City National Plaza

City National Plaza
  1. About the City National Plaza in Los Angeles
  2. Architect and team
  3. Architectureal style
  4. Spaces and uses
  5. Structure and materials

The City National Plaza is an International Style skyscraper designed in 1969 by Albert C. Martin & Associates and built between 1970 and 1972 in Los Angeles, CA.

City National Plaza is not the only name you might know this building by though. Between 1972 and 2013 it was also known as Arco Center.

Its precise street address is 505-555 South Flower Street, Los Angeles, CA. You can also find it on the map here.

City National Plaza is a complex featuring two 213-meter-tall towers, the City National Tower and the Paul Hastings Tower, along with a single-story plaza level building.

The building has been restored 3 times over the years to ensure its conservation and adaptation to the pass of time. The main restoration works happened in 2004, 2016 and 2018.

Building's timeline

Design completed
Construction begins
Construction completed
years ago
  1. 2004 - The underground mall was remodeled and the lower level converted to parking.
  2. 2015 to 2016 - On the 51st floor of the Pault Hastings Tower, old bronze-tinted glass pieces were replaced with Starphire glass, while on the 52nd floor, some granite blocks were removed and replaced with ultra-clear, low-iron glass panels. These changes enhanced the space for VIP tenants, offering improved views and increased natural light. The architect in charge was G&T.
  3. 2013 to 2018 - Renovation of the lobbies in both towers, which included security systems, double glazing, new ceiling lighting, and elevators. The renovation in the North Tower, the City National Tower, also involved the transformation of a former bank office into a state-of-the-art creative workspace, incorporating the construction of an indoor-outdoor events center.. The architect in charge was Gensler.

Architect and team

Albert C. Martin & Associates was the architecture firm in charge of the architectural design.

Albert C. Martin & Associates was in charge of the architectural design, however, architecture is a complex discipline, which usually involves many professionals from different fields, without whom this building would have not been possible. We will surely be leaving out a lot of names here, but here is a list of the people we do know also played their part in making the City National Plaza a reality:

  • A. C. Martin Partners in charge of Structural Engineering
  • Herbert Bayer, as the collaborating Artist

Architectural Style

The City National Plaza can be categorized as an International Style building.

The international style originated in Europe in the early 20th century, and made its way to the US a couple of decades later when the rise of the Nazi regime forced figures such as Walter Gropius, Marcel Breuer, or Mies van der Rohe to flee Europe.

The International Style emerged as a response to the prevailing historicism and ornate architecture styles of the late 19th century, which according to a younger generation of architects didn't represent the new materials and construction techniques that were on the rise at the time.

Architecture in the early 20th century US was marked by the adoption of steel structures, modern construction techniques, and the rise of the skyscraper. As it turns out, this combination of circumstances created the perfect ecosystem for the International Style to flourish, becoming the to-go style for skyscraper designs during the mid-20th century, when American cities were growing fast.

The International Style’s legacy can not only be found in numerous iconic buildings across all major American cities, but also incorporated in contemporary architecture, which still puts a big emphasis on functionality and minimalism.

Spaces & Uses

The City National Plaza reaches an architectural height of 699ft (213m). It has a total of 56 floors, 52 above ground and 4 basements, served by 32 elevators, which combined offer a total of 2,217,363 sqf (206,000m2) of usable space.

In regards to parking space, the building has a total of 2485 spots available, which roughly equals 48 spots per floor (above ground), or one parking spot per every 893 sqf (83m2) of usable space.

Ever since opening its doors to the public in 1972, the City National Plaza has mainly been used as Commercial space.

699ft (213m)
4 basements

Materials & Structure

The City National Plaza uses a framed tube-in-tube structure , with steel columns and concrete slabs.

A framed tube-in-tube structure uses a central core, known as inner tube, which usually holds stairs, lifts and installations, and a perimeter of columns around it, which form the exterior tube. The interior tube is tipically more massive (often made of reinforced concrete), and the exterior tube is "lighter" (made of steel or concrete columns). Both tubes are conencted via horizontal elements which make up the floors and also transmit any horizontal froces from the facade to the core.

The facade of the building is load bearing. This is a direct consequence of the integration of the exterior "tube" into the facade, something which most framed tube-in-tube buildings do in order to liberate the interior space from structural elements and achieve a more flexible interior.

So the facade of the builing is techinically load-bearing, yes, however, in between the load-bearing colums we find a window-wall type of facade, which by itself would not be cosnidered load-bearing.

From an aesthetic point of view, the facade features polished moss-green granite and dark glass.

The ground level has double the height of regular floors and its facade is retracted, creating a covered outdoor space around the towers that acts as pedestrian walkways and houses several retail shops.