City National Plaza

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.

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

That being said, architecture is a complex discipline involving 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

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

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.