Concrete, steel or wood: understand the environmental impact of each material

The environmental impact of a building begins long before construction is completed. From the extraction of raw materials to manufacturing processes, transportation, and disposal, every design choice has consequences for the environment. In this context, sustainability requires a perspective that considers not only the origin of materials but also their performance and durability over time.

Composto por solo e cimento, o tijolo solo-cimento é uma alternativa eficiente e econômica para construções sustentáveis, garantindo durabilidade e conforto térmico. Uma solução que promove a construção responsável e o uso consciente de recursos. (Cimento Itambé/Divulgação)

Among the most widely used materials in civil construction, concrete, steel, and wood present distinct advantages and challenges. The consumption of natural resources, carbon emissions, and possibilities for reuse vary according to the production and utilization processes of each one. Understanding these differences is essential to evaluate the environmental impact of construction and guide more conscious choices.

Between emissions and durability, the impacts of concrete

Concrete is one of the most widely used materials in civil construction and is also associated with a significant share of the sector's emissions. This happens mainly because of cement, one of its main components.

During cement manufacturing, limestone is heated to high temperatures, a process that requires a lot of energy and releases carbon dioxide.

Projeto de Alexandre Dal Fabbro. (Fran Parente/Divulgação)

On the other hand, the material has an important characteristic: durability. Well-designed and executed structures can remain in use for many decades, reducing the need for frequent replacements.

In addition, concrete waste can be crushed and used as recycled aggregates in certain applications.

Laje in loco. (Hipermix - Concretos/Divulgação)

Another point of attention is the amount of material used. Strategies such as structural optimization, the use of concretes with lower clinker content, and the incorporation of supplementary cementitious materials can help reduce the emissions associated with the material without necessarily compromising its performance.

Steel combines high energy consumption and recycling potential

Steel also has a significant environmental footprint, especially because of the energy required for its production. Manufacturing from iron ore involves high-temperature industrial processes and can result in substantial emissions of greenhouse gases.

(Pinterest/Divulgação)

The advantage lies in the possibility of reuse. Steel can be recycled many times without losing its main properties, and scrap is an important raw material for steel production. In projects that use metallic structures, the possibility of disassembly can also facilitate the reuse of components.

(Jf Martin/Unsplash/Divulgação)

In addition, the strength of steel makes it possible to create structures with less material in certain situations. The environmental assessment, therefore, should not only consider the product's origin, but also its quantity, transportation, service life, and potential for reuse.

In wood construction, the origin makes the difference

Wood is often associated with low-impact construction, but this relationship depends on how and where it is produced. When sourced from responsible forest management and traceable supply chains, it can offer environmental advantages over materials whose manufacturing depends on more energy-intensive industrial processes.

(Maíra Acayaba/Divulgação)

Trees remove carbon dioxide from the atmosphere during their growth, and part of that carbon remains stored in the wood while the product is in use. For this reason, projects that use certified wood from responsibly managed sources can contribute to emission-reduction strategies.

(Felipe Araújo/Divulgação)

However, wood is not automatically sustainable. Deforestation, illegal extraction, long-distance transport, and improper disposal can significantly increase its environmental impact. It is also important to consider treatments, glues, and other components used in industrialized wood-derived products.

Is reforestation wood always a sustainable choice?

So-called reforestation wood is produced from trees grown specifically to supply the industry, such as pine and eucalyptus. Unlike wood extracted from native forests, its production can take place in areas designated for forestry cultivation, which helps reduce pressure on natural ecosystems when there is proper management and production planning.

(Dorelys Smits/Unsplash/Divulgação)

But the term alone does not guarantee that the material has a low environmental impact. It is important to consider the origin of the wood, management practices, land use, the biodiversity of the area, and the distance traveled to the consumer. Certifications and traceability systems can help verify whether the raw material follows established environmental and social criteria.

(Alex Jones/Unsplash/Divulgação)

Another point is that the destination of the wood also affects its impact. When used in long-lasting furniture, structures, and finishes, it keeps carbon stored during its period of use and can extend the useful life of the resource. Therefore, more than choosing a specific species, it is worth looking at the entire production chain and prioritizing materials with known origin, responsible management, and high durability.

So, which material is more sustainable?

There is no single answer to this comparison. The environmental impact of a material depends on its entire life cycle, from the extraction of raw materials to manufacturing, transportation, use, maintenance, and final disposal.

(Divulgação/Divulgação)

Therefore, a more conscious choice considers the specific needs of the project. Instead of looking for a universally sustainable material, architects and designers can evaluate durability, quantity used, origin, possibility of reuse and recyclability.

The combination of different materials can also be a strategy. A project may use concrete where its mass and strength are needed, steel in specific structural elements, and wood in components that favor lower impact, comfort, and the use of renewable resources.

This text was developed with the assistance of CASACOR Publisher, an exclusive content agent developed by the CASACOR Technology team based on the knowledge base of casacor.com.br. The generated content was subsequently edited by Yeska Coelho.