Nathan Kahre was studying microbiology as an undergrad at East Tennessee State when a friend asked for help renovating his house. The experience of taking most of the building down to the studs was transformative. “I did a 180 on my career path because of how much I loved it,” says Kahre, who promptly switched his major to construction management. Now working for a small production builder focused on net-zero-energy homes, he is helping to set the pace for new-home construction.
Kahre’s official title at Thrive Home Builders in Denver is “high-performance and healthy home manager.” But unofficially, "I'm the energy nerd for the company,” says the 26-year-old, who has a master’s in sustainable building design and construction and is a certified HERS rater. “I handle the design specification and implementation of anything related to energy efficiency and indoor air quality.”
Kahre is an important part of the 25-year-old company’s strategy for the future. Thrive built its first net-zero home in 2009, and is one of a handful of production builders in the U.S. focused on such a high level of energy efficiency; this year, all 250 of its production homes will be DOE Zero Energy Ready, certified to the EPA’s Indoor airPLUS program, and built to LEED standards.
On a given day, Kahre might model options for a wall assembly to figure out how to reduce the amount of increasingly expensive lumber without compromising performance, review home rating documentation to ensure compliance, or research new products. A substantial amount of his time is also devoted to training subcontractors on the specialized technologies and techniques required to reach net zero. “It’s been a long-held desire of ours to have his kind of expertise in-house,” says Thrive’s CEO Gene Meyers. “He’s helping with strategic decisions on product development, but also with quality assurance in the field that the homes we build actually meet these standards.”
Working at Thrive gives Kahre a chance to affect how homes are built from the ground level. While studying construction management, he participated in a Tennessee Valley Authority–sponsored internship to identify energy-efficiency upgrades on campus. “I worked on a solar feasibility study, did an audit of their outdoor lighting, and went into every room on campus to check to see if it had an occupancy sensor,” recalls Kahre. “The experience got me to focus and think about how we could build better from the beginning.” After graduating, he decided to delve more deeply into building science through a master’s program at Appalachian State University in North Carolina.
While at Appalachian, Kahre participated in the DOE’s 2016 Race to Zero competition, in which student teams around the country design a net-zero-ready project. Kahre’s team proposed a 40-unit building that would provide affordable housing for workers in the recreation and travel industry in Kitty Hawk, N.C. At the competition, he met Meyers, who offered him a summer internship. Realizing how much of a resource he was by the end of his stint, the company was eager to hire him after graduation. “I joke with my friends that every day is Race to Zero all over again,” says Kahre.
As Kahre thinks about ways to reduce energy usage on a large scale, he believes that water conservation has the potential for great improvements. Beefing up building codes to reduce water use makes a lot of sense to him. “There’s a big relationship between water conservation and energy usage,” he says. “The less water that goes down the drain, the less that has to be heated. A lot of energy is spent pumping water to where it needs to go.”
Building houses that are resilient to hailstorm damage is also on the company’s radar. “Having solar on the roof helps, because the panels are stronger than asphalt shingles,” Kahre notes. The company also uses high-quality asphalt shingles, additional waterproofing, durable cladding materials, and appropriately sized window overhangs to reduce the risk of water damage. Says Kahre: “A high-performance home can be so many things in addition to being energy efficient—it can also be more comfortable and low maintenance.”