Sustainability, Habitat’s mission inspire Solar Decathlon team

From left, Ryan Dick, Thomas Hardy and Nick Honkala assemble a model of Harmony House to be shown at a student research presentation.

The breathtaking winner of last year’s Solar Decathlon was an ultramodern, mostly wooden showplace with a minimalist vibe and series of white, lace-cut UV curtains pulled across the outside.

But could it fit on an infill lot in a Middle Tennessee neighborhood? Could it be duplicated again and again at a reasonable price and by a volunteer workforce? Would families with children love the idea of living in it?

A team of Vanderbilt University and Middle Tennessee State University students say they want to build something that answers “yes” to all of those questions.

Selected last spring for the 2015 Solar Decathlon, the team is partnering with Habitat for Humanity of Greater Nashville to build Harmony House. It’s a 1,000-square-foot, energy efficient, fully solar-powered home likely to be used as a test site for the housing nonprofit after the contest ends.

Tiffany Silverstein

“A lot of Solar Decathlon homes in the past have been these sort of weird, futuristic-looking, fascinating feats of architecture, but nothing that some families would want to live in,” said Tiffany Silverstein, a Vanderbilt sophomore computer engineering and math major. “What we’re trying to do is show that you can have a solar-powered house that you can live in. This can be your home in two or three years, not a hundred years into the future.”

Their project’s scope became clear this week at the team’s first general meeting of the semester. In front of a standing-room-only crowd, student project managers Silverstein and Danny McClanahan – also an engineering major – outlined the mammoth task, starting with recruiting volunteers to work at a Habitat construction site on Sept. 21 for practice.

The U.S Department of Energy’s Solar Decathlon chooses the best proposals from teams of university students and gives the teams two years to complete houses. After Harmony House is built on Vanderbilt’s campus, it will be disassembled and shipped to Irvine, Calif., to be rebuilt for the Oct. 8-18, 2015, competition.

There, judges will choose one of 18 homes with the best total score in 10 categories – basically, the one that’s most affordable, comfortable and passive, meaning it produces as much or more energy than it uses. The winning team receives a trophy, international exposure and the career-launching opportunity of a lifetime.

Passion for sustainability

Solar Decathlon came up early in Andy Wallin’s decision to come to Vanderbilt for his master’s degree in civil engineering and construction management. Sanjiv Gokhale, professor of civil engineering and Director of Graduate Studies in Construction Management, mentioned it when Wallin was merely considering the school.

Andy Wallin

After Wallin completed undergraduate studies at Furman University in Greenville, S.C., he became project coordinator for the nonprofit Community Conservation Corps. Among their projects: Partnering with the local Habitat for Humanity branch to weatherize older homes.

Wallin said his nonprofit had to turn down a partnership for a solar water heater project because it was too expensive. He’s excited to help build a house that will be energy-efficient from the ground up.

“My passion involves sustainability – leaving the world a better place than I found it, for my kids and grandkids,” Wallin said. “The ability to give back to the community with Habitat, make the world a more sustainable place with Solar Decathlon, and practice a trade that will provide me income in the future – they’re all good reasons to get involved with the team.”

The Solar Decathlon launched in 2002. For the next contest, held in 2005, University of Massachusetts at Dartmouth partnered with Habitat for its project. Parsons the New School for Design and Stevens Institute of Technology did the same thing in 2011 for their Empowerhouse project. This year, a team composed of University of Florida, National University of Singapore, and Santa Fe College also is working on a Habitat-approved design for Solar Decathlon.

Despite those prior efforts, the affordable housing nonprofit has no design for a solar-powered home that it’s replicating nationwide or worldwide. A spokesperson with Habitat’s North American headquarters said plans are decided by local affiliates, and some are using solar elements in their homes.

Help from Habitat

Habitat takes all the traditional energy-saving measures it can, said Chip Wilson, senior vice president of construction for Habitat for Humanity of Greater Nashville. As a result, the nonprofit’s houses earn Home Energy Rating System scores in the 60s – meaning they’re about 40 percent more efficient than most homes.

While Wilson will advise on Harmony House, he said, Habitat’s most important role is as a client.

“You have to build a house for somebody,” Wilson said. “We’re willing to help supervise, and we’re bringing the affordable housing element to this. We’re also great at working with semi-skilled labor.”

The goal is to build Harmony House for less than $200,000, said Garrett Rome, graduate student adviser on the project and a master’s candidate in construction management. Among the features are:

  • Solar panels on the roof that provide all the home’s energy.
  • A solar thermal system heating the water.
  • Phase-change material that stores heat during the day and releases it at night in winter.
  • An open, dog trot floor plan that contributes to air flow in summer.

The project is being supervised through the School of Engineering with Gokhale and Ralph Bruce, professor of the practice of electrical engineering, serving as advisers.

Want to help?

Under Solar Decathlon rules, the Harmony House team must raise its own funds to build, construct and ship the house. To contribute to Vanderbilt’s team, click here.


Heidi Hall, (615) 322-6614
On Twitter @VUEngineering