It’s well established by now that the construction material production industry is the biggest energy consumer at the global level, with over 3 billion tonnes of raw materials and accounting for nearly 50% of global steel consumption. Buildings are often created with only one function in mind, when societal needs or user preferences change, these mono-functional buildings usually become outdated or even obsolete. Refurbishing turns out relatively expensive, so the buildings are demolished and reconstructed, generating a lot of waste that predominantly ends up in the landfills. Current practices use a lot of resources in an ineffectual way, but a positive impact can be created by feeding them back to the production stage and reducing the extraction of virgin raw materials.
Typically, a building is constructed, used for 50-100 years, and then demolished at the end of its life forming a linear approach wherein materials quickly reach the end of their lifecycle. Circularity is about maintaining a regenerative built environment by keeping the materials in a loop, such that they can be easily separated and recycled at the end of their life, hence minimizing waste.
Envisioning the buildings as material banks, seeing the building not as a fixed and final object but rather as temporal and dynamic storage of valuable materials and components, a building that can easily be changed in response to changing needs and preferences which can be disassembled into parts that can be used again for a new purpose.
Circularity enables us to view buildings as machines that can be dismantled so that the materials can be recycled or if in a good condition reused in the same/some other structure, hence designed for disassembly. The crucial aspect is the design of connections which need to be mostly dry in nature. Wet connections like sealants, glues, etc. act as barriers while separation and repurposing. Adoption of systems like screwing and bolting makes objects easily dismantled. Another consideration to keep in mind is to place elements in such a way that you can reach them easily, which needs for a new system of organization of building layers. For example, pipes and surfaces in a building should be reachable for effective maintenance and can be taken out when needed.
Frank Duffy’s concept of looking at the building in the form of layers claims that the approach has a long-term economic, social, and environmental impact.
1st Layer- Site is eternal can have a positive or negative impact, depending on how it’s treated. What we choose to develop considering the climate social cultural and economic aspects matters.
2nd Layer- Structure has the longest life range 50 to 100 years, quality of the structural framework needs to be crucially examined. Insulation and services might be a part of it but need to be accessible.
3rd Layer- Skin, façade and roof life is typically 20 to 50 years to keep up fashion, technology, or wholesome repair. It has a long-term impact on energy performance and occupant comfort inside the building.
4th Layer- Services, working guts 7 to 15 years. These comprise the wiring, plumbing, fire extinguisher systems, air conditioning, heating, and ventilation. Proper access to these aids’ longevity by adaptability.
5th Layer- Space Plan (interior layout) is revamped every 3 to 30 years, walls, floor, doors, surface fixtures, etc. are considered mutable, changeable without change in structure.
6th Layer- Stuff, it changes according to the user on a daily to monthly basis, this includes appliances, furniture, electronics, art, etc.
An important aspect will be to understand the resource flows that enter circuit and leave the urban environment every day that include water, energy and waste. Circularity is not limited to materials, it also focuses on other buildings' processes and activities like services, resource flows, and consumptions. Behavioral changes also play an important role in reducing non-material resource consumption and it’s about time we realize how much can one consume keeping the population explosion in mind. Taking shorter showers, consciously producing less waste, not unnecessarily keeping light and fan switches on, making a conscious effort to follow the reduce, reuse, repurpose and recycle as a lifestyle change tends to keep resources in a loop for a longer duration.
Currently, the energy systems are centralized, but buildings are capable of producing the energy to meet their requirements by installing Photovoltaic Panels on roof and facades along with micro wind turbines to generate electricity locally. Further, reduction in the energy consumption of different activities can be accelerated by the use of energy-efficient appliances. Ways to change the flow of water in a household can also be rethought, besides proper conservation and rainwater harvesting, cascading the water inside washrooms with little treatment is a great repurposing strategy to implement.
The cost of circularity is high as the concept is in its pioneering stage. Design of connections up meets the desirable strength is crucial and might take some time to standardize and effectively be in place.
The credit of proper working of this system goes to different stakeholders which are architects, engineers, designers, policymakers, recyclers, builders, manufacturers, contractors, suppliers, and uses. Building a strong value network takes time and the active participation of all parties.
Keeping track of materials so that toxic materials are avoided, assuring quality and safety of reused materials. (Material passport needs to be in place which gives all the information regarding the lifecycle of the material)
Assembly of walls might be difficult, too often walls are structural elements as they connect the building vertically and contain concealed MEP systems.