What is Embodied Carbon and Why Does it Matter?

Most of us are aware that carbon dioxide (CO₂) emissions are damaging our planet by contributing to global warming and the greenhouse effect, but many of us won’t have heard the term ‘embodied carbon’ before. In this article, we explain what it is and why it is important.

What is embodied carbon?

Embodied carbon refers to the carbon dioxide (CO₂) emissions associated with materials and construction processes throughout the whole lifecycle of a building or infrastructure. This includes any CO₂ created during the manufacture of building materials, transporting building materials and the construction process, as well as during demolition.

Explaining the different elements of embodied carbon

Embodied carbon is often not acknowledged when discussing how ‘green’ or ‘eco-friendly’ a particular building is in terms of carbon emissions, which usually only considers energy use once the building is occupied. However, there are many stages at which emissions can be produced, including those referred to as embodied carbon.

Manufacturing of materials

The emissions associated with the construction of a particular building begin with the materials that are manufactured to create it.

Transporting building materials

Building materials are not often sourced locally and there will be associated emissions involved in the transportation of the materials from the site of production to the location where the building will be constructed.

Construction process

Emissions are also created during the construction process itself, which typically takes many months and requires a great deal of energy use to assemble everything to create the final product.

Building demolition

Once the building is constructed, you might assume that the focus switches from embodied carbon to operational carbon as the building is occupied and used. However, there might come a time when the building no longer serves its purpose or has been bought with the intention of turning it into a new structure. If this happens, you also need to account for the embodied carbon that will be involved in the demolition process!

Why is embodied carbon important?

It is important to acknowledge embodied carbon when discussing the overall carbon emissions of a building or we may get a misleading picture of how ‘green’ certain developments are.

‘Embodied carbon’ is different to ‘operational carbon’, which is a term that can be used to describe the carbon emissions produced by the day-to-day operations of a building, such as lighting, heating, cooling and other energy consumption.

Embodied carbon is expected to account for nearly 50% of the overall carbon footprint of new construction between now and 2050.

For example, concrete is used in the construction of many buildings and a key component of concrete is cement. However, cement is one of the largest emitters of CO2 in the built environment and it is estimated that cement is responsible for 7% of industrial energy use, and is the second industrial emitter of carbon dioxide, with about 7% of global emissions.

If the construction industry continues with ‘business as usual’, estimates suggest that embodied carbon is expected to account for nearly 50% of the overall carbon footprint of new construction between now and 2050. So you can see why it is important that we acknowledge it!

Indeed, some buildings have been described as ‘fossil-fuel free’ because they will run on 100% renewable energy and reach net zero operational carbon. However, this fails to account for the fact that they are constructed from concrete, steel and glass when the production of these materials must involve a large amount of fossil fuels.

The whole supply chain needs to be considered when we talk about the carbon emissions that buildings produce. We need industrial changes in how we produce concrete and other building materials so that we are limiting the production of carbon emissions at every stage of a building’s life, not just when they are operational.