Form and function. Terms that accompany several definitions that belong to architecture, but more is needed to summarize the practice in 2023. Nowadays, building involves understanding the cycles of materials and how each action can be linked to the extraction of natural resources and their damage to the environment. We live in an urgent need to review the way we produce built space. In this search for models that move away from linear systems and provide a constant process of transformation and redistribution of matter, strategies arising from the circular economy emerge as a possible path. Its application in architectural heritage – for maintenance or restoration – can incentive the necessary changes toward a more sustainable society.
Heritage-listed buildings are of fundamental importance to the urban landscape. Not always landmarks in the city, but certainly spaces that reflect cultural and historical characteristics that help define the local society. Renovating or readapting these spaces is a way of reclassifying urban areas and rescuing important memories. In addition, it sets up an opportunity to integrate environmental benefits into the entire surroundings if it is possible to promote a sustainable intervention.
Working with the circularity of materials (recycling them and avoiding using new ones) is a repeated practice at the Brazilian office RUÍNA Arquitetura. When founding it, Julia Peres and Victoria Braga sought a professional exercise with greater socio-environmental awareness and the appreciation of materials by proposing reuse as an alternative for the civil construction industry. They create new possibilities for salvaged materials, reduce the amount of demolition waste and, with it, provide building materials with a lower environmental impact. In an interview conducted last year, they reminded us that:
(...) there is a very interesting and necessary idea that cities make up the so-called "urban mines": they offer all the material resources needed for their own and constant renewal, without architecture having to resort to the linear model and the extraction of natural resources.
Reforming or adapting the use of a cultural heritage project must always reflect the needs of the communities. Today, reducing the extraction of materials from the environment is the main flag of the circular economy from a civil construction perspective. It directly influences the way we intend to inhabit the world.
Considering the circularity of materials when intervening in urban heritage means structuring the future based on what was created in the past. Thus, the work extends beyond the project itself and enhances its local features by integrating recycled materials and already-known techniques instead of opting for something new that requires the expenditure of natural resources. The meaning of common good gets expanded with contributions to the economic and social development of the area where the building is.
In this case, not adopting new materials does not diminish the quality of innovation in a project. Intervening in cultural heritage buildings requires a transdisciplinary approach that, in the intertwining of different disciplines, resolves several layers of a program and proposes new spatial experiences, in a way that the adaptive reuse of heritage buildings and their elements configures sustainable urban development.
There are different ways to approach circularity and contribute to a project. It is possible to reduce the environmental impact of the life cycle of buildings or influence the entire chain of execution of the work, products and use of the building. Each heritage is unique and deeply rooted in its culture and community, so a universal solution is impossible. However, we can always find ways to adapt them to the context.
Design as Initial Sustainability Decisions
Circularity always points us toward the use of clean energy. To this end, replacing non-renewable energy supplies with renewable means is a necessary first step. Considering passive comfort methods and ways to reuse or recover water are also important for an efficient final framework. In the climatic inconstancy posed by the current crisis, it is worth foreseeing flood risks and flexible ways of working on thermal comfort in the building for extreme heat or cold. In addition, expanding the green area is always a good strategy to maintain a more pleasant microclimate.
In the case of renovation, minimize or eliminate the need to build spaces that require new materials. For this, environments can be less shared and multifunctional. In a better consideration of the environmental impact of the project, a table with the selection of materials and techniques to list the incorporated emissions, how the resources are produced and the means to avoid waste can help to illustrate the steps of the whole project.
The Choice of Construction Materials
The choice of bio-based and sustainably sourced materials — such as wood with the FSC label, for example — sets up a high-level circularity strategy, as biomass can be returned to natural resource stocks over time.
In addition, another alternative is the use of demolition, recycled or readapted materials. It is worth reminding that the closer the material or resources used are to the construction site, the lower the economic and environmental costs of transport and logistics.
Precautions for executing the construction
Respecting the context is one of the best ways to avoid waste. One must know how to limit interference in the natural habitat, such as earth movements and tree cutting. After all, maintaining or improving green spaces is fundamental for the surrounding ecosystem.
Paying attention to traditional techniques, such as vernacular constructions, along with materials easily found in the region, can provide important clues for a building more suitable for the climate, terrain and workforce. It also facilitates the future identification of the public with the work.
Thinking About the Use and the Community That Uses the Space
After the project is complete, its circularity depends on the use that people give it and the instruments offered for this purpose. In addition to water reuse techniques and a highly efficient energy system, equipment that favors the reuse and recycling of waste must be implemented and encouraged (besides separating metal or plastic products for recycling, it is possible to make compost and distribute fertilizer to the community). The collective factor is also fundamental to creating a powerful connection between people and space. Furthermore, the more areas become shared and less individual, the lower the energy expenditure.
Other significant strategies are: claiming to authorities the guarantee of easy access to public transport, avoiding fossil fuels (such as a bicycle path network), incorporating and providing an experience with green spaces to create a sense of belonging for society with the place, which may include vegetable gardens and edible plants.
Is Demolition Necessary? Recycle!
As the partners of RUÍNA Arquitetura remind us, "reusing demolition materials on site is an example of what it means to operate on the smallest of local scales. The material does not even leave the site where it was found and is immediately reinserted in its original or distinct function. Imagine the scope of the change if it was necessary to consider the reuse of materials and demolition waste in every small or medium-scale renovation?”
Therefore, it is always worth evaluating options for the transformation and the adaptive reuse of materials, seeking to experiment with different ways of recycling them. In addition, opting for dismantling, to take advantage of elements such as doors and windows, for example, is an excellent option to avoid complete demolition and loss of materials.
Finally, there is the maxim that circularization starts with the material and extends to people. It is a cycle that is both natural and cultural. All the benefits of working with architectural heritage sustainably and circularly apply to the construction and influence the design and how society uses it. These actions mirror the desire for a possible life and show concern for the future of all beings (human and non-human) on Earth.
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.
