Outrigger systems are rigid horizontal structures designed to improve a building s stability and strength by connecting the building core or spine to distant columns, much in the way an outrigger can prevent a canoe from overturning. Outriggers have been used in tall, narrow buildings for nearly 500 years, but the basic design principle dates back centuries.

In the 1980s, as buildings grew taller and more ambitious, outrigger systems eclipsed tubular frames as the most popular structural approach for supertall buildings. Designers embraced properly proportioned core-and-outrigger...