, or extending an older building. Cob walls, timber frames, and stonework might not win awards for airtightness, but they carry centuries of locked-in carbon—and avoiding demolition prevents a fresh spike of emissions.
The Case for Cob and Carbon-Savvy Materials
Materials like cob, rammed earth, and straw bale aren’t just nostalgic curiosities. They’re low-embodied carbon heroes:
Minimal processing
Local sourcing
End-of-life recyclability
Yet they’re often overlooked in favour of highly processed “eco-products” with impressive brochures but questionable cradle-to-grave impacts.
If we’re serious about reducing carbon, we need to stop obsessing over a building’s operational energy alone and start accounting for its lifecycle carbon—from extraction to end-of-life.
So, What’s the Answer?
There’s no silver bullet. But as an industry (and as homeowners), we need to:
Prioritise repair and retrofit where possible
Challenge embodied carbon in every material choice
Value traditional, local materials for their ecological sense
Recognise that sometimes the “greenest” building is the one that’s already standing
Because real sustainability isn’t about feeling good in the showroom or on the spec sheet. It’s about making choices that reduce harm across generations—not just shifting it out of sight.
