Correction: An earlier version of this article about the Solar Decathlon incorrectly said that the Middlebury College house did not have space for a TV set. There was a television in the living room. This version has been corrected.

The University of Maryland's entry in the Solar Decathlon has plants growing on the roof to keep the house cooler in the summer and to slow rainwater runoff. (Bill O'Leary/THE WASHINGTON POST)

On you mark! Get set! Go build a house of the future! That’s what 19 teams of college students did recently as part of the Solar Decathlon going on now through Sunday at West Potomac Park in the District. The teams were challenged to make a house that’s nice, not too expensive and, most important, uses solar energy. That means that all the houses have solar panels on their roofs in order to capture the energy of the sun and use it to do such things as cook dinner and heat the water for your shower.

The teams had two years to design their homes but only a week to set them up and get them running complete with working faucets and lights, to be judged and toured. (The overall winner will be announced Saturday.) KidsPost took a look at some of the interesting aspects of the houses for you to check out if you go.

What is that growing on the roof? That is what’s called a green roof. Plants on the roof serve as a kind of shade for the house created by the University of Maryland’s team. The plants help lower the temperature inside on a hot day.

Rain catcher: The deck outside the Team China house is designed to catch and filter rainwater that can then be used in the house to do things such as wash your dirty dishes.

Where does the rest of the ice cream go? Notice the small refrigerator in the Team Florida house, designed by students at four Florida colleges. Do you think that’s big enough for your family? It’s pretty small. That means there’s less room to overstock on food that could be wasted.

Space saver: Students at the City College of New York designed their house to go on top of another building. Why do you think they did that? Because it’s crowded in New York City, and space is limited.

That’s a house? The puffy, white vinyl on the outside of the oddly shaped house is called insulation, something that helps keep a house cool in the summer and warm in the winter. Most houses have insulation on the inside, behind the walls, where you can’t see it. By putting the insulation on the outside of the house, the team from the Southern California Institute of Architecture and the California Institute of Technology saved time. Not to mention, the house looks so weird that it’s sure to grab the judges attention!

House and garden: Plant pots are a part of the house designed by the team from Parsons the New School for Design and Stevens Institute of Technology so that occupants can grow their own food.

Breathing wall: In the main living area of the house created by a Purdue University team is something called a biowall, where plants grow out of the wall. You may have learned in science that plants absorb carbon dioxide and release oxygen. Since we breathe out carbon dioxide and breathe in oxygen, plants are good for us! Plus, the biowall looks really cool.

— Moira E. McLaughlin