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How smarter engineering designs can help achieve a future without embodied carbon

The decarbonisation agenda: 10 ways to reduce embodied carbon in our built environment

Embodied Carbon

Our built environment is becoming increasingly efficient, and we’ve made tremendous headways to raise awareness and address operational carbon emissions, but the focus is shifting. Without enough attention paid to reducing embodied carbon in our built environment, breakthroughs in climate change mitigation will be almost impossible to realize. 

Growing commitments toward ambitious greenhouse gas reduction goals bolster global momentum toward reaching a net-zero, resilient future. So, where does Embodied Carbon (EC) fit into the picture? We know that embodied carbon emissions in new constructions refer to the carbon dioxide emissions that occur during resource extraction, manufacturing, construction practices, and transport of materials throughout the whole lifecycle of a building or infrastructure project. Essentially, these emissions happen before we even turn on a light switch or crank up the heating in a new building. Be that as it may, operational emissions, not embodied carbon, have underscored climate action in our built environment. But consider this, EC will account for a big chunk of the overall carbon emissions ‘pie’ of new construction by 2050.

Building and construction's share of global CO2 emissions in 2020. (

Global Alliance for Buildings and Construction

Our built environment puts the most pressure on our natural resources and takes center stage in the fight against runaway climate change. 70% of our global energy consumption and carbon dioxide emissions come from cities, even though they only occupy 3% of the Earth’s surface. As if we didn’t have enough to worry about, these emissions are set to double by 2050 [1].

Contractors and developers know addressing greenhouse gas emissions from material extraction and construction is paramount. Yet the question remains whether emissions are being addressed appropriately. In effect, are we gaining ground where we need to be? For years, operational carbon (carbon emissions from a building once it is already in use) has been the main target of emission reduction strategies. But since we expect embodied carbon will contribute over 50% of these total emissions in construction between now and 2050, can we remain on the same course? This statistic reflects a need for structural engineers, architects, and developers to shift focus. They can be major players in embodied carbon mitigation strategies and pioneers in sustainable building design.

Ten ways to accelerate the transition to net-zero

Carbon emissions during a building life cycle (Adapted from 

10% of annual global emissions are linked to the embodied carbon of materials. Regardless of the apparent implications, there is insufficient research on embodied carbon in the building sector. This means that potential initiatives to mitigate the problem will be varied. As we so often do, we’ve thought hard and researched the Top 10 ways to achieve embodied carbon reduction in our built environment and would love to share these with you:


1. Reducing Embodied Carbon through material selection

As you may have already guessed, a building’s overall embodied carbon is linked to the material composition of the products from which it is made. Reducing EC through material selection is a particularly common solution today. It puts maximum power in the hands of architects, engineers, and designers to intervene early in carbon-intensive practices. Following principles of sustainable design and lean construction, designers can minimize the use of high-carbon content materials from as early as the design stage. Depending on the project, designers can reduce the number of carbon-intensive materials (steel, concrete, glass) or introduce carbon-neutral/carbon-positive raw materials. Some carbon-friendly structural materials for use in buildings include:

It goes without saying that designing better would be the most sensible thing. Yet, procurement, economic, technical, and governance barriers that plague the construction industry often put a spanner in the works of good design. Simply put, the industry is worn and stuck in its ways. More intelligent and sound design practices and appropriate choices made at this early stage can be significant factors in embodied emissions mitigation. We know that not all functional designs are necessarily good. So, we want to see more effective and less fragmented decision-making throughout a project using a systematic analysis of all different design stages to assess carbon emissions and design for low-carbon buildings. 

You would also be quite right in thinking that saying ‘design better’ raises more questions than it answers. The frustrating reality is that no solution is perfect and it is the small steps taken toward new means at an early stage that can contribute significantly to the industry’s next big leap. So what are some common, carbon-conscious design choices that engineers can make? 

The lack of design-integrated tools and process guidelines for low-carbon building design at the concept/design stage is setting the industry back. While there are many 

 out there, few inform the early stages of design where some of the most impactful decisions are made. That is a space that CalcTree is keenly watching!

Are you interested in a platform that can smooth out design workflow, avoid project roadblocks and unlock a path to innovative and sustainable design? Sign up with CalcTree today!


