Embodied Carbon: How the Building Industry Can Make Meaningful Reductions

by Eddie Rayner September 20, 2022

Samar Hussein from Gensler Middle East discusses key findings from the recent report by Gensler Research Institute on Quantifying Embodied Carbon.

For decades the building industry has been focusing sustainability efforts on optimizing building performance, often leading to valuable reductions in buildings energy consumption and operational carbon emissions. This impact, though valuable, only addresses one part of the equation needed to achieve carbon neutrality in the building industry.

We need to prioritize both operational and embodied carbon in design and construction to actively reduce carbon emissions associated with the built environment. Currently, embodied carbon constitutes approximately 30% of building-related emissions. It is estimated that embodied carbon will be of equal to, or greater impact than, operational carbon as building energy sources shift away from fossil fuels and building systems become more efficient. With global population growth, real estate developments are expected to double by 2060. To put that into perspective, it would be equivalent to constructing a new Dubai every 2.3 days or a new Paris every week. The result of projected developments will be massive material extraction and utilization, and may lead to a bigger strain on global natural resources unless we reduce our conventional building practice emissions.

According to the UN Environment Global Status Report 2017; EIA International Energy Outlook 2017, projected total carbon emissions based on estimated emissions of global new construction from 2020–2050 were 51% operational carbon and 49% embodied carbon.

Buildings account for 39% of global, energy-related, carbon dioxide emissions in constructing and operating buildings. Current building codes address operational energy but do not directly address carbon or account for emissions related to the manufacturing of materials or construction.

Gensler’s research team set out to understand how best to appropriately measure embodied carbon, and to identify the greatest sources of it in its own portfolio. Following the data collected, it was then analyzed and examined to generate a response to the question: What are the most effective actions to make reductions?

Embodied carbon refers to the carbon emissions arising from the extraction, manufacturing, transportation, installation, maintenance and disposal of building materials

Factoring building products associated with the building lifecycle and taking into account factors such as longevity, maintenance and replacement, it became clear that while base building materials represent the most carbon impact up front, interior materials can have the greatest impact over a project’s full life cycle when cyclical renovations are considered.

The research identified structural steel, plate steel and structural concrete to be the most carbon-intensive products for base building materials. For interior materials, the carbon impacts are more evenly spread within the top ten most carbon-intensive products, with workstation desks and demountable system framing being the most carbon-heavy interiors products. This was conducted by measuring average A1-A3 carbon intensity data by material category across case studies.

The research identified structural steel, plate steel and structural concrete to be the most carbon-intensive products for base building materials

The research identified four ways to prioritize changing the way we design to achieve our goals:

Provide designers with guidance to prioritize materials that have low embodied carbon in materials they specify, such as façade system components and carpets.
Promote data advocacy by having materials libraries to ensure manufacturers for EPDs disclose Global Warming Potential (GWP) for materials where there isn’t enough market transparency.
Ask contractors to provide environmental product declarations and write transparency and performance values into green specifications for materials they specify, for example, non-structural steel, board insulation and blanket insulation.
Engage structural engineers early in the concept design and provide structural guidance to facilitate collaboration on low-carbon designs and to consider alternatives to carbon-intensive steel and concrete.

The research has shown the necessity of understanding how to measure our true embodied carbon footprint, promoting the disclosure of materials data surrounding carbon emissions, and empowering our designers to make an informed decision on the materials we use in our projects.