Two First National Plaza - The Skyscraper Center

Facts

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Metrics

Height 124.1 m / 407 ft

Floors 30

Official Name

The current legal building name.

Two First National Plaza

Type

CTBUH collects data on two major types of tall structures: 'Buildings' and 'Telecommunications / Observation Towers.' A 'Building' is a structure where at least 50% of the height is occupied by usable floor area. A 'Telecommunications / Observation Tower' is a structure where less than 50% of the structure's height is occupied by usable floor area. Only 'Buildings' are eligible for the CTBUH 'Tallest Buildings' lists.

Building

Status

Completed

Architecturally Topped Out

Structurally Topped Out

Under Construction

Proposed

On Hold

Never Completed

Vision

Competition Entry

Canceled

Proposed Renovation

Under Renovation

Renovated

Under Demolition

Demolished

Completed, 1973

Country

The CTBUH follows the United Nations's definition of Country, and thus uses the lists and codes established by that organization.

United States

City

The CTBUH follows the United Nations's definition of City, and thus uses the lists and codes established by that organization.

Chicago

Address

20 South Clark Street

Postal Code

60603

Function

A single-function tall building is defined as one where 85% or more of its usable floor area is dedicated to a single usage. Thus a building with 90% office floor area would be said to be an "office" building, irrespective of other minor functions it may also contain.

A mixed-use tall building contains two or more functions (or uses), where each of the functions occupy a significant proportion of the tower's total space. Support areas such as car parks and mechanical plant space do not constitute mixed-use functions. Functions are denoted on CTBUH "Tallest Building" lists in descending order, e.g., "hotel/office" indicates hotel function above office function.

office

Height

Architectural

Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the architectural top of the building, including spires, but not including antennae, signage, flag poles or other functional-technical equipment. This measurement is the most widely utilized and is employed to define the Council on Tall Buildings and Urban Habitat (CTBUH) rankings of the "World's Tallest Buildings."

124.1 m / 407 ft

To Tip

Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest point of the building, irrespective of material or function of the highest element (i.e., including antennae, flagpoles, signage and other functional-technical equipment).

124.1 m / 407 ft

Floors Above Ground

The number of floors above ground should include the ground floor level and be the number of main floors above ground, including any significant mezzanine floors and major mechanical plant floors. Mechanical mezzanines should not be included if they have a significantly smaller floor area than the major floors below. Similarly, mechanical penthouses or plant rooms protruding above the general roof area should not be counted. Note: CTBUH floor counts may differ from published accounts, as it is common in some regions of the world for certain floor levels not to be included (e.g., the level 4, 14, 24, etc. in Hong Kong).

Tower GFA

Tower GFA refers to the total gross floor area within the tower footprint, not including adjoining podiums, connected buildings or other towers within the development.

32,566 m² / 350,538 ft²

CTBUH Member Companies Involved

All Companies Involved

Architect

Design

Usually involved in the front end design, with a "typical" condition being that of a leadership role through either Schematic Design or Design Development, and then a monitoring role through the CD and CA phases.

C.F. Murphy Associates; Perkins+Will

Structural Engineer

Design

The Design Engineer is usually involved in the front end design, typically taking the leadership role in the Schematic Design and Design Development, and then a monitoring role through the CD and CA phases.