For years, building sustainability has been assessed primarily through operational efficiency: energy consumption, thermal performance, or emissions associated with daily use. But a less visible – and increasingly decisive – dimension is gaining prominence in the sector: embodied carbon.

 

This refers to the emissions generated before a building even begins operating: from raw material extraction to material production, transport, construction, maintenance, and the eventual end-of-life of components. If operational carbon measures the impact of a building in use, embodied carbon measures the impact of building it.

 

Why does embodied carbon matter?

 

Today we know that a significant share of emissions can occur before a building is even occupied.

 

According to international studies, embodied carbon may account for between 30% and 70% of a building’s total lifecycle emissions (World Green Building Council – Bringing Embodied Carbon Upfront), depending on building typology and materials used. In highly efficient new buildings, that share can be even greater.

 

A few examples help illustrate the scale of the issue:

• Cement production accounts for approximately 7–8% of global CO₂ emissions (International Energy Agency – IEA);
• Steel, another critical structural material, represents around 7% of global emissions (IEA);
• In some office buildings, up to half of the total carbon footprint may be associated with materials and construction, rather than operation.

Sustainability is therefore beginning much earlier: at the concept stage, in the choice of construction systems, in the quantity of material used, and in the ability to optimise solutions before construction begins.

In practice, discussing embodied carbon means asking questions such as:

• Which materials are being used?
• What is their origin and production process?
• Can existing structures be reused?
• How can waste be reduced during construction?

Building better increasingly means building with greater awareness of what is “embedded” in the building itself.

Industrialisation: building with more precision and less waste

 

The industrialisation of construction becomes particularly relevant in this context. More precise, standardised and digitalised methods make it possible to reduce waste, improve resource management and increase process predictability.

Systems such as BubbleDeck reflect this efficiency logic. By reducing the volume of concrete in voided slabs, they contribute to a more rational use of materials and potentially to lowering the carbon footprint associated with the structure.

Reducing impact is not only about choosing different materials. Often, it begins by using less material – and using it better.

 

Urban Regeneration: extending the life of buildings

 

The same reflection applies to urban regeneration. Reusing existing structures can avoid emissions associated with demolition, the production of new materials and ground-up construction.

Regeneration is not only about preserving heritage or revitalising territories. It can also be a concrete decarbonisation strategy, by extending the useful life of buildings and reducing the material impact of interventions.

Projects such as BUZ at La Movida or Spark, developed through the regeneration of a former industrial area, show how regeneration can create new uses without erasing the memory of place. In these cases, adapting existing structures allows urban assets to be transformed into contemporary, more efficient spaces prepared for new ways of working and living.

In this sense, every project decision should consider not only what is built anew, but also what can be recovered, adapted and reintegrated into the city.

BIM and more informed decisions

 

Tools such as BIM reinforce this transformation. By enabling the simulation of solutions, the quantification of materials and the anticipation of conflicts during the design phase, BIM supports more informed and efficient decisions.

BIM can support decisions related to:

• Precise material quantification;
• Comparison between construction solutions;
• Reduction of errors and rework;
• More efficient construction planning;
• Improved lifecycle management of the building.

At Castro Group, BIM has always been understood as a strategic tool. Its adoption resulted from an early recognition of the importance of digitalisation in the sector, helping improve coordination between disciplines, optimise design decisions and strengthen control over cost, timelines and quality.

 

Certifications and a more complete view of sustainability

 

Certifications are no longer merely recognition labels. Today, they function as strategic tools to guide design decisions, measure performance and ensure that buildings respond to increasingly demanding criteria of sustainability, efficiency, well-being and resilience.

In real estate, systems such as LEED, BREEAM, WELL, WiredScore and SmartScore help structure a more comprehensive approach to the lifecycle of assets. Each addresses different dimensions: environmental performance, user health and comfort, digital connectivity, building intelligence, operational efficiency and future readiness.

In the context of embodied carbon, these certifications encourage a more rigorous assessment of materials, circularity, resource sourcing and the efficiency of construction solutions. At the same time, they reinforce an essential principle: a sustainable building must be conceived as such from the outset.

 

 

Embodied carbon makes visible a dimension that for too long remained hidden within the construction process itself. As the sector deepens its ESG strategies, this issue will become increasingly relevant for measuring impact, comparing solutions and making more responsible decisions.

 

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