Hyperbolic Paraboloid

This building is in Asheville NC. Most people call it a butterfly roof, but the technical name is a hyperbolic paraboloid.  This building is now a used car lot.  The roof is concrete. 

One of the most beautiful structures ever with a hyperbolic paraboloid roof was the Catalano House near Raleigh NC.  This house was neglected then destroyed years ago.  Check out this great piece of modern design here... Catalano House