Photos: Competition shines at Solar Decathalon

The competitors from the Technische Universitat Darmstadt in Germany have sought to create a house that is not only energy-efficient but is also efficient with interior space.

They have built-in cavities on the floor where home features can be put in, such as speakers, shelves or this hole for a bed.

The school used cutting-edge products like vacuum insulation. There are also materials in the wall that turn from solid to liquid as they are heating, which provides a way to store solar energy.

Credit: Martin LaMonica/News.com