The building and construction industry is a sector that is heavily tied to natural resources and contributes to a large discharge of greenhouse gas emissions. Therefore, reducing carbon emissions is the key to decreasing the built environment’s impact on climate change.
The race to achieve net-zero buildings has already started. But without a focus on addressing both embodied and operational carbon in the building industry, we will not achieve the hoped-for mitigation of climate change. Environmentally friendly building materials represent a viable solution, but to achieve long-term benefits the whole lifecycle of a building must be taken into consideration.
What is embodied carbon in buildings?
Embodied carbon in buildings refers to the carbon dioxide (CO₂) emissions during the construction of a building. It includes the emissions created during the extraction of raw materials, the manufacturing and refinement of building materials, transportation to the construction site, and disposal of old supplies. In simple words, embodied carbon refers to the emissions of a building before it becomes operational.
Why tackle embodied carbon emissions?
To become carbon neutral and deliver net zero buildings, developers and contractors need to focus and invest in reducing embodied carbon emissions. This should become a priority for many reasons: specific limits on embodied carbon will be mandated, using fewer resources can reduce costs and risk around resource availability, and it may be a requirement to obtain planning permission in the future.
How to tackle embodied carbon? There are some changes we can make, such as reusing existing buildings, substituting low-carbon materials e.g. concrete mixes, choosing less carbon-intensive materials, using natural materials and repurposing materials.
What is operational carbon in buildings?
Operational carbon in buildings refers to the amount of CO2 emissions produced once a building is in use - from the energy and ventilation systems, to the IT equipment. Operational carbon is easier to quantify than embodied carbon and has been a reduction priority for a while now. In order to reduce operational carbon in buildings, the aim is to understand which areas are most energy intensive through smart metering and to implement strategies to reduce consumption.
Embodied and operational carbon working together
Until recently, embodied energy was assumed to be proportionally insignificant when set against the operational part of the life cycle energy. Consequently, reducing operational carbon emissions was considered to be more important than reducing the embodied emissions.
Operational and embodied phases, amounting to 80-90% and 10-20%, respectively, are the main contributors to the building’s lifecycle energy demand. However, based upon the type and the function of a building, along with other factors including geographic and climatic conditions, the building’s orientation and structural system, the building’s lifespan, etc. embodied carbon can become proportionally higher. Typically embodied carbon accounts for less than 20% for conventional buildings but can reach up to 80% of lifetime carbon emissions for low-energy buildings and almost 100% for zero-energy buildings.
Make a difference
Building professionals have a responsibility to optimise their processes in favour of decarbonisation. Whatever your role in the building process, a sustainable approach to your project can make a huge difference in the long run, and benefit your business, customers, and the planet.