A-frames are easily recognized by their triangular shape. That’s the result of lowering the roof and doing away with the walls, says architect Brent Campbell of Asheville, North Carolina.
In “A-Frame,” Chad Randl, an architectural historian and professor at the University of Oregon, writes that A-frames appear throughout history, from ancient Japan to rural Europe. The structures are so strong that snow can slide off the sloping roofs, making them attractive in remote cold regions. Affordable and functional, the A-frame became a popular vacation home style in America in the 1950s. Interest in them persists today.