SOM's proposed Diagonal Tower, prominently located Seoul, South Korea's Yongsan International Business District, is a clever, energy-sipping design with expansive, bright interiors. The diagrid shape is the key to the tower's success, allowing winds to slip by and providing multiple faces to protect itself from summer sun while maximizing heat gain during the long winters. The slinky tower’s use of advanced energy-saving technologies throughout actually improves the quality of life for its occupants, making a convincing case that green is not just about saving money and energy.
At first glance SOM looks to be channeling Norman Foster’s Hearst Tower with the strong diagonal frame, giving the building its charatertisic shape. And just like Hearst Tower, the structure’s material is reduced by 25 percent over conventional box frames — something that really adds up in a 64-story tower.
The design takes a few important steps forward in energy savings, both inside and out. Each section is clad in louvers set either vertically, diagonally or horizontally to block summer sun’s glare and heat, but to allow winter solar energy to help heat the interior. The windows are triple-glazed — an unusual choice for large buildings but very important for those seated near widows to maintain comfort.
Chilled beams warm and cool the floors much more efficiently than forced air, and like the windows, they control radiant temperature. The unique design allowed SOM to place all of the supports on the corners, thus providing an immense column-free lobby, adding impressive views throughout the building at street level.