Net Zero Carbon Homes are Here

Are net zero carbon homes a pipe dream?  Not according to the CEO of Thrive, one of the nation’s leading green home builders. Here’s how they’re making net zero carbon homes a reality.

Last week, I attended the EEBA conference—always a great place to connect with like-minded, mission driven building professionals who care about enhancing the sustainability of the built environment.

In years past, EEBA conferencegoers included hard-core greenies (like myself), and the sessions focused mostly on high performance homes and building science best practices. 

This year was different. Not only was there a noticeably larger contingent of production builders from companies like Pulte, Beazer, DR Horton, and Woodside, but also the tenor of the dialogue changed—nearly every conversation I had (or overheard) was focused on net zero carbon.

Why Net Zero Carbon Homes Are Key

During the conference, I had the opportunity to share a stage with Thrive Home Builders CEO Stephen Myers, with whom we just completed the VISION House Sonders, one of the nation’s first net zero carbon demonstration projects located in Fort Collins, Colorado.

In that project, we were able to achieve carbon neutrality with a blend of thoughtful product specification; deployment of sustainable design, building science and green building best practices; and the purchase of carbon offsets.

As for my part of the session, I presented Green Builder Media’s COGNITION Smart Data about why net zero carbon homes are essential to meet our climate goals and to satisfy rapidly changing consumer expectations. 

I endeavored to answer a fundamental question: why should we even care about net zero carbon homes?  Beyond the frequently cited Department of Energy stats that homes and buildings in the U.S. account for 40 percent of our nation’s total energy use, 70 percent of electricity use, and 40 percent of total emissions, COGNITION data shows a surprising upsurge in consumer demand for decarbonization across all sectors of our economy. 

I referenced some of my favorite stats, which I have written about recently, including insights from a 3Q23 COGNITION survey revealing that early adopters and first movers (the majority of whom were Millennials and older Gen Zs), have a positive sentiment about decarbonization and will pay more for net zero carbon packaging, vehicles, apparel, and even homes.

A recent COGNITION Smart Data survey shows that consumers believe that decarbonization strategies help companies generate positive brand equity, result in enhanced innovation, create loyal employees and customers, and mitigate risk.

A recent COGNITION Smart Data survey shows that consumers will pay more for decarbonized packaging, vehicles, apparel, and homes.

The majority of these early adopters and first movers believe that companies with strong ESG strategies are more likely to have long-term success than those without, and that companies with strong ESG strategies have higher quality products.

I presented data showing that, in order to decarbonize their lifestyles, these consumers are driving electric cars, increasing the energy efficiency of their homes, and turning their homes all-electric. In fact, in a COGNITION survey from earlier this year, 100% of Gen Zs responded that they want to live in an all-electric home because they think of electrified homes as the Teslas of the housing sector.

I emphasized the urgency of decarbonizing the built environment by referencing the International Energy Agency (IEA) 2023 Net Zero Roadmap, which outlines scenarios to keep the planet under 1.5 degrees Celsius warming. The report highlights the need to double the annual rate of energy efficiency improvements for homes and buildings and dramatically increase the pace of electrification of homes and buildings through the adoption of heat pumps and other advanced technologies.

I made the case (hopefully convincingly) that some builders are answering the call. COGNITION data shows that over 75% of green builders are optimistic about the long-term prospects of the housing market, largely because they believe that Inflation Reduction Act (IRA) funding will have a positive impact on their business by pulling through energy efficiency upgrades and electrification technologies. 

These builders indicate that they plan to use IRA incentives to install heat pumps, solar systems, induction cooktops, energy management systems, EV chargers, and high-performance insulation, windows, doors, and building envelope systems in their projects.

After I finished my monologue about why we need to build net zero carbon homes, Stephen took the stage to talk about we can do so. As unassuming as he is intelligent, with a sharp, dry wit, it’s not difficult to understand why he is CEO of one of the nation’s greenest home building companies.

Stephen was honest and direct. Using the VISION House Sonders as the use case, he talked about the difference between net zero operational carbon, which he describes as net zero energy + electrification, and net zero embedded carbon, which measures and reduces embedded carbon through careful product selection and carbon offsets.

“If you already know how to do net zero, eliminating operational carbon footprint is straightforward…you just make sure there are zero fossil fuels in the house,” Stephen asserted. “But embedded carbon? That’s more challenging.”

He described the painstaking process of figuring out exactly what was in the VISION House Sonders project. “When we bid jobs, the per-square-foot bidding hides the bill of materials. We bid the entire job, not each component that goes into the job, which makes tracking the embodied carbon and Environmental Product Declarations (EPDs) for products incredibly difficult.” 

He talked about the complexity of making product substitutions to lower embodied carbon. “Product substitutions may be the same specification with respect to performance, but they may have a drastically different carbon footprint.”

Stephen referenced the bill of materials for the VISION House Sonder project, which included 19,436 product inputs and 443 SKUs. In order to determine the carbon footprint of the home, two different calculation databases were used. The results from the two calculators were dramatically different: one showed that the home produced 50 metric tons of carbon a year and the other measured 103 metric tons. 

“Ultimately, we chose the model we felt had the most comprehensive set of assumptions to help us fill in where we can’t get EPDs,” Stephen said. Then, Thrive purchased carbon offsets accordingly in order to reach net zero carbon.

The Takeaways

According to Stephen, when considering a net zero carbon home, it’s important to weigh the options. “On one hand, there is embedded carbon reduction, which may require product and material substitution, which is sometimes easy but often difficult. Maybe niche sustainable products exist, but you have to figure out how well they scale for you. 

You also have to ask how good the EPDs are. On the other hand, there are carbon offsets. If you’ve done the work to calculate embedded carbon, then the offset is easy.”

“The problem with offsets, however, is that they may facilitate greenwashing. If you buy a lot of carbon offsets, you can make a home that isn’t particularly green carbon neutral, and that doesn’t help anyone.” Stephen insists.

He also pointed out that there is a big difference between high and low quality carbon offsets, and that most carbon offset projects are global, not national. He lamented that most of the offsets purchased for the VISION House Sonders came from international rather than U.S.-based projects,.

Stephen admitted that Thrive is at the beginning of its net zero carbon home journey, and the company still has a lot to learn. But he asserted that local governments are tremendously interested in working with builders and other stakeholders to decarbonize homes and buildings, offering ideas, incentives, and collaborations to expedite the process.

“Doing something is better than doing nothing,” he advised the audience. “You have to start somewhere, so don’t get lost in the complexity.”  

He did call on manufacturers to speed up the process by creating EPDs for their products, as well as certification bodies to create standardization throughout the industry. 

No doubt, the process of creating a net zero carbon home is, for now, intricate at best. But just like green building has evolved over the years, so too will decarbonizing the built environment, and the more builders like Thrive pave the way, the less opaque the process will become.