Much of the talk about green buildings centers on operational energy consumption and, increasingly, carbon emissions. But there are many aspects of sustainable commercial buildings, and one that’s garnering more attention lately is the massive amount of waste generated during construction and demolition. The statistics are eye-popping when you take a closer look. Construction and demolition in buildings, roads, bridges, and other sectors generate more than 600 million tons of waste annually in the U.S., according to the EPA. That’s twice as much waste as what municipalities collect from homes and businesses in cities.
About 100 billion tons of raw material is extracted from the earth every year, equivalent to destroying two-thirds of Mount Everest’s mass annually. Approximately half of that raw material goes into building construction. It’s estimated that construction creates a third of the world’s overall waste; unfortunately, much of this waste ends up in landfills. More building owners are tackling the construction waste problem as it becomes incorporated into increasingly stringent green building standards.
One example of a building using new techniques to cut down on construction waste is the Kendeda Building for Innovative Sustainable Design at the Georgia Institute for Technology in Atlanta. The building earned the Living Building Challenge (LBS) certification in 2021 which is known by many as the most rigorous and ambitious green building standard in the world. The Kendeda Building is just one of 28 buildings globally that have achieved it and the first in the Southeastern region of the U.S. One of the ways the building garnered the certification was by eliminating more than 99 percent of its construction waste and incorporating reclaimed materials into the project.
Skanska, the world’s 5th largest construction company, served as the project manager for the Kendeda Building’s construction, and they had their work cut out for them in reducing waste according to the Living Building Challenge requirements. Under LBC, building projects must incorporate one salvaged material per 500 square meters of gross building area. That meant 10 salvaged materials for the Kendeda Building, many of which had to be locally sourced. Nearly all waste from the development had to be diverted from landfills, including 99 percent of metal, 99 percent of paper and cardboard, and 100 percent of soil and biomass.
Before construction began, Skanska’s team compiled a list of expected waste streams from each trade. All the salvageable material was either incorporated into the development or donated to the Lifecycle Building Center in Atlanta, which captures building materials from the waste stream and directs them back to the local community for reuse. About 443 tons of asphalt were recycled from the project, and the construction team prevented about 99.5 percent of scraps and unused materials from being turned into waste.
The Skanska team also got creative in the use of salvaged materials. They set aside a small warehouse about 1.5 miles from the construction site where they were able to stockpile salvaged building materials, including slate tile that was removed from a Georgia Tech campus building. Granite from the campus’ Archives Building was used for landscaping the building site, and storm-fallen trees were collected, milled, and dried for counters and benches. The project team removed 1880s heart pine joists from a campus building to use as stair treads.
Meeting all these waste reduction requirements was far from easy, requiring constant vigilance until the project was done. Plenty of material still had to be hauled away from the site despite the reuse of soil, logs, and lumber scraps. Sending building materials to recyclers was a last resort. The recycling effort required massive sorting and tracking, and the changing cast of subcontractors had to get used to this novel way of doing things. Most construction sites use one bin for waste and one for mixed recycling, but the Kendeda Building had recycling bins for gypsum, metals, paper, insulation, and wood.
Shan Arora, the Director of the Kendeda Building, told me that a big part of designing this ultra-sustainable building was to be an example and roadmap for other U.S. commercial green buildings, especially in the Southeast. While net-zero waste efforts were challenging and even frustrating sometimes, the idea was to look at building materials differently and perhaps influence other building owners to do so. “We wanted to change how buildings are thought about,” Arora told me. “My goal is to push people with their building projects to think beyond what their building can be.”
Waste diversion and reduction are just one of the many impressive aspects of the Kendeda Building. The building is an example of regenerative design, an increasingly popular architectural concept that goes beyond mere sustainability and aims to be self-sustaining and produce net-positive environmental impacts. The Kendeda Building’s energy-efficient electrical and mechanical equipment, tight building envelope, and solar panel canopy supply 225 percent of the building’s energy needs annually. The solar panel canopy on the roof also captures rainwater. The water is then stored in a 50,000-gallon cistern in the basement, treated, and used for all building purposes, including drinking.
While the Kendeda is impressive and has won multiple awards, not all new building projects have the capital and funding to meet these standards. The building is about 13 percent more expensive than a comparable building at Georgia Tech at $544 per gross square foot. The Georgia Institute of Technology also received a $30 million grant from the Kendeda Fund to build the state-of-the-art green building. It was the biggest donation ever given by the Kendeda Fund and the largest one ever received by the Georgia Institute of Technology. The building was explicitly designed to meet the Living Building Challenge 3.1, and $25 million of the donation was used in construction, with the remainder set aside to support programming activities.
