InsightWhat actually is embodied carbon in buildings?

Embodied carbon, the definition

Embodied carbon is the emissions fooprint that comes from extracting, transporting and manufacturing building materials. Each and every stage of getting building materials to a construction site and into the actual development, causes greenhouse gas (GHG) emissions.

The emissions as a result of materials are…material

We have a reasonable and intuitive understanding of the operating impact that buildings can have on greenhouse emissions yet many don’t stop to think of the impact of creating these buildings in the first place. Embodied carbon accounts for 25% of building sector emissions and up to 11% of all “human caused” emissions globally. It is material and a significant contributor to the greenhouse gas problem.

Now is the time to take action

The 2030 Challenge is an initiative by Edward Mazria and Architecture 2030 to make all new buildings and renovations carbon-neutral by the year 2030 to avoid the catastrophic effects of climate change caused by the building sector. To achieve this, the embodied carbon emissions from all new buildings, infrastructure, and associated materials must be reduced by 65% by 2030, and zero by 2040. 2030 is less than 9 years away and in the cycle of planning and developing major and even lesser construction projects that is literally the equivalent of the blink of an eye.

Understanding the embodied carbon in materials is critical to solving the problem.

Understanding the embodied carbon associated with each material in a project, and thus the embodied carbon footprint associated with the project as a whole is the only way we will ultimately be able to start the process of reducing a project’s impact.

This is currently achieved through a life cycle assessment (LCA) where all phases of a material’s lifespan (extraction, manufacture, transportation, use and disposal) are considered, calculated for a range of environmental impacts. This will normally include CO₂-e emissions (Global Warming Potential, or GWP). The total sum of these carbon dioxide emissions is the embodied carbon value assigned to one unit of that material. We can use LCA data to calculate the total “cradle to gate” or “upfront” embodied carbon impact of materials. This is crucial to enable us to sum all of these up to arrive at a calculation for the carbon emissions impact of the project as a whole.

In years past, accessing all the LCA’s for all of the materials under consideration for a project had been a difficult undertaking. Nowadays though, Environmental Product Disclosures are available from manufacturers. These assessments meet a set of international rules and are usually undertaken by independent parties to verify and publish the LCA’s of the relevant material. Other handy sources of data include LCI databases such as EPiC, from the University of Melbourne.

Technology has been developed to assist design decisions

There are literally thousands of materials available to designers of buildings and each decision made at the design stage will ultimately impact a project’s carbon footprint. Platforms like our own, The GreenBook™, collate, maintain and provide guided access to the embodied carbon data for building materials across the globe. Through our platform, designers can access over 2,500+ datapoints of materials and assemblies, saving you hours of research. These are integrated to visual design guides and performance benchmarks, making it easier for architects and planners to optimise their options and make more informed decisions, at the point of design.