For years, architecture aspired to last forever. Roman construction, cathedrals and ancient temples were all conceived to resist the passage of time. From the Industrial Revolution onward and especially with the increase in demand for housing linked to urban development, speed became the priority. Much was built, very quickly and with the present in mind more than the future. Today, when these buildings fall into disuse or become ruins, many materials are seen simply as waste.
In the circular economy, however, the end of a building does not necessarily lead to its demolition, but an opportunity to give new life to its various components. So-called “design for deconstruction” proposes conceiving of structures from the very beginning so that, when the time comes, they can be disassembled piece by piece and each element recovered, thus avoiding tons of waste. This is not yet a common practice, but it is essential for rethinking how we live and how we design the spaces around us, fostering a more flexible and aware architecture, able to regenerate itself.
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In 2002, the architect William McDonough and chemist Michael Braungart published Cradle to Cradle, a treatise which broke with linear “cradle-to-grave” logic. As Seville University professor M. J. Agudo-Martínez, explained, the book “signifies a radical revision of the design process, based on three principles inspired by nature: the transformation of waste into raw materials, the use of clean and renewable energies, and the commitment to natural and cultural diversity.” This perspective now manifests itself in Cradle-to-Cradle (C2C) certification, which is internationally recognized with respect to the design and manufacture of products made according to the circularity principle.
Applied to architecture, this means thinking of buildings as modular systems, where the pieces are assembled without adhesives or other irreversible mixtures. Every screw, beam or panel becomes an identifiable element, dismountable and re-usable. Incorporating circularity into construction and use of materials can have an enormous impact in the fight against climate change and waste reduction.
According to the United Nations, changing the way in which we produce and use steel, aluminum and plastic can reduce emissions from these industries by up to 40% by 2050. The use of recycled or re-used steel could also save up to 25% in costs per ton in construction. The application of circular principles to the sector would also allow the reduction of materials and costs through strategies such as modular production or 3D printing, optimizing energy use and recovering high-value materials at the end of the useful lives of buildings.
“Demolish” signifies “destroy, raze, reduce to rubble”. Deconstruct, on the other hand, implies understanding before undoing, separating with care to re-assemble in another form. This is the difference between a linear system – extract, use, throw away – and a circular system, where each component conserves its value within a continuous cycle.
José María González Barroso, Albert Estruga Rey and Paula Martín Goñi explain that so-called “design for deconstruction” “proposes a new way of understanding the project’s constructive technology, which goes beyond management of the resources needed to carry it out, and demands a strategy for managing resources that will be produced in the demolition or disassembly of the building at the end of its useful life”.
It is also recommended we come up with a hierarchy of strategies to determine how, and at what scale, it’s possible to intervene in buildings to reincorporate wastes into the productive cycle. The top strategy would be aiming to re-use the whole building, implying its complete recovery through renovation, restoration and even relocation processes. Then comes re-use of components, embracing standardized elements that can be exchanged or easily handled. Lower down the scale would be a strategy to re-use materials, aimed at re-processing them to create new components. Materials recycling occupies the bottom level of the hierarchy, given that energy consumption and pollution linked to this process can, in some cases, exceed, the impact of using new resources.
This approach demands research, traceability and documentation. In Europe, initiatives such as Madaster, or Buildings as Material Banks (BAMB), promote so-called material passports - databases which register the origin, composition and value of each building component. Traceability ensures that the materials can be recovered decades later for a new use. It also leans on life cycle assessment (LCA), a tool which evaluates the environmental impact of a material from its extraction to possible re-use.