Tools and Solutions to Reduce the Embodied Carbon of Constructions

Operational Carbon and Embodied Carbon

The construction sector is one of the largest consumers of resources globally, contributing over 30% of total energy-related emissions. But what makes this sector so impactful?
When discussing emissions, it is crucial to differentiate between operational carbon and embodied carbon in buildings.
The first relates to emissions from energy consumption needed to operate a building throughout its life (electricity, heating, cooling). It can be reduced through energy efficiency measures or increased use of renewable energy.
On the other hand, the second refers to the total greenhouse gas emissions attributed to construction materials over their entire lifecycle, from raw material extraction to production, construction, maintenance, and disposal. Embodied carbon is an integral component of buildings, making it challenging to mitigate after construction.
The true challenge in reducing emissions lies in reducing embodied carbon and unlocking innovation opportunities.

Methodologies for Estimating Environmental Impacts

What are the strategies and solutions available?
A first step is adopting life cycle assessment (LCA), a crucial analytical methodology that calculates emissions and other ecological impacts associated with construction materials and processes, providing concrete figures for comparing similar materials.
A specific and widely used methodology for LCA is the CML (developed by the Centre of Environmental Science at Leiden University), which defines standard indicators for evaluating various environmental impacts. Other well-known methodologies include TRACI (Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts) developed in the U.S. and ReCiPe, a European methodology integrating impacts throughout the lifecycle. LCA thus becomes a key tool for guiding design decisions and material selection.

Digital Tools for Environmental Impact Assessment in the Construction Sector

Digital tools and software such as Tally, OneClick LCA, EC3, and Athena facilitate these analyses, helping designers, architects, engineers, and other professionals assess the environmental impact of construction materials and processes. These tools make choosing sustainable alternatives and making informed design decisions easier.

Innovative Solutions in the Cement Industry

Another critical area for emission reduction is the cement industry, which releases approximately 2.8 billion tons of CO2 annually.
In recent years, innovative solutions have emerged to help control emissions in this sector.

Self-Healing Concrete

A promising example comes from the Worcester Polytechnic Institute (WPI) in Massachusetts, where a research team has developed self-healing concrete. This technology uses CO2 to repair structural cracks, reducing the need for extensive repairs and extending the lifespan of structures.
The key to this concrete is an enzyme called carbonic anhydrase, found in human red blood cells. When applied to concrete, carbonic anhydrase accelerates the reaction between ambient CO2 and cementitious material, naturally creating compounds that seal small cracks.

Green Low-Carbon Cement

For key materials like cement, it is also possible to select low-carbon mixes. The use of the Embodied Carbon in Construction Calculator (EC3) helps compare cement mixes and select those that offer the best balance between emissions and cost.
This free tool uses data from construction material bids and/or BIM models, alongside a robust database of digital environmental product declarations (EPDs), allowing benchmarking, evaluation, and reduction of embodied carbon emissions with a focus on the upfront emissions from construction material supply chains.

Carbon Risk Real Estate Monitor

At a broader level, tools like the CRREM (Carbon Risk Real Estate Monitor), developed by the European Union, have been introduced to accelerate the decarbonization of the real estate sector.
CRREM helps increase resilience—from an energy and commercial value perspective—in a world dominated by global warming.
It is based on datasets and models that outline decarbonization pathways specific to the real estate sector, enabling companies to evaluate and align their properties with emission reduction targets established by international agreements, such as the Paris Agreement.

The Innovative Off-Site Construction Method

Another highly interesting area is off-site construction: an innovative and sustainable opportunity for the construction sector that allows building components to be manufactured in factories and later assembled on-site.
This approach improves the quality and precision of components, reduces construction times, and minimizes material waste. Additionally, working in a controlled environment optimizes production processes, enhances worker safety, and reduces the environmental impact of construction sites by minimizing emissions related to transport and material handling.
Off-site construction is particularly advantageous for sustainable building projects and modular construction, paving the way for innovation and growth in a sector increasingly oriented toward efficient and low-impact solutions.

Conclusions

Ultimately, adopting a holistic and multi-level approach is essential to achieving significant emission reductions in the construction sector.
Additionally, a collaborative relationship between designers, companies, and regulators is needed, alongside increasing awareness and training, to manage construction processes attentively and effectively.