Carbon footprint, circularity and environmental sustainability are terms that are increasingly present in many professional fields, but what do they mean? How do they relate to architecture and the built environment? We spoke with civil, environmental and sanitary engineer Lucas Rosse Caldas about these and other emerging architectural issues.
Lucas is a professor at the Graduate Program in Architecture at the Federal University of Rio de Janeiro and the Civil Engineering Program at the same institution. He participated in chapter 9 of the sixth report of the Intergovernmental Panel on Climate Change (IPCC) on buildings. He wrote several scientific and technical articles about architecture and sustainable construction.
Romullo Baratto (ArchDaily): What is the relationship between carbon footprint, sustainability and circular economy? How do these concepts relate to architecture?
Lucas Rosse Caldas: All these three concepts are directly and indirectly related. The carbon footprint can be defined in a simplified way as the assessment and quantification of the balance between carbon emission and stock (CO2 and other greenhouse gases - GHG) of a product, process or service. Sustainability, on the other hand, involves the classic environmental, economic and social tripod that needs to be related and well aligned so that we have a possible development for the current and future society. The circular economy can be understood as a type of economic development that requires closing cycles with the reuse of waste and resources and reducing the speed of material cycles to develop reusable and durable products. Besides the environmental and economic benefits, this process should positively impact society. All of them are related to architecture, as our sector is one of the largest consumers of natural resources and emits polluting gases, mainly CO2, and generates a large amount of waste.
People live in built spaces, and depending on how that built space is designed, they can consume a lot more resources and generate a lot more environmental impacts. A simple example: in a building designed to be thermally comfortable, the resident will spend much less energy (with air conditioning, for example) and, consequently, less money, and generate less CO2 and other polluting gases in the production and distribution of this electricity. If the building uses less energy, the resident will be able to invest that money in other things (related social impact). Everything is interconnected, and this is even more important for people in less privileged social conditions.
RB: How do you see the role of the circular economy in the construction industry today? What about in the near future?
LRC: It is still very early. First, most professionals working in the area don’t know the concept yet. It has grown within research and teaching in recent years, but there is still a lot of space to be conquered. The role that I see is to encourage the use of reused materials and think of strategies related to reducing the consumption of natural resources. However, as I said, it still has a more theoretical and educational rather than practical role. It is expected that professionals will be more engaged in the topic and that legislation and regulations will require several circular economy strategies. Many financing institutions connected to the sector already show that this is a point of no return. In this way, it is awaited that the circular economy will play a central role in the construction industry in a future that I believe to be very close. It will guide many of the sector's strategic decisions.
RB: Is it already economically viable to apply circular economy solutions in conventional small and medium-sized projects?
LRC: Yes. There is a wrong idea that many solutions aimed at sustainability and circular economy are restricted to large, specific projects. We can think of solutions for different scales, from the choice of furniture to the construction of an entire building.
The sector digitalization and the advent of several information and communication technologies (ICTs) have greatly facilitated this process. It occurs mainly due to the application of platforms and apps that have business models linked to the use of reused materials, which makes all the logistics and access to product information easier, something that would be very difficult before. And, of course, as a given resource or raw material become scarcer, the alternative that comes from some type of reuse tends to become more competitive.
I always suggest that my students ask the following question: "Do I need that product or the service that that product offers me?" If I don't buy that product, I avoid spending on logistics, inventory, waste management and all the problems involved. Industry professionals must verify what they really need in each project.
RB: Besides the reuse and recycling of material resources, what other strategies can be applied to make a project more aligned with the idea of circularity?
LRC: The circular economy goes much further. Of course, using waste is an important strategy, but before that, one must think about not generating this waste. More industrialized and rationalized construction solutions or compatible design processes, for example. If I reduce the consumption of a given resource or product, I will reduce the amount of waste generated.
Another important aspect of the circular economy is material consumption. The most sustainable material is that which is not consumed.
Architects, engineers and other construction industry professionals must reduce the consumption of materials as much as possible without compromising the quality and performance of the project. Projects that consider energy efficiency, water, the reuse of empty buildings and the use of digital tools that replace physical processes are essential. As I said before, it is necessary to replace the acquisition of products with services.
Prioritizing natural and renewable resources, such as wood, bamboo and raw earth, is also important, as these come from sources capable of regenerating in a few years and usually have a lower environmental impact. Those of biological origin can also store CO2 through photosynthesis, helping to reduce the carbon footprint of buildings. Finally, we must think about the source and need for maintenance of each material or product. Very distant suppliers and materials with high conservation and replacement needs can increase costs and environmental impacts.
I advise professionals and students to ask a few questions:
- Do I really need this material/product?
- Can I reduce the amount of this material/product in my project?
- Is it possible to use any material from reuse and/or renewable origin?
- Is there a supplier close to the job site?
- Are service life and maintenance information available?
- Is it an easy maintenance material?
- What to do at the end of the life of this material/product?
RB: What existing technologies can contribute to this?
LRC: Different technologies can be applied to buildings at distinct stages of their life cycle. Many of them have become increasingly accessible. Many are considered Information and Communication Technologies (ICTs) and are part of the so-called Industry 4.0. BIM, for example, has become increasingly widespread and can be applied in buildings’ design and construction stages. From a model with diverse information, I can make much more assertive decisions and reduce the consumption of materials and waste generation. I can run simulations and predict how the thermal and energy performance of a building will be in the future.
At the construction stage, production technologies — such as more efficient equipment for transport and logistics — or even construction technologies, such as 3D printing, have shown great potential. Regarding the Internet of Things (IoT), sensors offer real-time data on the construction or use of the building, facilitating predictive maintenance and saving energy and other resources. In addition, the famous QR codes make a series of applications possible, making information management in the building’s project, construction and use easier.
Using drones during construction and maintenance saves time and prevents accidents at work. Techniques that employ artificial intelligence and machine learning to increase productivity make it possible to obtain information faster and more assertively. The construction of a virtual world based on Virtual and Augmented Reality also has great potential since they replace the manufacture of physical things (models or decorated apartments), saving time, money and materials. Some database platforms already provide information on building materials’ energy, water and carbon footprint. Others specify the origin of a given product, the recyclable material content and what to do at the end of its life. Finally, many of these technologies are already present on our cell phones in the form of apps, making the process friendlier and faster.
Although many of these technologies are still very expensive and difficult to access, the tendency is for them to become increasingly cheaper and for the sector to start absorbing them in its day-to-day activities. So we hope!
This article is part of the ArchDaily Topics: Circular Economy. Every month we explore a topic in-depth through articles, interviews, news, and architecture projects. We invite you to learn more about our ArchDaily Topics. And, as always, at ArchDaily we welcome the contributions of our readers; if you want to submit an article or project, contact us.
