LOTTE WORLD TOWER: TECHNICAL REVIEW AND SPECIFICATIONS

The Lotte World Tower is the crown jewel of Seoul's skyline and stands as the tallest building in South Korea and the tallest in the OECD. Rising 554.5 meters (1,819 feet) above the Han River, this supertall skyscraper integrates traditional Korean artistry with cutting-edge engineering to withstand the regions specific seismic and climatic risks.

This technical review analyzes the towers tapered ceramic-inspired geometry, its resilient structural diagrid system, and its high-speed double-deck elevator technology.

ARCHITECTURAL DESIGN AND GEOMETRY

Designed by Kohn Pedersen Fox Associates (KPF), the form of the Lotte World Tower is a modern interpretation of Korean art forms, specifically the curvature of celadon pottery and the fluidity of calligraphy brushes. The tower features a continuous curve that tapers gently from a wide base to a slender, lantern-like spire.

A defining architectural element is the "seam" that runs vertically from the base to the tip. This open joint distinguishes the two halves of the tower and orients the structure toward the old city center. The cross-section changes as the building rises, transforming from a square at the foundation to a circle at the summit. The curtain wall utilizes light-toned glass with external vertical fins that manage solar gain and emphasize the verticality of the structure.

STRUCTURAL ENGINEERING AND SEISMIC RESISTANCE

The structural system is designed to endure extreme environmental conditions, including wind speeds of up to 80 meters per second (typhoon strength) and earthquakes measuring up to magnitude 9.0 on the Richter scale. The primary lateral load-resisting system consists of a massive reinforced concrete core (32 by 32 meters) and eight concrete mega-columns located on the perimeter.

These mega-columns are connected to the core via steel outrigger trusses at three mechanical floor zones (levels 39, 72, and 104). At the very top (floors 107 to 114), a "diagrid" (diagonal grid) structure is employed. This steel lattice supports the lantern-shaped crown without the need for interior columns, reducing weight and providing a stunning, open aesthetic for the observation levels.

FOUNDATION AND MAT SLAB

The Lotte World Tower rests on a granite bedrock foundation, providing a stable base for its 750,000-tonne mass. The foundation utilizes a massive reinforced concrete mat slab, which is 6.5 meters thick.

The pouring of this mat slab was a logistical feat, requiring 5,300 concrete trucks to deliver 80,000 tons of high-strength concrete over a continuous 32-hour period. To control the heat of hydration and prevent thermal cracking in such a thick volume of concrete, sensors were embedded to monitor temperature gradients in real-time, ensuring the structural integrity of the base.

VERTICAL TRANSPORTATION

The tower is serviced by a vertical transportation system supplied by Otis, featuring 30 elevators. The highlight is the "Sky Shuttle" system, which consists of two double-deck elevators that transport passengers to the observation deck.

These elevators hold the record for being the worlds fastest double-deck lifts, traveling at speeds of 10 meters per second (600 meters per minute). They can transport visitors from the basement to the 121st floor in under one minute. The cabs feature "Auto-Damping" technology to detect and counter vibrations, ensuring a smooth ride despite the high velocity and long travel distance.

SUSTAINABILITY AND ENERGY EFFICIENCY (LEED GOLD)

The Lotte World Tower has achieved LEED Gold certification. Its energy strategy takes advantage of its location near the Han River. The building utilizes a "Han River Water" hydrothermal energy system, which uses the temperature difference of the river water to assist in heating and cooling the building, reducing energy consumption significantly compared to air-cooled chillers.

Additionally, the tower incorporates geothermal heat pumps, photovoltaic panels on the podium roof, and wind turbines in the upper mechanical zones. The external vertical fins on the façade are calibrated to block high-angle solar radiation in the summer while admitting low-angle sunlight in the winter.

TECHNICAL DATA SHEET

Official Name: Lotte World Tower
Location: Sincheon-dong, Songpa-gu, Seoul, South Korea
Architect: Kohn Pedersen Fox (KPF)
Structural Engineer: LERA (Leslie E. Robertson Associates)
Completion Year: 2017
Architectural Height: 554.5 meters (1,819 feet)
Floor Count: 123
Foundation: 6.5-meter thick Mat Slab
Elevator Supplier: Otis
Primary Function: Office, Hotel (Signiel Seoul), Residence, Retail

FREQUENTLY ASKED QUESTIONS

Is Lotte World Tower the tallest building in Korea?
Yes, it is the tallest building in South Korea by a significant margin, surpassing the Northeast Asia Trade Tower in Incheon.

What is the glass floor at the top?
The "Seoul Sky" observation deck (floors 117-123) features the Sky Deck on the 118th floor. It held the Guinness World Record for the highest glass-floor observation deck, offering a view straight down 478 meters to the ground.

Is the top of the building open?
The "lantern" structure at the very top consists of a diagrid steel frame. While the observation deck is enclosed in glass, the very tip of the spire is an open-air structure that allows wind to pass through, reducing the wind load.

What is inside the tower?
The tower is a mixed-use vertical city. It contains Prime Grade offices, the Signiel Seoul luxury hotel (floors 76-101), the Signiel Residences (floors 42-71), and podium retail connecting to Lotte World Mall.