French company Manufactura designs and builds custom-fit retractable spiral staircases:
"Our staircase allows you to access all the living spaces that your accommodation offers, even the most cramped ones such as a basement apartment, a rooftop or an attic. It unfolds and retracts in seconds. Offers a substantial space saving. Allows you to clear your stairwell to move furniture through."
The company, which holds a patent on the design, customizes each staircase to the specifics of the space.