Private Sector

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.

The Liz | Whitman-Walker Health

SK&A provided structural engineering services for the redevelopment of the Whitman-Walker Health Clinic site into “The Liz”, a mixed-use development incorporating new residential, retail, and office spaces.  The project also entailed the renovation and repurposing of the clinic’s existing historic structures located at 1701 and 1711 14th Street, NW.

The preservation of the two historic buildings required significant underpinning and other below-grade modifications to the existing basements.  The new structures are seven stories above-grade with two new below-grade levels.  The residential areas occupy approximately 80,000 gsf (78 luxury apartments) and retail and office spaces are 80,000 gsf.   Retail tenants include Sephora, Bluestone Lane, Amazon and Parachute Home.  The office space houses Whitman-Walker’s new headquarters, encompassing their administrative, legal, public benefits and research departments, as well as offices for Fivesquares Development and the Goethe Institute, a German language school.

The development also includes a 2,800 sf cultural space for community events and art exhibitions focused on the LGBTQ community.  The remaining square footage (approximately 60,000 gsf) consist sof areas for parking, loading and other back-of-house functions.

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