Existing and emerging tools and technologies used in the construction sector can benefit from integrating embodied carbon assessments into their workflow.

BIM is a knowledge resource for information in a construction project that allows decisions to be made during the project’s life cycle from conception to demolition.

The Structural Carbon Tool by Elliott Wood and IStructE

 are some examples of Revit or cloud-based tools that allow designers to estimate the embodied carbon of their structure quickly, compare different design options and 

 are all global building rating systems that have so far recognized embodied carbon mitigation as part of minimizing a building’s environmental impact. Building projects aim to gain certification because it means that they have been independently verified as sustainable and have demonstrated environmental stewardship. Holistic rating tools within a comprehensive advocacy agenda can incentivize the race toward net zero. 

Keen to learn more about new tools, methods, and smarter engineering designs? Click 

Big opportunities for embodied carbon reduction and mitigation can lie with the upkeep and renovation of existing buildings and infrastructure. Refurbishment projects can include:

While adding new materials or disassembling old ones can increase the embodied carbon footprint, refurbishments can reduce operational carbon. Research has shown that it is better to bring a building up to modern standards, given that the EC of an average refurbishment project is one-third of that of a new building. 

5. Think circular: preserving embodied carbon through re-use and recycling

There has been a global shift towards circular economy initiatives in the construction sector involving material reuse, recycling, and remanufacturing to reduce waste and preserve the embodied carbon already in the system. Embodied carbon can be held by converting waste, bioproducts, and used materials into building materials. Strides have been made worldwide to implement 

recycled materials into building projects

. Recycled glass, denim, plastic bottles, and reclaimed building materials are reused resources that can have a sizeable impact on embodied carbon preservation. 

6. Embodied carbon mitigation through better construction techniques

Prefabricated and modular construction are emerging as popular design methods in the construction sector. Prefabricated buildings consist of components and elements manufactured in remote factories, transported on-site, and assembled into buildings. Studies have shown that productivity will substantially improve by increasing the proportion of prefabricated elements in a construction project. This will result in faster construction, lower emissions, less waste, noise, disruption, and lower unit and operational costs. A holistic approach combined with other strategies (i.e., using low embodied carbon materials) in on/off-site construction practices can significantly impact EC reduction. 

 in London took prefabricated construction to new heights. It claimed to have reduced embodied carbon by a whopping 40% when compared to traditional construction methods. 

Changing national building codes and standards to address embodied carbon are matters of government policy and industry policy. So is an incentivizing investment in carbon-friendly construction materials and encouraging industry clients to request low embodied carbon materials and outcomes. Implementing and revising policy by governments can have wide-reaching impacts on EC reduction. For example, creating a new or amended design code that includes definitions and guidelines on low/zero carbon materials and systems would drive designers to incorporate or comply with it. Standardizing projects to meet embodied carbon targets would allow designers, contractors, and clients to commit to these initiatives. There are many other government regulations, industry bodies, and stakeholders within construction sectors that can enforce strategies for EC reduction. Whether it be financial incentives, research investment, carbon awareness communication, and targets, these policies will have the most significant reach in tandem with other mitigation strategies. 

Societal changes, perceptions, and awareness are all critical factors in driving action against climate change. The same can be said on a more localized level concerning action towards embodied carbon. Engaging leaders in supply, design, client, and contracting in embodied carbon sessions and summits and providing education about reducing embodied carbon is critical to ensure support for appropriate EC mitigating strategies. This can lead to industry-wide changes and adoptions of low-carbon initiatives and it would generate demand, incentivizing the development of design tools that will evaluate low-carbon design solutions. These tools will evaluate our designs' impacts and create a demand for buildings and projects with sustainable credentials. The global conversation around the necessity of reaching net-zero embodied carbon can spark big leaps in the industry; we just need to adopt a common language, principles, actions, and definitions to yield market action. 

EC assessment falls within a broader discipline called Life Cycle Assessment (LCA). LCA in construction involves an evaluation of environmental impacts during all stages of a building’s life cycle, from material extraction to construction, operation, and beyond. The scope and LCA stages must be defined and known when tracking embodied carbon. The scope of a project, whether it is a large commercial building or a single-story building, has a significant impact on embodied carbon figures. The larger the project’s scale, the more likely it will be responsible for more embodied carbon. Managing embodied carbon within an LCA framework could potentially involve:

The use of local raw materials would benefit local or national economies and drastically reduce transportation emissions, already making up almost a quarter of all CO2 emissions in the construction sector. The majority of transport emissions are produced by transporting construction materials to the site.