Arora frequently gives tours of the Kendeda Building to architects and building owners seeking to learn what’s behind their accomplishments. He said numerous building projects in the Southeastern U.S. have been inspired by the building, but he acknowledged other projects have more limitations. “I say to building owners, you have to deliver something without the foundation funding that we have,” Arora said.
The circle of (building) life
While not every building developer will have the wherewithal to create something like the Kendeda Building, there are still ways to reduce and divert construction waste from landfills, many of which are attributed to the idea of a ‘circular economy.’ The circular economy concept means replacing waste systems that extract resources with a circular system that keeps products and materials reused. In construction, the idea places value on building material waste as a commodity and not something to be just tossed aside. The cycle recovers and restores materials through re-use, repair, and re-manufacturing. This is what the Kendeda Building accomplished by following the Living Building Challenge certification guidelines, and while other building projects don’t have to aim for that high of a goal, they can still incorporate circular economy practices.
Using circular economy practices in building construction and demolition first means reducing the volume of new materials used. That means preserving existing buildings and prolonging their life. Salvaging and re-using materials have already been a part of building construction, but new ways of re-purposing materials are being considered. Tracking waste from building sites more closely is essential, and separating the waste and transporting it to the correct and certified recycling facilities for processing is the next step.
A prime example of circular economy practices in building construction is the Catherine Commons Deconstruction Project, a collaborative effort with the Circular Construction Lab, a nonprofit organization, and the architecture firm Trade Design Build. The project centered on developing 300 new housing units near the Cornell University campus in Ithaca, New York, which required the demolition of 11 early 20th-century residences. The team convinced the developer to salvage nonstructural elements from 10 demolished buildings and completely deconstruct the other building.
During a week in January 2022, eight workers meticulously cut the roofs, walls, and floors into sections, loaded them onto a truck, and delivered them to a local warehouse for processing. After processing, more than 50 community members and smaller contractors have purchased the salvaged materials, including structural timber and oak flooring. It’s estimated that the structural timbers salvaged from the deconstructed house equated to more than 13 tons of embodied carbon being diverted from a landfill.
Gensler is another firm that has taken the lead on the construction circular economy, applying the principles to the interior design of Google’s $2.1 billion office headquarters project at St. John’s Terminal in Manhattan. The building has been partially fitted out with recycled construction waste, such as scrap gypsum board, diverted back to the manufacturer, and then re-purposed as new gypsum board products. Gensler says that as of April 2022, the project’s interior design had used about 200 tons of recycled materials.
Barriers to overcome
While approaches like this show promise, barriers to the widespread use of circular economy practices in building development persist. The biggest one is economic. Deconstruction of buildings to gather salvageable materials is more expensive than standard demolition, as it demands more time and labor. Typical demolition practices focus on the fastest and most efficient way to get the job done, and the challenges of recovering materials during deconstruction aren’t appealing to most contractors.
Disposing of building materials in landfills is also faster and cheaper than diverting them to warehouses to be salvaged. Building construction for developers is often all about getting the job done quickly, and extra time leads to additional costs. During a time of rising building materials prices and other costs for contractors from supply chain problems and labor shortages, any extra costs added to development aren’t welcome.
Transitioning to a circular economy in building construction is also a significant culture change for developers and property owners. Consumerist societies, especially in the U.S., see waste as inevitable, and many may even have a bad image of salvaged materials. It’s like getting second-hand clothes from your sibling, right? While some developers may embrace this thrift-store mentality, it’s easy to see how many in America are attracted to new and shiny things, including when they think about commercial buildings.
Reducing construction waste can work in the commercial real estate sector, but it’ll take time for concepts like the circular economy to sink in. Many building contractors are reluctant to change and don’t want to modify the usual way of doing business. For most building developers, unfortunately, it’s about getting jobs done ‘quick and dirty.’ Pressure from state and local building regulations and codes may push the ball forward, and the stricter standards for waste conservation in popular green building certifications like LEED will apply pressure, too. For example, LEED 4.1 standard has several credits geared toward construction and demolition waste management. As more tenants today demand green-certified buildings, this could push developers and owners to tackle construction waste more.
Any progress toward reducing building construction waste is welcomed because materials waste has become a growing and massive global problem. According to the EPA, construction and demolition waste generation in America increased by 342 percent between 1990 and 2018, and there’s little sign of slowing down. On a global scale, waste of all kinds is predicted to increase by 70 percent by 2050 if action isn’t taken, according to the World Bank.
Cutting-edge regenerative buildings like the Kendeda Building are an example of new developments that can reduce construction waste streams substantially, even though not all contractors and developers can meet that high standard. Real estate developers will not be able to reduce construction waste overnight. Incremental improvements to the process can be a goal and another essential aspect of pushing the real estate industry to greener and more sustainable standards.
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