Architect Chris Benedict is on a rooftop in the Bushwick area of Brooklyn, New York, explaining to a camera how energy recovery ventilators provide fresh air without losing heat. It’s windy, it has been raining, and everything is soaking wet, but she forges on with her message: decarbonizing our drafty, aging building stock is one of the most critical problems we face. And she’s working with an innovative retrofit model that meets the challenge.
Depending on how you play with the statistics, buildings contribute between a quarter and half of the global greenhouse gas emissions threatening the survival of our species. And most of those emissions come from the world’s biggest cities. In New York City, heating, cooling, cooking, water heating and clothes drying in buildings create about 70% of atmospheric carbon and methane.
We’re beginning to do better with the electrification of vehicles and the ramping up of renewable energy. Adoption of these has already passed the tipping point. Greening these sectors together with solving our buildings predicament would put us on a path to ending about 75% of global emissions.
Unprecedented heat, fires, floods and storms are forcing politicians to declare a climate emergency, and more are turning to the building sector for solutions. U.S. President Joe Biden’s pivotal Inflation Reduction Act is pouring billions into tax incentives for building retrofits. Officials all over North America are announcing bans on natural gas hookups in new buildings. In place of gas-burning furnaces, politicians are talking up electric heat pumps.
In the midst of it all, Benedict and her team are in the spotlight, having partnered with New York State, the city and RiseBoro Community Partnership over many years to refine climate solutions, most recently installing heat pumps and other green technology in nine multi-family buildings in Brooklyn. “Suddenly, I’ve been getting a lot more calls about affordable retrofits, creating lower-carbon, healthy spaces,” Benedict says. “This RiseBoro group alone has another 100 buildings. We’re starting on some more projects of theirs right after these nine, plus a 13-storey seniors’ tower.”
Like Benedict, architects, engineers and builders everywhere are now being asked to decarbonize larger buildings than ever before, with well-proven green technology that much of the public assumes is new. Green building professionals have survived decades-long struggles against industry acceptance, regulatory frameworks, tight budgets, supply chains and, above all, fear of change.
Now that public support for the energy transition is growing, can we take emissions from all buildings to near zero? Can we ramp it up fast, and scale it up large? Absolutely yes, say these experts. Corporate Knights reached out to the teams working on more than half a dozen of the most exciting green architectural achievements in North America to learn more about how they’re doing just that.
There may not be enough of them, but many buildings are already greener than we think, and sustainable features are already operating at large scale. Read on to find out just how large and how today’s green building heroes are trying to save our planet.
Affordable housing retrofits in Brooklyn
The first Earth Day took place on April 22, 1970, and on that mucky spring morning, a young Benedict donned her rubber boots and went out into the woodlands and parks of Connecticut with a community team to pick up litter. She was shocked to discover that, by summer’s end, people had thoughtlessly spread trash in the exact same places.
Now an architect, Benedict is still trying to clean up the neighbourhood. But she’s using Casa Pasiva, a 146-unit project in Bushwick, as a model for healthy, cost-effective, deep energy retrofits to occupied buildings that are mostly affordable rental units. Her team is refining an innovative methodology to reach Passive House certification from Phius (Passive House Institute U.S.). “With retrofits you become inventive,” says Benedict. “We were able to get a zoning change approved so we could put eight inches of insulation on the outside of buildings. We all need to take action and take responsibility for climate change.”
The insulation, along with new windows, heat pumps, induction cooktops and energy recovery systems, will reduce energy usage by 60% to 80%, significantly lowering operational expenses and emissions. Tenants usually grumble about having to move out for a couple of weeks during renovation, but, Benedict says, “when they hear they will be able to control their air conditioning, they’re more motivated.”
It’s relatively easy to erect a few new low-carbon single-family homes or multi-unit structures. Benedict has worked on a number of them. But buildings last for up to 100 years and are typically replaced at a rate of about 3% annually. Most of New York City’s fossil-fuel-heated edifices will still be standing in 2040. Benedict is one of the few people anywhere successfully tackling this massive retrofit challenge – and the impacts are longer-lasting than picking up litter.
Extreme-weather-resilient subdivisions in Florida and Texas
In 2022, Hurricane Ian hit Florida with a huge storm surge and 150-mile-per-hour winds. It killed more than 100 people and left billions of dollars in damages, mostly around Fort Myers. It bashed the area for nine hours, but a town called Babcock Ranch almost completely withstood the pounding. Built among forest trails, lakes and wetlands by former NFL player Syd Kitson, the town of 2,000 homes features extensive ecosystem-based flood and wind defences, plus solar panels, home batteries and electric vehicle chargers.
“When I was a child, my father and I witnessed the incredible power of a hurricane slamming the New Jersey coast,” Kitson says. “The outdoors are in my soul. I wanted to create a place that respected nature and could stand up to hurricanes.”
Babcock civil engineer Amy Wicks agrees. “Nature was always smarter than us. It has survived for thousands of years. We need to work with it, not against it.”
