Destined for the Dump, Construction Waste Gets New Life in the Garden

Construction waste has long been a bane of ecologically minded architects. So a trio of designers zeroed in on what they felt was a particularly egregious example: the “architectural mock-up.”

Created before construction starts on a large real estate development, a mock-up is a one- to three-story model of a facade, often including windows, part of a roof and other features. It is used to test a design before embarking on a project, but afterward, it often ends up in a garbage heap.

“These are brand-new, highly sophisticated, incredibly intelligent assemblages ready to have a new life,” said Ivi Diamantopoulou, an architect who, with her partner Jaffer Kolb, founded New Affiliates, a boutique design firm in Manhattan.

They teamed up with Samuel Stewart-Halevy, a doctoral student in architectural history at Columbia University, to repurpose the structures for practical purposes in community gardens around New York. Their program, called Testbeds, recently completed its pilot project — a jazzy new shelter in a garden on the Rockaway peninsula in Queens — and they hope the example will spur others to find new uses for mock-ups, thus diverting them from landfills.

But it remains to be seen whether Testbeds can be scaled up in a cost-effective program — and whether repurposing mock-ups can make a dent in the real estate industry’s mountain of waste.

“The problem is enormous,” said Felix Heisel, an assistant architecture professor at Cornell University and director of its Circular Construction Lab. “And one of the real problems is that very few people are aware of it.”

Across the country, 600 million tons of waste is generated in the construction and demolition of buildings and infrastructure, according to a 2018 estimate from the Environmental Protection Agency. New York State alone produced more than 15 million tons of the stuff in 2019, according to the state’s Department of Environmental Conservation. A 2003 report indicated that construction and demolition waste accounted for 60 percent of New York City’s waste stream.

“For every bag of garbage people put out on the curb, the construction industry is producing twice as much waste,” Mr. Heisel said.

At a time when TikTok videos of dumpster diving are calling attention to discards, efforts have sprung up to salvage materials from renovations and demolitions so that they can be repurposed. And there is a movement to design buildings that can be disassembled, with their parts reused, as part of an effort to bring about a “circular economy,” a model that focuses on recycling resources.

But waste is generated at the beginning of a building’s life, too, and architectural mock-ups are a prime example of how valuable resources are squandered in the construction process, Mr. Heisel said, pointing to the labor that goes into making the materials, not to mention the climate-warming carbon produced in their manufacture and transport.

Mock-ups, which are a fraction of the size of the buildings they are made for, are often designed by architects and consultants and can cost hundreds of thousands of dollars, industry experts say.

There are two types. The first is a visual mock-up, which is made to try out custom finishes and features and get a sense of how everything will look together on the building; they are sometimes erected right on a construction site.

The second type, a performance mock-up, is built to see how a structure will hold up under use. At testing facilities, they are blasted with water and air to simulate harsh weather and subjected to other trials. In what’s sometimes called a mob test, they may be attacked with baseball bats. After tests are completed, they are often thrown out.

“Right at the moment they prove the building facade system will work, they’re rendered completely useless,” Mr. Stewart-Halevy said.

He and his colleagues are not the only ones who see reuse potential in mock-ups. In Senegal, one from a hospital project was repurposed into a grade school.

The Testbeds designers zeroed in on garden structures after noticing that the casitas and toolsheds in green spaces around New York were about the same size as mock-ups. In 2018, they pitched their reuse concept to the Department of Parks and Recreation’s GreenThumb program, which oversees more than 550 community gardens run by volunteers on city-owned lots throughout the five boroughs.

Carlos Martinez, GreenThumb’s director, was enthusiastic about the idea, which he said was “in the spirit of community gardens,” in which volunteers often cobble together makeshift benches, trellises and various types of structures with whatever materials are on hand.

The Testbeds team identified a facade fragment for the pilot project — a visual mock-up made for 30 Warren, a luxury condo in TriBeCa designed by François Leininger, Line Fontana and David Fagart. Measuring 21 feet by 10 feet, the mock-up incorporated panels of tinted high-performance concrete that had been poured into molds lined with corrugated cardboard for texture; the panels surrounded a big window set in a frame of Champagne-colored anodized aluminum.

The condo’s developer, Cape Advisors, had installed the mock-up in 30 Warren’s sales gallery to help prospective buyers visualize what the building would look like, said David Kronman, the firm’s president. Once the condo units were sold and the sales gallery closed, Cape Advisors helped arrange storage of the mock-up for Testbeds.

Mr. Martinez introduced the designers to organizers who had been working to start a community garden on a weedy vacant lot in the low-income neighborhood of Edgemere in the Rockaways.

“We wanted a greenhouse, a classroom, a space that could be used when the weather was bad,” said Alexis Smallwood-Foote, one of the garden organizers and a longtime resident of Far Rockaway.

Completed in August, the modernist structure consists of three rooms under a common roof that also shades outdoor space. The mock-up provided the facade for the largest room, its window bringing light to that space. The rest of the structure was built from off-the-shelf materials like pressure-treated lumber for framing and corrugated metal for the roof.

The project has garnered recognition — it will be part of an exhibition at the Museum of Modern Art — but there are financial hurdles to overcome before Testbeds can be rolled out more broadly.

The designers raised the $70,000 needed for the shelter through grants, private donations and in-kind contributions. They hope to secure a funding stream for future garden structures — one idea is to have the developer donating a mock-up pay for the entire conversion project. Because the size and design of future structures will depend on the needs of gardeners and site conditions, costs will vary.

On a recent morning in the Garden by the Bay, as the Edgemere garden is called — where sea gulls swooped and, farther overhead, planes ascended from nearby Kennedy International Airport — the volunteers greeted the designers with hugs and spoke to visitors of their plans.

Jackie Rogers, an Edgemere homeowner who has become the garden’s president, said the volunteers wanted to get electricity to the new building for cooking demonstrations with the produce they were growing, and they have envisioned putting on puppet shows using the large window opening from the mock-up for the stage.

Mr. Heisel of Cornell applauded the way the designers had turned something destined for the dump into a community asset. But he also said mock-ups themselves should be rethought. If they were designed to be broken down with their parts reused in the building to be constructed, the structures could reduce waste and provide a “trial run” for how the building could one day be disassembled.

“The mock-up can become a new tool that foresees a circular economy,” he said.