Embodied Energy in Building Materials: What it is and How to Calculate It

Every human activity has an impact on the environment. Some have a smaller impact, while others are more significant. According to UN Environment Program (UNEP), 30% of all greenhouse gas emission comes from the construction industry. The release of gases like CO2, O3, halocarbons and water vapor can be caused by activities such as mining, processing and transportation. These gases absorb some of the sun’s radiation and redistribute it in the atmosphere. This causes our planet to warm. This layer becomes thicker as a result of the increased amount of gas being released into the atmosphere each day. This allows solar radiation to enter the planet and stay there. This ‘layer’ is so thick that humanity is now experiencing severe consequences such as desertification and ice melting. It also causes water scarcity and intensification of hurricanes, storms, floods, which can alter ecosystems and reduce biodiversity.

One of the most important concerns architects should have is reducing carbon emissions from buildings they construct. This quality can be measured, quantified, and rated.

CopenHill Energy Plant and Urban Recreation Center / BIG

The termEmbodied EnergyOrEmbodied CarbonThis is the total impact of all greenhouse gases emitted by a material over its entire life cycle. This includes extraction, manufacturing, construction and maintenance. Reinforced concrete, for example, is a material that has very high embodied energies. Large amounts of carbon dioxide are released during cement manufacturing. This is where limestone is converted into calcium oxide (quicklime) and also when fossil fuels are burned in furnaces. These issues are not only related to the extraction of sand and stones, but also the transport of the cement to the site. This allows us to understand the environmental impact of every project decision. Ceramic, brick, and other construction materials require large amounts of energy in order to manufacture. The minerals that make them must also be extracted and processed in high-energy processes.

Cortesia de ArchDaily

It is important to remember that there are two types carbon emissions related to buildings: Operational Carbon and Embodied Carbon. This refers to all carbon dioxide that is emitted over the entire life of a building’s materials and not just electricity consumption.

CopenHill Energy Plant and Urban Recreation Center / BIG. Image © Rasmus Hjortshoj

It is crucial to understand the energy and carbon content of building materials in order to create more environmentally-friendly projects. Due to the availability of local resources and the type or transport involved, a’sustainable material” may be high in energy in one location but not in another.

The Life Cycle Assessment (LCA) is a standard method for quantifying the environmental impacts of buildings. It covers the entire life cycle of the building, including the extraction and manufacture of materials, as well as the disposal of the products. The Life Cycle Assessment (LCA) uses a quantitative approach to calculate numerical results that show the impact categories and allow for comparisons between products. The University of Bath (UK) has created a list that compares the energy content of the most widely used materials in the world.

Nest We Grow / UC Berkeley + Kengo Kuma & Associates. Image © Shinkenchiku-sha

Other tools and technologies are available that can help facilitate the process. Autodesk has created the Embedded Carbon in Construction Calculator, in collaboration with the Carbon Leadership Forum, and other construction and software companies. This tool is now available to all beta users. It is designed to give users the information they need in order to make better decisions about the embodied CO2 of each building element. This tool promotes intelligent, conscious and accessible solutions, even for non-specialists. Awareness in making decisions and being aware of all options are the best ways to make processes more intelligent, sustainable and sustainable.