When students from Washington University in St. Louis embarked on creating an energy-efficient home for this year’s Solar Decathlon, they chose an unlikely building material: concrete. Aesthetic preferences didn’t drive their decision. Instead, they picked concrete—over materials like wood and metal—because of its ability to withstand tornados, hurricanes, and floods. “We chose it because of its resiliency, which is pertinent now more than ever,” said Adam Goldberg, a graduate architecture student at WashU.

Their dwelling, called CRETE House, is one of 11 prototypes created by collegiate teams for the 2017 Solar Decathlon, the biennial competition and expo organized by the U.S. Department of Energy that aims to prepare students for careers in renewable energy. Multidisciplinary teams from universities in America and abroad are invited to design and build solar-powered homes that range between 600 and 1,000 square feet.