How low can we go? To cut the carbon that goes into buildings to net zero, we need radical change
Embodied carbon remains unregulated
One of the biggest challenges is that embodied carbon is entirely unregulated, except in five countries – Denmark, Finland, France, the Netherlands and Sweden – that have brought in minimum standards. In most other places, it can effectively be as high as you like.
This is a problem, because the materials we use to build have enormous environmental impacts. Cement production is responsible for 8% of all greenhouse gas emissions and steel another 7%. Aluminium, copper, glass, bricks and more all add significantly to global emissions.
In response, the World Green Building Council has set targets to reduce embodied carbon by 40% by 2030, and to net zero by 2050. But there is little consensus about how this can be achieved, or even if it’s possible.
How low can we go?
Our study explores the extent to which we can reduce embodied carbon in Australian office buildings.
We took a “best practice” office building with a hybrid structure of timber and concrete, and redesigned it with a standard concrete frame to reflect a more conventional building. We then measured their upfront embodied carbon – the carbon needed to construct each building in the first place. The best-practice example had 14% less embodied carbon than the conventional building – good, but some way off our 2030 aspirations.
So, we redesigned the building again. We made the structure entirely timber and added columns to remove the need for beams. This might seem like a minor change, but more columns would require a shift away from the “open plan” offices that have become the norm.
We also used straw insulation in the walls, reduced glazing and unnecessary finishes, and increased reused and recycled materials throughout. By the end we had cut the upfront embodied carbon by 45%, from 520 kilograms of CO₂ equivalent per square metre to 287kg. But many of the moves we made are far more radical than common industry practice.