Adapted from Australian buildings and infrastructure: Opportunities for cutting embodied carbon

The construction industry accounts for nearly 40% of global energy and GHG emissions [3]. We know that almost half of those emissions will come from Embodied Carbon, yet not enough time, attention, and research has been dedicated to understanding the best ways to mitigate it. It has become clear that operational carbon is just one piece of the carbon footprint puzzle. The next frontier to decarbonize our built environment will be to appropriately address embodied carbon. As you might have noticed, each of the Top 10 ways (listed above) to reduce embodied carbon are inextricably connected, showing us that there is not only a diverse range of approaches to address the problem but that a pluralistic solution must be found since no strategy can effectively stand on its own. 

Since decisions impacting embodied carbon emissions are often during a project’s design stage, this is where CalcTree might be able to help. 

Imagine paying the bill for a product even before you start using it and paying an additional fee after you finish using it. That is the embodied carbon ‘bill’ for new buildings. The ‘carbon emission bill’ starts counting from the manufacture of building materials to construction, it even keeps counting during demolition! Aggregated across all construction projects, the magnitude of this ‘bill’ is astounding, accounting for 11% of the total carbon emission on the planet [1]. 

Since the World Green Building Council proposed the 

 to reach net zero for all infrastructure by 2050, the construction industry is hungry to reduce embodied carbon. Achieving this required cutting down carbon dioxide emissions in the construction process and completing a carbon-friendly life-cycle from production through to the end of life. That is where smart engineering solutions come in, shifting the industry from traditional methods to smarter, simpler, and more environmentally friendly solutions.

Problem identification: Where does embodied carbon come from?

Let’s break down carbon sources from the building life cycle:

Solution brainstorming: What can engineers do to impact embodied carbon?

So now you know what's causing the problem. Let’s pinpoint where engineers can actually have a large impact on emissions.

 Obviously, from the amount of embodied carbon in steel and cement, engineers must look into other options with less of a footprint. Currently, timber is a prominent choice (for mid and low-rise buildings). You can discover more about the timber options in construction in our article 

Sustainability and Timber, Top of Mind and Leading Edge

. Researchers are also already making moves in exploring more exotic materials to replace concrete, such as hempcrete. You can explore more about the magic of hempcrete in another CalcTree article 

 Traditional construction has been racking up the carbon bill for a long time, especially due to construction waste. New machines, new energy sources, better waste management, and new construction methodology, can be brought in to shift the industry to produce less carbon. Modular construction and 

 are some pretty cool examples of this to name a few. 

For structural engineers, the shape of the facade and roof, the thickness of walls and floors, and other structural components all contribute to a building's embodied energy. Hence, optimizing those structures to have them lighter, more slender, and simpler is a prominent option to decrease carbon emissions in construction and save operational energy. One example of such a structure is the slim floor slab structures like 

 Currently, according to the Building Performance Institute report, 35% of buildings in Europe are more than 50 years old, meaning they’re at, or approaching the stage of needing repair, renovation, or demolition. Such structures are likely to release a massive amount of carbon during these processes due to old and carbon-intensive construction methodologies. So it’s critical that modern carbon-friendly buildings are attached with a life-cycle assessment from start to finish. The World Green Building Council already proposes the benchmark to complete the whole life cycle assessment approach for all buildings starting in 2025 [1].

 This is called a ‘Carbon Drawdown building’, which can absorb carbon from the environment during operation and stores more carbon than it emits. How is it possible? The key lies in the use of plant-based construction materials that naturally store carbon throughout their lifetime. A recycled building where its materials and components can be passed down to other infrastructure can also contribute to embodied carbon drawdown. However, this approach goes beyond the current aim of the World Green Building Council and governments.

Solution analysis: How can carbon-reduction solutions be applied for smarter engineering designs?

