Is concrete a sustainable construction material?

Sustainability is a hot topic in general, and the construction sector is no exception. Sustainability is also a very broad concept that, depending on context and perception, can be explained in a multitude of ways, leading to a wide variety of definitions. In that respect, the world of construction is also no exception, as is apparent in the results of USP’s latest Contractor monitor which focuses on contractors’ perception of and attitudes towards sustainability and circularity in eight European countries. The variety of contractors’ perception of sustainability leads to interesting and sometimes conflicting ideas of, for instance, what the best examples of sustainable materials are.

Sustainability in construction is often inherently linked to environment friendliness, for instance in regulations from government institutions that aim to reduce the negative impact of construction processes and constructed buildings on the environment. Given the focus on climate change, the reduction of the carbon footprint of the construction process is apparent in most of these.

Environmental friendliness 

In that light, it is no surprise that environment friendliness of materials and products is the characteristic that European contractors attribute to sustainability the most on average. Although percentages vary between countries, in five out of eight countries environmental friendliness was the most-mentioned characteristic of sustainability. In line with these outcomes, when asked which materials contribute the most to sustainable building construction, the most-mentioned material was wood or timber. Again no surprise, as timber has spent a lifetime absorbing carbon dioxide before it started its second life as a construction material.    

What is surprising though, is that the second most-mentioned material contributing to sustainability is concrete, and the third most-mentioned material is bricks. Concrete is renowned for the impact the production of its core ingredient, cement, has on the environment in terms of CO2 emissions, and bricks are pretty useless without cement as well. So why are these materials considered to be contributing to sustainability?

European Contractor Monitor H1 2020 

The answer is found in the semantics of the concept of sustainability. Although about a third of the European contractors named environment friendliness as characteristic of sustainability, the second most-mentioned characteristic is long-lastingness of materials and products used in construction, mentioned by about a quarter of the contractors. From that perspective concrete makes sense, because when it comes to long-lastingness, concrete is a tangible winner. 

About the Pantheon

In fact, we are often confronted with the durability of concrete in everyday life. Most people in Europe do not have to travel far to find a concrete building that is older than they are, that will probably outlive them, and that can easily outlive the purpose the building was initially designed and constructed for. An extreme example is the Pantheon, the oldest building in Rome that has been in continuous use for almost two millennia. First built as a temple for all gods and later turned into a Christian church, a variety of deities have been worshipped under its massive dome that was built out of  non-reinforced concrete almost 1900 years ago.

So if long-lastingness is considered an important characteristic of sustainability, in the context of an extreme example like the Pantheon, concrete is indeed a material contributing to sustainability. However, the whole argument does depend on the definition of sustainability.

All this goes to show that sustainability in construction is a concept of which the definition is not set in concrete. In the above, we have only touched upon the dichotomy of the top two characteristics of sustainability and sustainable materials that were mentioned by European contractors in general. Many more characteristics were mentioned and their importance varies widely between countries, just like governmental regulations aiming at sustainable construction vary between counties.

Although contractors perceive the government and architects as the main drivers of sustainable construction, the same contractors have a major influence on brand choice. That means that any manufacturer of construction material that markets its products as sustainable, be it made of concrete, timber or any other material, would be benefitted by knowing how contractors actually perceive sustainability. 

For more detailed information, we refer you to the European Contractor Monitor H1 2020