Made famous in the United Kingdom, wavy walls have also been spread abroad , particularly to the United States. So-called crankle garden walls (don’t you just love it ?) are very cost effective, they end up utilizing less bricks than straight walls.
Your first immediate response was certainly just like ours: it doesn’t make any kind of sense! Well, the wavy walls end up utilizing lesser bricks, because they could be one brick thin. Straight walls would crumble if you rendered them one brick thick. In the meantime, all the curves in the wall give it steadiness.
Wavy walls, aka crinkle crankle walls, have many names, most of which would appeal to Draco Malfoy. They are also known as kinkum crankum walls. Wavy walls were used in England in the 18th century to cultivate fruit. That’s why back then they were usually built east to west, so that one side would always be facing south to catch the sun’s warming rays.