The project, one of the largest residential geothermal deployments in U.S. history, marks a transformational moment for energy-efficient home construction: Dandelion is bringing affordable geothermal into the mainstream, while Lennar will expand its Colorado presence by 14 communities over the next two years.
Geothermal heat pumps (GHPs) tap into the earth’s stable underground temperatures to deliver highly efficient heating and cooling. According to the Department of Energy, widespread adoption of GHPs could eliminate the need for 24,500 miles of new grid transmission lines—roughly eight cross-country trips.
Until recently, geothermal has been viewed as a premium-priced option for new homeowners. This project will prove that geothermal can scale and deliver massive value to both builders and buyers, according to Dandelion Energy President Kathy Hannun.
Lennar is Colorado’s highest-volume builder. The Dandelion Energy venture will mean a large percentage of the state’s newer homes will use geothermal heat pumps within two years.
“Our collaboration with Dandelion Energy brings innovative geothermal technology into our homes—offering Colorado homeowners a cleaner, more efficient way to heat and cool their homes, while reducing long-term costs and future-proofing their investment,” says Lennar Executive Chairman and co-CEO Stuart Miller. “It supports our broader commitment to making high-quality, attainable housing more accessible.”
The benefits are tangible. For starters, geothermal should lower monthly energy bills by about 17 percent. The Lennar-Dandelion partnership is expected to save homeowners a combined $30 million over the next 20 years when compared to traditional air-source heat pumps.
The savings are by design—literally. Temperatures above ground vary throughout the year, resulting in a need for climate control units such as air conditioners, natural gas- or fossil fuel-powered heaters and HVAC units. In contrast, the temperature just a few feet below ground averages about 55 degrees to 70 degrees Fahrenheit year-round.
In the summer, as outdoor temps rise, a GHP collects unwanted heat in a home and moves it to the cooler earth. On the other hand, ordinary air conditioners dump excess warmth outside, but hot summer air is already saturated with heat. That makes ordinary cooling systems least efficient when needed the most. A similar process happens during cold weather.
The heart of the geothermal system is small-diameter, high-density polyethylene (HDPE) pipes buried underground (a.k.a., a “loop”). The loop circulates earth-heated or cooled water to and from the home.
While large areas such as dorms on a college campus or an auditorium rely upon a community-scale shared loop system, each home in the Lennar-Dandelion project will have its own dedicated geothermal loop. The companies note that single loops mean lower cost, fewer points of failure, and no ongoing operations and maintenance complexity.
What makes this project so groundbreaking (so to speak) isn’t just the technology—it’s the approach.
Dandelion and Lennar have worked together informally in the past, with the former installing systems in several of the latter’s model homes. This triggered interest in geothermal among potential buyers, and this interest was boosted by Colorado’s many electrification-related incentives—including manufacturer rebates, and state and federal geothermal tax credits. The incentives often came as a pleasant surprise to buyers, and ultimately, they offset a home’s higher price tag.
The smaller individual projects led to the realization that community-level efforts could cut prices further. For example, it costs the same to send a drilling rig to one house as it does to send it to a new neighborhood of 10 homes.
The operating cost is split by 10, with the lower expense passed on to the home’s selling price. In such a scenario, geothermal systems to Lennar’s homes can be installed at less than half the cost of installation in a conventional one-off. The overall housing price for single-family homes and townhomes built by Lennar with geothermal will not be much higher than they would with conventional gas furnaces and air conditioners.
That last point will help convince middle-class buyers that installing geothermal is not only affordable for the wealthy. “It’s going to be a real eye opener for a lot of folks to internalize that a builder with the reputation and the cost-conscious profile of Lennar can introduce geothermal into that framework,” notes Dandelion Energy CEO Daniel Yates.
The Lennar-Dandelion Energy project could well be a tipping point for both companies, and for the geothermal industry as a whole. Geothermal could go from niche to norm.
“Lennar is a pragmatic builder,” Hannun notes. “They’re doing this because it makes economic sense for them and their buyers. That kind of stakeholder alignment is what enables scale.”
Lennar agrees. “We forge strong relationships with forward-thinking companies that share our core values,” the company notes. “Investing our capital and our business enables us to drive financial growth and a better, more-sustainable future."