F5 Tower

The F5 Tower is a Contemporary skyscraper designed between 2007 and 2008 by Zimmer Gunsul Frasca, and built between 2014 and 2017, for a reported $450 million dollars, in Seattle, WA.

Its precise street address is 801 5th Avenue, Seattle, WA. You can also find it on the map here.

The F5 Tower has received multiple architecture awards for its architectural design since 2017. The following is a list of such prizes and awards:

• Skyline Awards in 2019
• MICHELIN Key Award in 2024
• SC Awards in 2024

Some reports indicate that the structural height is 201m; however, the elevation plans show that the height varies from 197m at the main entrance on Fifth Avenue to 207m along Columbia Street, due to the lower elevations exposed above sea level..

Zimmer Gunsul Frasca 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 F5 Tower a reality:

• Coughlin Porter Lundeen in charge of Structural Engineering
• JTM Construction as the Main Contractor
• Kone as the company in charge of the elevators system
• Daniels Real Estate as the Main Developer
• SYSKA Hennessy Group in charge of MEP Engineering
• Philippe Starck in charge of Interior Design

The F5 Tower can be categorized as a Contemporary building.

By today's standards the F5 Tower could probably be classified as a "deconstructivism" or "expresionism" building. Only time will tell if any of these substyles will grow and stick onto the history books, or if perhaps it will become a substyle of a larger style. Only time will tell. Until then, we believe it's best to refer to the F5 Tower as a contemporary building.

The F5 Tower uses a trussed tube-in-tube structure , with steel columns and poured concrete over metal decking slabs.

A trussed 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 employs a non-load bearing curtain wall system. This means the curtain wall modules are anchored to the building's structural frame at the edges of the floor slabs. The perimeter columns are set back slightly from the facade, allowing them to remain independent of the curtain wall system.

This configuration enables a completely free design of the curtain wall, unencumbered by structural elements, thus providing greater flexibility in aesthetic choices and maximizing the visual impact of the exterior.

The exterior steel beams serve as reinforcement for the tower, considering its seismic resistance. The tower is engineered to withstand a quake registering as high as 9.0 on the Richter Scale.

From an aesthetic point of view, the facade features continued blue-tinted glass with 2.9m high windows. This continuous surface is only interrupted by the distinctive zigzag pattern on the facade, which follows the same lines as the steel diagonal trussed that help stabilize the structure just behind it. But the lines visible from the outside are not those steel beams themselves.

At ground level, the four-story high base that's set back from the sidewalk is clad in Italian travertine marble. This material continues into the interior, adorned with bronde panels, creating a connection to the Sanctuary.