This radical redesign of a door by Austrian artist Klemens Torggler uses a folding and pivoting system to collapse and roll to one side.
Instead of a single panel attached to a frame by two hinges, Torggler's Evolution Door folds into four triangular sections that collapse in on themselves and turn round before straightening back up into a rectangle.
Two halves of the door are attached by pivots at the bottom and top of the frame and a hinge in the middle.
By gently pulling at the joint that connects the two middle panels together, the door folds and slides across the entrance.
"The special construction makes it possible to move the door sideways without the use of tracks," explained Torggler. "This technical trick opens up new applications for the door."
Torggler calls the system Drehplattentür, which translates as the "flip panel door". The artist, based in Vienna, has been working on the concept for a number of years with a series of distinct iterations.
His earliest designs used two metal rods to connect two square panels that would separate then converge in one motion. He developed a second technique that used a cut-out epitrochoid curve with a wheel track that allowed the two panels to move more fluidly than his previous design. The triangular design is his latest.
Torggler has experimented with glass, wood and metal, as well as creating larger double doors and screens to separate entire rooms.
Currently the Evolution Door is a prototype, however a selection of his earlier versions have been made available through website Artelier Contemporary.