Buildings are responsible for nearly 40% of the world’s carbon emissions. When a building is demolished, it leaves behind a huge pile of waste. The continuous increment of construction projects worldwide is raising the amount of waste in landfills, which is critically impacting the economy and the environment. What would it take to design a building for its life and so it can be deconstructed after its usefulness has passed?
An emerging group of architects, engineers, contractors, and designers are determined to find a new way to build, some of which are chronicled in a recent New York Times article. With a common philosophical belief in a circular (also occasionally called regenerative, cradle-to-cradle, or doughnut) economy, they feel the ideal process for removing an old building would be to disassemble it and reuse its parts.
Circularity emphasizes the composition of things, rather than their use. In this way of thinking, anything made thoughtfully enough can endure infinitely or proffer its molecules for breakdown and reorganization.
However, within the building sector, the transition from a linear to a circular economy is still at a very early stage.
A building’s lifecycle can be divided into 5 different stages: design, production, construction, use, and end of life. There are two main tenets to considering lifecycle as part of eventual construction debris:
- First, on a planet with limited resources and a rapidly warming climate, it’s crazy to throw stuff away.
- Second, products should be designed with reuse in mind.
We’ve written a lot about the first tenet of recycling at CleanTechnica: lead acid batteries, solar panels, household goods, wood, electronics, plastics, and more.
It’s the second tenet that’s less commonly accepted and more problematic — how can we get companies to reassess their businesses in the most basic ways? Recycling built structures would require a complete rethinking of what it means to plan infrastructures in much longer time scales. Given the compelling threats of global climate change, sustainable construction is the way forward for the building industry to play its part towards achieving a sustainable and healthier world.
Creating a truly circular building economy, though, is quite challenging.
The Problem with Construction Debris
For the next 4 decades, built space comparable to the square footage of another New York City will be added to the planet every month. Resource utilization of construction and demolition waste is regarded to be an important means of achieving the sustainable development of the economy and the environment. Recasting waste as material as a matter of policy is complicated. In the circular system, everything is used. Instead of being discarded, waste is collected in distinctive spaces where it is made anew. In this futurescape, building materials meld as one into the environments from which they emerged.
The construction industry is one of the most environmentally detrimental industries in the world. It impacts directly the use of raw materials, their determination of use involving the whole lifecycle, and the surrounding environment. The current and common barriers to that reality are stark and include:
- standardized building components made with composite materials
- rigid supply chains
- fixed laws and contracts
Clearly, the transition from a linear to a circular economy within the building sector is still at an early stage.
That’s because materials have a very complex nature. Nearly everything in our built environment is permeated by chemicals derived from fossil fuels. As UPenn relates, for more than 50 years a majority of construction materials have been engineered using polymers for the purposes of achieving a range of advanced performance capacities. Polyvinyl chlorides are used in plumbing supplies, exterior sheathing, interior surfaces, furniture, and landscaping.
The petrochemical industry has lobbied to shape local building codes and encourage architects and engineers to incorporate new composite materials into their designs. The result is that everything is embedded with the fibers, coatings, and pigments from essentially oil and gas derivatives, and that makes reuse difficult. More often than not, it’s more expensive to refurbish than to build new.
A New Paradigm of Building Materials
What kind of business models are needed so new and improved methods and innovative services can lead to a net reduction in the use of resources and minimizing the construction waste disposed of on landfills? There are different possibilities about buildings’ after-life options: maintenance, refurbishment, demolition, and deconstruction.
Circularity advocates also say it’s not just about materials, but about how the overall economy is structured. Strategies like organizing temporary bins in each construction zone and identifying construction activities that produce recyclable materials have high usability indexes. So does enhancing company policies related to construction waste recycling.
Researchers in Austria outline how deconstruction represents a sustainable alternative to common demolition, which tends to be an “arbitrary and destructive process.” Rather than ruing the effect of construction debris on the environment, they say that the built environment can be considered a key sector for the transition from linear to circular economy. The building industry could:
- contribute to resource efficiency
- improve energy use during the lifecycle of buildings
- incorporate better quality sustainable materials
- mandate more waste recycling
- improve design features across a building’s lifecycle
A Building that is Deconstructed Rather than Demolished
To be able to analyze the deconstructive potential of a building, it is necessary to know how its entire lifecycle works. It starts from the origin: the concept behind its construction, the local context, the choice and origin of materials, and the different types of environmental impacts that make up each lifecycle phase.
This approach allows understanding how each choice made in the design and production phase then has repercussions in the use and disposal phase.
Then deconstruction needs to be separated into two categories, the Austrian authors explain, depending on the relation to structural or non-structural elements.
- Structural deconstruction involves the dismantling of the structural building components that are an integral part of the building and contribute to its stability, such as beams and pillars for rigid frames and walls made by bricks for load-bearing systems. It needs a range of tools and equipment, heightened safety considerations, and a time frame of days or weeks to be realized. It is not always possible and is dependent on the construction technique — does it allow the connection between the elements in a reversible way or not?
- Non-structural deconstruction consists in the recovery of non-structural components whose removal is not dependent on the structural integrity of the building and that are usually easy to dismount, such as doors, windows, and finishing materials. In general, non-structural deconstruction can be accomplished relatively easy and with few tools, limited labor, and typical job-site safety considerations, usually lasting hours or days. The building components can be removed without destructive approaches and additional structural support.
Final Thoughts about Building Deconstruction
The reuse of construction materials has been common as long as humans have been building dwellings. Today the practice has an ecological importance, with the reuse and recycling of building materials aimed at the preservation of virgin materials and to keep the level of climate pollution due to the construction and use of the building artifacts low.
With upcoming landfill bans and subsidies that support resource conservation, the deconstruction of buildings will likely become a norm in society. That means costs associated with it will be built into construction planning. Socioeconomic benefits of deconstruction will accompany environmental ones, to include increased job opportunities, vocational training, historical preservation, availability of building materials, and small business development in economically depressed areas.
A methodology for the whole planning process must include deconstruction principles at every lifecycle stage. Deconstruction will require connections between the structural and non-structural elements as well as smart materials choices that favor the use of reusable and eco-compatible materials and minimize the use of hazardous materials and compositions. It will necessitate allowing access to information regarding building construction and deconstruction, with the instructions to follow for the correct identification and dismantling of components and their possible reuse or recycle.
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