There are a lot of ways to look at the impact of new home construction on the environment. But what if a home can be reused and doesn’t have to be built at all?
Carl Elefante is principal emeritus with the firm Quinn Evans and is known for coining the phrase “the greenest building is one that is already built.”
In his book, Going for Zero: Decarbonizing the Built Environment on the Path to Our Urban Future, he suggests that the culture change we need to take place is to take on the role and responsibility of being stewards of the existing building stock.
“We have to get more benefit and multigenerational benefit from the things that we build,” Elefante said. “We have to rediscover the legacy of building.”
He lives in a 100-year-old home, built by the original owner. His home is an example of the potential durability of a house, and he predicts that his home will last another 200 years.
Reuse As The Future Of Better Building
There are state and local objectives to start address the impacts of construction on the environment, but Elefante believes change needs to happen fast to avoid negative consequences.
“The Syrian and Central American immigration crisis have completely changed the political landscape in the world and those are drops in the bucket compared to what we think the climate migration might look like,” he said. “By 2050, there would be 149 million climate refugees in the world. Central America immigration was 2 million. Imagine 149 million. It would change the world.”
He says that we have to take care of the whole human race as an integrated challenge. There also is an urban imperative—the United Nations predicts that 90% of the world’s population will be living in cities by the end of 2100, which means we need a new way to think about architecture to protect the earth’s resources and to protect its residents.
Putting Reuse Into Practice
In the city of Vancouver, Canada, close to 3,000 single family homes are demolished every year to make room for new construction that is higher density and that can help solve the city’s housing crisis.
Markets like Vancouver that are land locked by oceans, mountains and the U.S. border, have nowhere else to go with housing. So, as the population continues to grow, the need for housing also steadily increases, forcing an urgent need for housing to densify because it cannot sprawl.
In Vancouver, about 20% of the homes that are set to be demolished are in good condition, some being built within the last 10 years.
“There are 600 high value homes torn down every year,” said Glyn Lewis, founder and CEO at Renewal Development. “The more responsible alternative is to pick up the home, put it on a barge or truck and move it to a nonurban location that needs housing. We are that match maker—we find the homes slated for demolition, we modernize them, add insulation, change to double pane windows, to a heat pump, put on a new coat of paint, and take them to a new community.”
The company acts as a general contractor and can build the foundation, and make all the service connections after transporting the home to a new location.
Carbon Benefits Of Reuse
The average 1,500-square-foot, wood-framed home is made with about 100 tons of materials, which all goes to the landfill when it is demolished. In Vancouver, where 3,000 homes are being demolished per year, that adds up quickly to a lot of landfill. Lewis says that one-third of Vancouver’s landfill is demolished homes. A report the company prepared shows the volume of demolition across Metro Vancouver and its future projections.
Renewal Development has moved 27 homes, saving them from the landfill. It also moved a 1910 school house and used that to complete a life cycle assessment that compared the carbon savings against a new construction home. A new construction home can be built at higher energy efficiency and performance levels, but reusing an existing home can still save 24% of carbon emissions over a 60-year time frame, mostly due to the embodied carbon from the new materials.
While Renewal Development is still in a pilot and scaling stage, it is on track to save 50 homes from demolition this year. Lewis’s goal is to do 200 homes per year in British Columbia.
“It’s amazing and rare what Renewal Development is doing,” Elefante said. “It’s heartening to hear that someone is recycling building at that scale. Renewal Development is a great example of that rediscovery of a paradigm that has existed for a long time.”
While not moving whole homes, Angel City Lumber is re-sourcing trees into projects by connecting the design process with the right application. The company’s success is founded on its local knowledge that it applies to 3D modeling, fabrication, project management and general contracting services.
Reuse In Principle
“Circularity is taking your process and designing out waste–what you are trying to do is keep things in flow and get rid of the waste portion,” said Denice Viktoria Staaf, ESG consultant and circularity expert at consulting firm Labeling Sustainability. “When you think about that, prevention, or not using anything is the best, but that’s not possible. Then, you go to reuse, which is way up on the pyramid because it means you don’t need virgin materials. Reusing the home is way better than transferring the materials and way better than recycling.”
Reuse not only reduces the need for virgin materials, if a home is reused in its current form, then reuse also eliminates the need for more material, therefore becoming net positive—not only saving landfills, but dramatically reducing the carbon footprint of the construction.
“The average carbon footprint of a single-family house is 15 to 100 metric tons of CO2,” Staaf said. “When you look at reusing, you eliminate that carbon footprint. Then, you add what it takes to move it, so you’re adding a small portion and removing a huge portion by eliminating the construction.”
In some construction, there is enough data and tracking to add up the operational carbon of the building to understand greenhouse gas emissions. Currently, it’s only done at a limited scale in the U.S.
The global warming potential of a building could be calculated by adding up the amount of carbon in the building, but in order to do that, the carbon footprint of every material in that building has to be available. In the residential construction world, those details are hard to come by.
The Affordability of Reuse
A new, 1,500-square-foot home costs about $1 million to build according to Lewis, and his company is offering the same amount of home at less than half of that cost.
“We filter constantly to find the highest value homes that people would be comfortable in,” he said. “The cost of the home is almost entirely transportation. I am vertically integrated in a way that is unique. One component is sustainable demolition service–I quote as if I am a demo service provider including abatement, trailer removal, etc. Then, I can save some of the homes, so I get the home for free because they are paying me to provide a site clearing service.”
Renewal Development pays for the transport by truck or barge, jack and lift, and a connection to the truck. While it is becoming more popular, lifting homes is still a fairly unique service that only hundreds of companies in North America can offer, and even more rare is a company that will lift them on the road.
“We have to deal with the challenges of moving something that wasn’t designed to move,” Lewis said. “There also are homes that are too big, too tall, or too wide to move. We have to look at the home’s condition and its moveability. A single-story, ranch-style home is the easiest and best to move.”
The company’s website shows homes that are currently available with prices at half of new construction, while also including the delivery cost to the destination. Renewal Development also warranties the structural integrity of the building along with any changed components.
Apart from affordability, this also is a model for more efficient land use, much like repurposing vacant office buildings into housing helps optimize existing urban infrastructure, reducing the need for new land development and promoting more sustainable, compact city growth.
The company’s goal is to replicate this model of repurposing homes across the rest of Canada so that demolition waste doesn’t end up in the landfill, while also advocating to local governments in British Columbia to implement green policies that support density.
Reuse Step By Step
Some U.S. states are taking measures to incentivize circularity and reuse in the construction industry. For example, Buy Clean California gives limits for companies bidding on publicly funded building projects that cap the emissions on certain building materials like concrete, steel and gas.
The city of San Francisco has municipal level standards that state that building products have to have environmental product declarations, or a transparent, objective report that communicates what a product is made of and how it impacts the environment.
Trends often work across the U.S. from California, and with the country’s mounting housing shortages, reuse will become a more and more attractive option. I will be encouraged to see more options for smart, strategic reuse projects that help provide more affordable housing, and at the same time, reduce emissions–a solid win-win.
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