It won’t come as a shocker to people who follow green technology and architecture that Team Germany came away with top marks at the Solar Decathlon, a competition that invites universities from around the world to compete to design — and build — the best zero-energy home. What might have surprised even Team Germany was how the public responded to the open-house event.

The Solar Decathlon might be the coolest DOE–sponsored program since they split the atom. And the public definitely bought it. During the portions of the two-week competition that allowed the public to view houses, those 20 houses saw a lot of house guests.

Placing homes on the National Mall that generate as much energy as they consume — homes that tourists and residents alike can freely browse — exposes people to more than a new concept. Walking into the structure makes the possibility real. It’s one thing to watch the fanciful dream take shape on the Discovery Channel, but the experience changes when you walk into the house, tactile and at hand. You imagine where you’d hang your hat.

Photographer Justin Mathews took a look and shared his own experience. The winning design by Team Germany (mostly architecture students from Technische Universität Darmstadt) — a two-story cube covered in photovoltaic panels — is pictured. Read more about the Solar Decathlon entries here.