Public Sector - Federal

Midtown Center/Fannie Mae HQ

SK&A provided structural engineering services for a new headquarters building for the Federal National Mortgage Association (FNMA), commonly known as Fannie Mae.  The new 875,000 sf Midtown Center office complex is comprised of two 14-story towers, East and West.  The structure features 45,000 sf of retail space, multiple three-story atria, three levels of below-grade parking, as well as a fitness center, rooftop terrace, and private alley.  The project also includes a 15,000 sf public courtyard surrounded by the buildings on three sides and is activated by ground floor retail.

A unique and distinct design feature within the complex are its three interconnecting “tunnel” bridges which span more than 110 feet across the site’s courtyard, connecting the east and west towers at levels 9 through 14.  The bridges feature interior walkways (inside of the bridges) and exterior walkways (on top of the bridges, open to the air).  The bridges were typically designed as “king-post” trusses utilizing heavy W36 section for top chord, eight-inch square tube steel section for bottom chord, and two (2) three-inch diameter high-strength tension rods by “Macalloy” as diagonal members connecting to an eight-inch square tube section vertical steel post, at the center of the bridge.

The three-story, below-grade parking deck uses conventionally reinforced concrete flat slab construction.  The courtyard slab and private alley above the top garage level is designed for landscape and fire truck loads.  The office level structural framing consists of eight-inch, post-tensioned concrete slab with eight-inch-thick drop panels over columns.  This efficient framing system allowed sufficient plenum space for the installation of MEP systems within the ceiling as well as the curtainwall anchors.  The project will pursue LEED Gold certification.  

View photos from a 2017 Site Visit.

U.S. Armed Forces

Public Sector - Federal

– U.S. Air Force 
– U.S. Army Corps of Engineers (USACE)
– U.S. Naval Facilities Engineering Command (NAVFAC)
– U.S. Marine Corps  

U.S. Department of State

Public Sector - Federal

Foreign Embassies and Consulates in Washington, DC
– British Embassy
– Embassy of the Arab Republic of Egypt
– Embassy of Botswana
– Embassy of Finland Chancery
– Embassy of France
– Embassy of Germany
– Embassy of Greece Chancery
– Embassy of the Philippines
– Embassy of Nigeria
– Embassy of Norway
– Royal Embassy of Saudi Arabia
– United Arab Emirates Chancery
– Passport Services

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