Efficient Material Use by Homebuilders Could Cut Emissions by 52 Billion Tonnes

In a first-ever study, an international team of industrial ecologists has determined that reducing material use in building construction could lower production emissions by 22 to 61% by 2050.

In the study, published in the journal Nature Communications, the researchers explain that material efficiency (ME) can be achieved through things like design change (smaller houses) and material substitution (using wood instead of concrete). The more builders focus on these strategies, they write, the less societies will have to rely on carbon capture and other “negative emission” technologies.

Currently, industrial production of the materials that go into finished products like cars and buildings accounts for 23% of annual global greenhouse gas emissions. That has policy-makers waking up to the need for strategies that prioritize resource efficiency and the so-called circular economy.

But while the benefits of these initiatives seem clear, “detailed assessments of their GHG reduction potential is lacking,” say the study authors.

Determined to address this gap, University of Freiburg researcher Stefan Pauliuk and his team modelled global material efficiency for passenger vehicles and residential buildings, estimating “future changes in material flows and energy use due to increased yields, light design, material substitution, extended service life, and increased service efficiency, reuse, and recycling.”

The scientists found that, depending on policy assumptions, a shift in strategies can result in cumulative global reductions of 20 to 52 gigatonnes (Gt) of CO2 equivalent for residential buildings and 13 to 26 Gt for passenger vehicles by 2050.

“Next to energy efficiency and low-carbon energy supply, material efficiency is the third pillar of deep decarbonization for these sectors,” the authors write.

And it will be a critical pillar, too. “Decarbonization of industry and material production, in particular, requires technological and organizational change and large investments into new energy infrastructure and factories,” explain the authors. But the road will not be easy: “The median remaining lifetime of existing production facilities for cement and steel stretches to 2045, causing substantial lock-ins that impede decarbonization efforts in this sector.”

Moreover, any strategy to decarbonize—rather than reduce—materials will require new technologies and would “compete with other applications of low-carbon energy, including electric transportation and low-temperature heat”. With that in mind, the authors conclude, it is far better to use different and fewer materials in the best possible way.

“Lifting ME to similar prominence as energy efficiency increases the feasibility of attaining the Paris goal of limiting global warming to well below 2°C and may reduce the dependency on negative emission technologies,” they write. “ME shows strong co-benefits in savings of raw materials, energy, and GHG emissions, and its technical and scaling feasibility is high.”