Some of the country’s largest builders are partners at Babcock Ranch, as well as at Whisper Valley, one of several expansive sustainable subdivisions in the Austin area in Texas. The latter will soon reach 3,000 low-energy homes, all cooled and heated with geothermal. The low-carbon system uses artificial intelligence to save about 60% on energy through networking, sharing and optimization.
Whisper Valley is as resilient as Babcock Ranch. The subdivision emerged unscathed from the deadly Texas cold snap of 2021, which killed more than 200 people with lower-quality homes and heating equipment not designed for freezing temperatures.
Geothermal for Toronto condos
For 13 years, Tim Weber tried to sell geothermal cooling and heating systems to Ontario condo developers with little success. Why add to capital budgets with scary technology? Weber hit on an idea: what if, like the gas companies, he became a utility?
He found a deep-pocketed investment partner in Quebec, created an entity to handle condo owner billing and maintenance, then in 2015 he went back to developers with the message that he could now own and maintain those systems, reducing both their capital budgets and technology problems. They started listening. There are now dozens of increasingly large condo projects in Ontario with geothermal fields under them.
One of Weber’s early partners was Stanley Reitsma, who as a teenager planted hundreds of trees on his family farm in Ontario and later studied geology and earth sciences. Reitsma went to work in the Alberta oil sands, drilling deep holes in the ground. “But I was always an environmentalist,” he says. In 2004, he headed back east and started GeoSource Energy.
Today it’s one of the most successful geothermal drillers in North America, bringing geothermal heating and cooling to condos, affordable multi-family homes, and university and government facilities on both sides of the border. The projects are big and the company will soon scale larger, too. Always a little ahead of the curve, Reitsma is now working with some international construction conglomerates interested in creating models that can respond to the current dramatic increase in green construction.
Passive and massive in Boston
Thanks to double pane Sotawall Thermo-3 windows, a howling wind outside was barely audible on the 32nd floor of Boston’s Winthrop Center in January while Brad Mahoney talked about architectural details and energy loss: “This is not just a blip. This is the way that projects will be built.”
Millennium Partners, the developer behind the Winthrop Center, claims that at 53 storeys, the massive 1.8-million-square-foot residential, office and retail complex is “the world’s largest Passive House office building.” More than half of it, the 812,000-square-foot office section, is LEED (Leadership in Energy and Environmental Design) Platinum, WELL Gold, and Passive House certified by PHI. The entire building will emit about 150% less carbon than a typical Class A (modern high-rise) structure and 60% less than LEED Platinum. (LEED was one of the earliest building energy certifications. Passive House is more rigorous, and results-focused. WELL emphasizes health and wellness by managing air quality, water, light and fitness enhancement.)
Before 2016, Millennium was not focused on sustainability. But Mahoney had always been environmentally conscious, having acquired his LEED AP (for “accredited professional”) designation about 20 years ago. He persuaded Millennium’s president that green buildings were the way forward. The two began building a digital library on all things related to low-carbon construction. They partnered with a Massachusetts Institute of Technology professor and visited the Passivhaus Institut in Darmstadt, Germany. They hired New York’s Handel Architects and Steven Winter Associates for the Winthrop Center request for proposal. They won the contract.
Last year, the project won a 2022 Passive House Trailblazer award from the U.S. Passive House Network, and tenants start moving into the tower in early 2023. “This is the space to be in, because there is now so much momentum,” says Mahoney. “We’re never going back to the old way.”
Harlem: ‘Sendero verde’ means ‘green path’
In October 2019, at a low-key technical event at the Scarborough campus of the University of Toronto, the keynote presentation was given by building engineer Lois Arena from Steven Winter Associates and architect Deborah Moelis from Handel Architects. The presentation’s content reverberated across the North American construction world.
The duo was instantly famous, revealing that they had designed the 709-unit Sendero Verde project in New York City within the confines of an affordable housing budget. They reported that their companies had also collaborated on The House, a 26-storey modular Passive House–certified student residence for Cornell University’s tech school on NYC’s Roosevelt Island, and were working on the 53-storey Winthrop Center in Boston. Oh, and by the way, the Passive House–certified residence for U of T Scarborough coming in 2023 is theirs too.
Sendero Verde is perhaps the big daddy of them all. The two-building housing complex in Harlem has double pane windows, a well-sealed envelope at least five times tighter and better insulated than typical buildings, and is heated and cooled by a commercial-scale heat pump system.
Arena and Moelis’s presentation was a shock for many, because it helped answer some of the questions that a significant portion of the construction industry and the rest of the world is only now beginning to ask: Are green buildings a theory, a bunch of pilot projects, or a real thing? Can they be built quickly? Can we afford to build them?
“We’ve got the data now, and all our projects are already at least 50% lower emissions,” says Dylan Martello, Passive House consultant on Sendero Verde. “With New York, Massachusetts and many other governments making changes, I’m optimistic that things are going in the right direction, but I’m not sure if it’s fast enough. I worry because I want to have kids one day.”
Today at building conferences around the globe, the question being asked by Martello and a growing legion of allies is no longer “Can we afford to build green buildings?” It’s “With our planet in crisis, can we afford not to?”
BF Nagy is the author of The Clean Energy Age and numerous magazine features. He also produces videos on climate solutions.