Let’s deep dive into modern engineering progress in tackling embodied carbon. You can also read about more solutions in our other article on 

Carbon estimation and life cycle assessment: 

The ability to estimate and quantify carbon footprint across the whole lifecycle using life cycle assessment (LCA) helps engineers identify major design problems driving up the carbon footprint and fix them. For example, let’s break down carbon emissions from the life cycle of a door (above picture). So, engineers can consider cutting down carbon emissions in the door from its critical stage, as observed, in its manufacturing or use stages. Solutions proposed could be using 

environmental-friendly materials in manufacturing or reusing the door after disposal.

LCA results for a portion of the building can also be scaled up to provide an overall estimate of the carbon footprint of an entire building. For example, by identifying the embodied carbon in a shallow foundation with poor soil conditions, engineers can optimize the foundation to be deeper with stronger soil on which to position the structure. In conjunction with the LCA metric, engineers can then perform a cost-benefit analysis on each option that considers embodied carbon. This is ideal, however, it’s worth noting that formalizing LCA numbers has been a hard task for a long time due to bureaucracy from international standards and legislative bodies. 

The advancement of modeling techniques such as BIM, and Building Information Technology supports engineers in detailed designs, exact measurements, and cross-disciplinary collaborations. Hence, multiple countries have released environmental product declarations (EPDs) to detail how to calculate the embodied carbon throughout the material’s life cycle. 

Otherwise, many software, design tools, and guidance are available to assist engineers in carbon conscience design methodology. Soon enough, engineers will be able to unify how we estimate carbon and apply it to all existing infrastructure.

Embodied carbon emission in different types of buildings (

Let’s look at the model of a 2000m2 building with 4 stories and 8 units. Increasing the usage of timber materials has the potential to greatly 

. In some cases even results in zero or even negative total emissions! 

Timber has always been a valued material in green constructions. Hence, from foundation to cladding and roofing, there will always be space for use of timber materials. And the right combination of these materials would result in negative carbon emissions, making it far easier to achieve  ‘Carbon Drawdown Building’ status. 

Even though there are limits in strength and maintenance, current technology is enabling the improvements of hybrid timber structures. As such, we’ve never been closer to achieving both high structural and high energy efficiency for tall structures.

The proposed skyscraper C6 at Perth, Australia will be the highest hybrid timber building in the word at 350 m (

Construction method, modular construction: 

To redefine our construction process, modular construction is an advanced method to control the construction environment and limit embodied carbon emissions. Segments or units of the buildings will be constructed and mass-produced in an enclosed environment like a factory. They’re then transported and assembled on site. Construction in an enclosed environment allows for better management of off-site uncertainties like weather, wastage, and time delays, all of which are key factors in embodied carbon reduction. On the other hand, a lack of well-defined construction standards for modular buildings, amongst other things, limits the broad use of this construction method.

📖 The ‘Application of Modular construction in high-rise building’ research paper by Lawson, R.M mentioned that modular construction can reduce landfill waste by at least 70%, delivery vehicle visits by up to 70%, noise and disruption by 30–50%, and reportable accidents by over 80% relative to site-intensive construction.

Solution testing: What a future without embodied carbon looks like?

Unsurprisingly, 97% of the current buildings are not compliant with future carbon reduction targets. This means there’s a long way to go before the ‘Net-Zero’ deadline in 2050.

It’s evident that with current progress, we’re years away from achieving net-zero buildings, let alone carbon-positive buildings. But that shouldn’t stop us from imagining a future where embodied carbon will be eliminated from our structures. Human ingenuity will eventually solve these problems!

The completion of life-cycle assessments will allow all buildings in the world to be designed and built to clear and quantifiable net-zero targets. Hence, better controls over construction conditions will lead to better control over the carbon emission process. The technology candidates could be modular buildings or AI-controlled machines. 

Not only controlled assessment and construction but operational carbon could also be reined throughout the building life cycle. Intelligent buildings with self-sensing, self-maintenance, and self-diagnosis to prevent damage and optimize energy usage during operations. These intelligent buildings will also form the building blocks of future smart cities.

CalcTree is proud to help bring that vision alive as one of the companies aiming to reduce construction and time wasted on the built environment. CalcTree will help integrate tools like LCA and Passivhaus standards in engineers’ design processes. Reducing friction in the application of new and cutting-edge approaches and materials. Join our waitlist today and become one of the first people to experience the new steps toward reducing time and material waste.