As Home Technology Expert on Ask This Old House, Ross Trethewey is responsible for seeking out some of the coolest stories in home technology and bringing them to a national audience.
You could say that Ross has This Old House in his blood. His grandfather Ron served as the plumber on the very first season in 1979, before Ross was even born. His father, Richard, has been known as the face of all things plumbing and HVAC to This Old House fans for four decades. Growing up, Ross remembers accompanying his dad to job sites. He especially remembers the excitement of filming days when show creator Russ Morash and the camera crews were on-site.
“What’s amazing to me is that the geothermal system from 1996 is remarkably similar to the one we put in last year. I guess the apple doesn’t fall far from the tree…my dad and I both find technology like this fascinating, and worth celebrating.” —Ross Trethewey, TOH building engineer, in TOH Magazine, Spring 2024
In a 2014 feature in TOH Magazine, Richard Trethewey appeared with sons Ross and Evan, noting that they “were born with a knack for understanding how things work.” By that time, both were already helping run the family business. As Ross recalled on camera, “Growing up, we would hop on a plane or get in the car — my mother, my brother and I — and we’d drive to wherever the project was. My brother and I would be swinging hammers and banging wood. And when I got a little bit older, I wanted to learn. And so I was trying to pull Tommy away and ask him a question about something.”
The Trethewey family’s roots in the trades run even deeper than the show itself. As Richard Trethewey wrote in TOH Magazine: “My great-grandfather and his brother were firefighters in 1902 when they began moonlighting as apprentices in ‘this new thing called plumbing.'” That legacy — spanning well over a century — makes Ross part of a remarkable multi-generational lineage in the mechanical trades.
Ross has lent his expertise to both This Old House and Ask This Old House since 2011, contributing to stories about renewable energy that looked at solar power, wind power, geothermal, and off-grid storage. He became a regular presence on Ask This Old House in 2016 when he and producer Heath Racela developed Future House, a segment that looks at the impact technology will have on how we build and live in our houses.
In His Own Words: Ross Trethewey describes the segment’s mission: “Future House to me is a sneak peek where we’re taking those technology and products that are really in their infancy and trying to bring them to the audience.”
In addition to his TV duties, Ross founded an engineering design and consulting firm in 2010 and serves as its lead engineer. TE2 Engineering provides building energy analysis, mechanical, electrical and plumbing design, and renewable energy design for clients in both the residential and commercial space. The company’s focus is high-performance HVAC design and integrated smart home design.
Pro Tip: Ross frequently advises homeowners against oversizing their HVAC systems—a common and costly mistake. As he has explained, insisting on a heating system that’s too big “makes the equipment cycle on and off more frequently, which is inefficient and will cause it to wear out faster.” His guidance: “Have your contractor calculate a size for your system that doesn’t go overboard, and trust that a system of this size will keep you comfortable. Because it will.”
Ross earned Bachelor of Science and Master of Science degrees in mechanical engineering from Tufts University in Massachusetts. He is also a professional engineer. Prior to forming his own consulting company, he lived and worked in Germany for a manufacturer that specializes in high-efficiency heating and renewable energy equipment.
Ross’s time in Germany proved formative. His father, Richard Trethewey, has long regarded the country as a global leader in home heating and energy efficiency, visiting for over 30 years and attending events like the International Sanitation and Heating (ISH) Fair in Frankfurt. Richard has called ISH “grand theater,” describing how “manufacturers hire famous designers to develop products, which they sneak into the show under cover of night and unveil with great fanfare.” That deep familiarity with German engineering culture informed Ross’s own career path, giving him firsthand exposure to high-efficiency heating systems, renewable energy technologies, and building performance standards like Germany’s Energy Pass — a report card on every building’s energy use that can influence property values and rental rates.
Ross lives in a rowhouse in Boston with his wife and two young sons. He learned to sail at an early age and loves to spend as much time on the water as possible.
Early Builder: Ross’s passion for hands-on work started young. His brother Evan recalled one of their earliest father-son projects — building a Pinewood Derby car together with their dad Richard. As Evan put it: “Ross and I always felt like when we were doing something like that, because we had Dad, we were going” to have an edge. The competitive spirit and family teamwork that defined those childhood projects clearly carried over to Ross’s career on This Old House.
Follow Ross on Twitter @RossTret and on Instagram at @rosstrethewey.
