These solar-powered homes push the limits of sustainable living

Since 2002, the U.S. Department of Energy has hosted the Solar Decathlon, a collegiate international competition that challenges students to build full-size, solar-powered houses. As the residential solar industry matures, with constant innovation in home batteries, energy-generating roofs, and more, the competition is as relevant as ever.

The biennial event returned this month and was held in Denver, Colorado, where designs from nearly a dozen teams around the U.S. and abroad were put to the test—well, tests. True to its name, the decathlon involves 10 different contests that score entries on everything from design and engineering to livability and market potential.

After over nine days of competition, an overall winner emerged: The Swiss Team, which comprises students from École Polytechnique Fédérale de Lausanne, School of Engineering and Architecture Fribourg, Geneva University of Art and Design, and the University of Fribourg.

Their house, called NeighborHub, is a community dwelling with multifunctional spaces that can host meals, meetings, workshops, a local market, and more. This focus on flexibility is not only seen indoors, where spaces are reconfigurable with movable furniture, but also on the exterior, which has operable walls and supports solar panels, aquaponics, plants, and a solar food dryer. The house, which got a perfect score of 100 in the Engineering test, features a green roof and two vertical greenhouses.

In second place is the University of Maryland, followed by the team of University of California, Berkeley, and University of Denver. Take a look at their houses, as well as the rest of the entries below (in no particular order). Head over to the official Solar Decathlon website for scores, details, and more photos of each house.

University of Maryland

Serving up a bit of Eichler style with that central courtyard, the reACT house proposes a modular design concept where living spaces can be added according to new needs and energy, water, and food systems come together as “a kit of parts.” The house features a composting system, hydroponic garden, vegetable garden, and movable “living walls” covered in plants.

University of California, Berkeley, and University of Denver

Designed to turn Richmond, California’s urban infill lots into dense, sustainable housing, the RISE house can stack to comprise three stories and five different units. Three of the facades have a slatted wooden design, while the fourth sports a green wall of moss that helps to purify the air.

University of Nevada, Las Vegas

Sinatra Living is a project targeting emptt nesters looking to retire in Las Vegas. Coming in second in the Engineering contest, the design has an open layout, slip-resistant flooring, fall detection sensors, handicapped accessible features, and a home automation system with Amazon Alexa integration.

Missouri University of Science and Technology

SILO, short for Smart Innovative Living Oasis, is a modern, net-zero take on the traditional farmhouse, also aimed at empty nesters. Highlights include home automation and voice control, plus greywater treatment and rainwater collection systems.

Netherlands: HU University of Applied Science Utrecht

Inspired by Legos, Selficient features a modular design with panels that can be expanded or scaled down. The “Internet of Things” is also alive here, where the heat and water systems can all be controlled from a smartphone.

Northwestern University

Designed for Chicago’s baby boomer population, the Enable house has an airy open-plan interior with movable interior walls, plus a sunroom. Air filtering is a big focus here, as the house includes an indoor air quality monitoring system, houseplants, and energy recovery ventilation system.

Team Alabama: University of Alabama at Birmingham and Calhoun Community College

Inspired by Southern vernacular architecture, Team Alabama’s surviv(aL) House is designed to withstand frequent tornados in the state. At the center of the concept is a safe room with tornado panels that will remain intact even if the exterior components are destroyed.

Team Daytona: Embry-Riddle Aeronautical University and Daytona State College

BEACH House is another design intended for retirees. The design incorporates ADA compliant features, a hydroponic garden, and rainwater collection.

University of California, Davis

Built from trees killed in the California drought, Our H2Ouse uses 50 percent less potable water than the average American home. There is a sophisticated greywater system, along with LED displays at each faucet for monitoring water use.

Washington University-St. Louis

The CRETE house makes the case for concrete dwellings, specifically precast insulated panels. Four large gutters protrude from the main structure, providing shade while collecting rainwater and growing plants.