Architects play a key role in reducing the impact of buildings on the environment. One of the most important areas to focus on is embodied carbon—the carbon released during the creation, transport, and disposal of building materials. By understanding and designing to reduce embodied carbon, architects can help make buildings more sustainable and meet national carbon net zero targets.
Buildings are responsible for nearly half of the greenhouse gas emissions in the UK. They produce carbon in two main ways:
1. Operational carbon – the energy used during a building’s daily life, such as heating, cooling, lighting, and appliances.
2. Embodied carbon – the emissions from producing building materials, transporting them to the site, installing them, and disposing of them at the end of the building’s life.
Both types of carbon are important, but they require different strategies to reduce. Architects and designers have a central role in reducing the carbon footprint of buildings, and focusing on them early in the design process can make a huge difference.
Operational Carbon: Managing Energy Use
Achieving operational carbon net zero means designing a building that uses very little energy and can meet its energy needs from renewable sources. Tools and methods like the Passivhaus standards are widely used to measure energy use and improve efficiency. For retrofitting older buildings, similar strategies can reduce energy use and cut emissions.
While operational carbon is easier to measure and predict, embodied carbon is more complex and often overlooked—but equally important.
Understanding Embodied Carbon
Embodied carbon is the total carbon emitted during the entire life cycle of building materials. This includes:
- The extraction and manufacturing of materials
- Transport to the construction site
- Installation and construction work
- Maintenance, repair, and eventual disposal or recycling
Designing buildings with low embodied carbon is challenging, because tools for measuring it are still developing. But architects can follow structured approaches to reduce it. One such approach comes from LETI, a network of over 1,000 professionals working to make London’s buildings zero carbon. They propose six practical actions to design carbon out of buildings.
Six Actions to Reduce Embodied Carbon
1. Build Less
The first step is to question whether every part of the project is necessary. Can an existing building be adapted instead of creating a new one? Can spaces be shared or used for multiple purposes? Can the design be simpler without losing function?
At Marlborough Sports Garden, Cullinan Studio applied this principle by designing a small, efficient building with multifunctional spaces. They reused materials, like reclaiming a brick wall to create a foundation, reducing both waste and carbon emissions.
2. Build Light
Reducing the weight of a building reduces the amount of materials—and carbon—needed. Architects can limit heavy materials like steel and concrete and reduce foundation sizes.
For Marlborough Sports Garden, a timber frame was used to minimize the building’s weight. This reduced the need for heavier materials, lowering the project’s overall embodied carbon.
3. Build Wise
Designing wisely means planning for material efficiency and longevity. Architects should focus on using materials that last, and design with standard sizes or repeating modules to minimize waste.
Reclaimed hardwood timber was used in Marlborough Sports Garden. By designing around standard grid modules, reclaimed materials fit well without excessive cutting or waste, reducing carbon impact.
4. Build Low Carbon
Some parts of a building, like the structure and envelope, carry more carbon than others—these are called “big ticket” items. Focusing on low-carbon options for these items makes the biggest difference. Architects should prioritize recycled, reused, bio-based, or responsibly sourced materials.
Marlborough Sports Garden used reclaimed steel, gas pipes, sheet metal, and timber. Choosing these materials significantly lowered the building’s embodied carbon.
5. Build for the Future
Buildings should be flexible, durable, and easy to adapt as needs change. They should also be designed to allow materials to be reused or recycled at the end of their life. Mechanical fixings instead of adhesives, for example, make it easier to dismantle materials without damage.
The construction at Marlborough Sports Garden was designed to be deconstructed in the future, ensuring that materials could be reused or recycled.
6. Build Collaboratively
Reducing carbon is not just a design task—it requires teamwork. Architects should consult with clients, communities, and other professionals. Sharing knowledge, ideas, and data ensures the best solutions are found to minimize carbon.
Cullinan Studio worked closely with the local community and stakeholders at Marlborough Sports Garden. Extensive surveys and forums helped guide the design to meet user needs while minimizing environmental impact.
Measuring Embodied Carbon
One of the biggest challenges is building carbon analysis. To make informed choices, architects need to estimate the carbon impact of different materials and design options. This involves multiplying the quantity of each material by its carbon factor—a number representing carbon emissions at every stage of the material’s life.
While this may sound complex, tools and databases are available to help architects calculate carbon early in the design process. This allows informed decisions that reduce embodied carbon from the start, rather than making compromises later.
Whole Life Carbon: Combining Embodied and Operational
True sustainability requires looking at whole life carbon, which combines both operational and embodied carbon. According to LETI, whole life carbon is “the total greenhouse gas emissions and removals associated with a building over its full life cycle, including disposal.”
Using tools like the FCBS CARBON tool, architects can estimate whole life carbon to make buildings that are functional, beautiful, and net zero in carbon. Achieving this requires not only accurate building carbon analysis, but creativity, innovation, and collaboration across the design team.
Conclusion
Reducing carbon in buildings is a critical step in fighting climate change. By focusing on both operational and embodied carbon, architects can design buildings that are energy-efficient, long-lasting, and environmentally responsible. Applying practical strategies like building less, building light, and building low carbon, combined with careful building carbon analysis, helps create sustainable buildings that benefit people and the planet.
The example of Marlborough Sports Garden shows how these principles can be applied in real projects—proving that low-carbon buildings are practical, inspiring, and achievable.
