Inside the First Dual-Certified Zero-Carbon, Zero-Energy Home in the US
It was the summer of 2018. And inside the Javits Center in New York City, Barry Yoakum sat alongside his wife Kathy at the AIA Conference on Architecture.
The pair was listening intently to Julie Snow, FAIA, and Angela Brooks, FAIA, as they told the stories of some of the most innovative architecture projects throughout the US that had successfully merged high design with sustainability performance. Little did they know that one sentence delivered during that session would change their lives and the trajectory of Barry’s architecture firm archimania.
“During that presentation, they made a comment––it was almost like a challenge, though I don’t think they meant it like that––that all of the COTE Award winners, for the most part, were from the coasts––the East and the West Coasts,” Barry said. “So, we said, ‘We need more representation.’”
That “call to action” was all Barry needed to hear. It was game on.
The pursuit of a challenge
Barry and Kathy had recently started the design process for what would soon become their new family home. It was to be situated on a special plot of land in Harbor Town, a neighborhood in Memphis, TN that sits on Mud Island, a small peninsula bordering the Mississippi River. But during that presentation, a lightbulb went off––why not pursue a COTE Award?
And that’s where the pursuit began. They would design a home that would meet the COTE criteria for design aesthetics and sustainability performance. But along the way, Barry and the team at archimania decided to up the ante.
Though the team had already joined the AIA 2030 Commitment to achieve carbon neutrality by 2030, they realized they had a tremendous opportunity before them and they opted to take full advantage. That opportunity was to see if they could achieve zero emissions a full decade early––and do it cost effectively. If the plan worked, they’d have a case study that could potentially help others. But it didn’t end there.
“We were introduced to International Living Future Institute and we said, ‘Let’s go for that!’,” Barry said.
Despite the rigor of the International Living Future Insitute’s (ILFI) “Living Building Challenge”, the team at archimania liked the fact that it went a step beyond self-reporting––it required testing from an impartial third party.
“It was very rigorous,” he said. “It was a lot of sleepless nights.”
Part of what added to those sleepless nights was the precision required in the design and construction of Civitas. To meet sustainability requirements and stay on budget, the team used several prefabricated materials like cross laminated timber (CLT) and structural insulated panels (SIPs)––and that meant tight tolerances, a slim margin for error and some experimentation.
Adding to the complexity, they wanted to stay true to their commitment to high craft. That required rigorously editing materials and any unnecessary elements out of the design equation.
“Part of our work is about craft. Not about perfection, but craft,” Barry said. “And creating what I call ‘zero details’––how do you make things go away, and cost effectively? That’s the hard part.”
Truth and simplicity of materials
Though truth and simplicity in the use of materials already seemed to be embedded in the archimania ethos, they also now had to be very diligent about the carbon footprint and the chemical makeup of every detail.
From day one, a major goal for Civitas was to be “no VOC” (volatile organic compound). To achieve that, the team had to consider the composition of every material used, from the cladding down to the sealants, adhesives and coatings. By keeping materials as true to their origin as possible, it helped simplify the process
Though only a few primary ingredients––laminated plywood, corrugated metal, aluminum, polished concrete, ash wood, drywall, and CLT––went into the making of Civitas, there is still a high level of craft at nearly every turn. And this attention to craftsmanship creates was Barry calls “moments”––Easter eggs that surprise and delight once they’re discovered
In addition to craftsmanship, layers also played a central role in achieving zero carbon, zero energy on a budget.
“Layers for an envelope I like a lot because it protects,” Barry said. “Layers inside of a space, we don’t like that so much. It’s about simplicity, which lowers costs.”
Sustainability down to the studs
To achieve carbon neutrality, Barry and the team at archimania had to blaze a lot of new trails. They tested a different way of pouring concrete slabs to reduce heat flow, became the first use case of CLT in the region, discovered how to geothermally heat and cool the home while working around the limitations of the below aquifer, and engineered moveable, exterior scrims to shade the home.
“This [the moveable scrims] expresses the whole value of zero energy, zero carbon,” Barry said. “It’s this passive moment that started my whole career. These are really effective. They’re not just for show. It’s real effective passive design. And in a moment, you can change them.”
Being able to move the scrims checked several boxes for Barry and the team. From an aesthetic standpoint, it allows the facade to shapeshift, giving Barry the kinetic, playful home he was after. But from a practical standpoint, daylighting can controlled as the sun moves throughout the day. They were also fabricated with a tighter weave at the top to help knock out the sunlight.
Beyond the scrims, Civitas also makes use of solar panels, a Tesla Powerwall, bioswales to capture rainwater, and geothermal for heating and cooling. There are several other passive features sprinkled throughout the home. For instance, on the first floor, there’s a dogtrot––a common feature of historic homes in the South––that allows for airflow through the home and serves as a nod to history.
So, did Barry and the archimaniacs achieve their goal?
They did indeed. Not only did Civitas become the first dual-certified, zero-carbon, zero-energy home in the US, archimania also achieved the 2030 Commitment a full decade early, and in 2021, they earned an AIA COTE Top Ten Award. But more importantly, they proved it could be done and now Barry is committed to encouraging others to do the same.
“I challenge, and say, ‘Do it for yourselves. Do one project. Invest your time and show how it can be a zero-carbon, zero-energy project,’” he said. “It’s the carbon that’s the hard one. But we proved you can do it. Now we need more leaders to go out and do it. This industry has got to do it.”