A zig-zagging building plan is basically a linear form with multiple angular bends in it, alternating the direction at each bend. It can be shaped like the letters W, Z, N, or M. If the line is primarily curved, the plan should be called a wave instead of a zig-zag.

The plan follows one connected line through alternating angular turns. Letter-like outlines such as W or Z are examples of that connected path, rather than separate requirements.

An open angle has one main bend between two segments. A wave has alternating rounded bends, which distinguishes it from the sharp changes of direction in a zig-zag.