Butterfly roof

[2] The modern butterfly roof is commonly credited to be the creation of William Krisel and Dan Palmer in the late 1950s in Palm Springs, California.

It has been estimated that starting in 1957, they created nearly 2,000 houses in a series of developments that were popularly known as the Alexander Tract, which has been described by historian Alan Hess as "the largest Modernist housing subdivision in the United States.

They were also commonly used in Georgian and Victorian terraced house architecture of British cities, where they are alternatively termed "London" roofs.

[citation needed] The form has no gutter as rainwater can run off the roof in no more than two locations, at either end of the valley, often into a scupper or downspout.

[3] A large house with a butterfly roof features prominently in the 2009 British TV crime drama trilogy Red Riding as 'Shangri-La', the home of corrupt property developer John Dawson, played by Sean Bean.