On a hot day, instead of cranking up the air conditioning, this house transforms: A screen and shell move out to wrap around the entire home, shading everything so it cools down.

“It provides this flexible control over heat gain from sunlight,” says architect Todd Fix, who compares the screen and shell to extra layers of clothes you can put on or take off. “So if it’s a cold day, the sensor will sense that, and it will close both to keep the heat inside. If you want more light in the space, you can open up the screen or open up the shell.”

It’s a way to create a passive, zero-energy home without the typical passive house design. “The living area is all glass, from the walls and ceiling to the floors,” Fix says. “This opens up a house. Instead of having really thick, insulated walls that are opaque, so you can’t see out or see in, it kind of opens you up to the environment.”

The house, called the Motus, is a concept now, but the designers hope to build it in natural settings, so when the screens are open you’d be surrounded by the ocean or trees. “You get something that’s a more interesting, more wonderful environment,” he says. Being in an all-glass house also dramatically cuts the amount of electricity needed, since it’s filled with natural light during the day. It can run completely off the grid.

A row of solar panels powers the house and can also power the screens as they automatically open and close. Despite their giant size, they’re lightweight, and it’s also possible to open them by hand. “You’re not lifting anything–it’s a linear track that’s horizontal,” Fix says. “So it doesn’t take much power to move it.”

Underneath the house, a “microclimate pool” cools the house by evaporation. If the house is built on the beach, it will have a custom slide inside that leads directly down to the sand.

It all sounds lovely, but that loveliness doesn’t be cheap: Construction costs are estimated at $2.5 to $5 million, which, even with all those energy savings, will take a long time to pay off.