Government - Federal

L’Enfant Plaza East & West Retail Renovations

Located in Washington, DC’s southwest quadrant across from the National Mall and Smithsonian Museums, L’Enfant Plaza is a massive mixed-use, commercial complex of multiple mid-century buildings originally constructed in the 1960’s.  The complex features office/commercial and governmental buildings, a hotel, an underground shopping mall and parking, as well as a major subway station.  The overall complex has been undergoing an extensive renovation and redesign, including the redevelopment of the retail mall as well as the existing L’Enfant Plaza hotel and an office building.  A new 600,000 sf office building will also be constructed in the center of the plaza. 

The retail renovation projects included modernization of the existing underground retail mall, the development of a new glass atrium providing access to the underground retail corridor, and structural strengthening at the promenade and plaza levels to accommodate the future nine-story office building.  The strengthening work for the office building was conducted concurrently with the retail renovation to allow retail operations to continue uninterrupted during construction.

For the strengthening portion of the project, a cost-effective demolition concept was devised involving almost no re-shoring of the existing slab.  New concrete framing was constructed over an existing auditorium occupied by the National Transportation Safety Board (NTSB).  To construct the framing, SK&A assisted the contractor in developing a steel formwork system using new and existing columns for support.  A grid of compression beams was also designed to support the plaza layout and future office building concept.  

The large glass atrium portion of the project is composed of a series of steel moment frames.  Slip-critical bolts at the column-to-beam connection were used to accommodate the contractor’s preference for steel erection.  Additionally, the east stair spans between the promenade and plaza levels, with no posts beneath the landings.

The East and West portions of the renovation were designed and constructed as two separate projects.  The West project received an SEA-MW award in the $15-40 Million Renovation category in February 2015. 

Founder's Square Office Building (675 Randolph Street)

This 13-story, 353,000 sf Class "A" office building is occupied by the Federal Government’s Defense Advanced Research Projects Agency (DARPA) in Arlington, VA.  The building is located within the larger Founder’s Square complex, which is a 5.35-acre, mixed-use development with two office buildings, a residential tower with retail, and structured below-grade parking.  The development is certified at the Gold level under the LEED-ND (Neighborhood Development) pilot program.

Designed to meet the Department of Defense minimum Anti-Terrorism Force Protection (ATFP) standards, the building has an 82-foot secured perimeter and is surrounded by a sizeable lawn separating it from the surrounding buildings within the complex.

Liberty Center North Complex (Ballston Metro Station)

Mixed-use residential/commercial complex, consisting of two office buildings, two residential buildings, street level retail space, and underground parking for 1,988 cars, located at Wilson Boulevard and Quincy Street.

One Liberty Center is a 13-story, 316,000 sf office building and is 100% leased to federal government tenants.  The building is designed to meet GSA ATFP standards and is Energy Star Certified.  The Two Liberty Center office building is a nine-story, 177,000 sf office building featuring two-way post-tensioned flat plate construction with a column-free floor plan.

The development’s high-rise residential components are a 21-story apartment building (280,000 sf) with 11,000 sf of retail, and a 20-story (290,600 sf) condominium building with 9,000 sf street-level retail.  An impressive landscaped/hardscaped plaza serves the entire complex.  The entire development is served by five levels of below-grade parking totaling 750,000 sf.

Constitution Center, D Street, SW

Major renovation and retrofit of the former Department of Transportation headquarters into a Class “A”, LEED Gold office building that exceeds GSA’s current Federal Office Building Standards and meets ISC Security Design Criteria.  Access to the subway is provided through the L’Enfant Plaza station, at D Street, SW.  The existing building was gutted down to its structure, which was salvaged and completely renovated to include replacement of the building façade and reconstruction of all service cores.

Amenity spaces were designed with a basic 30-ft. column grid to align with existing column spacing, with long-span designs considered for future tenant options.  Enhanced physical security measures exceed ISC Level IV, and include progressive collapse mitigation and blast-resistant building envelope, anti-ram barriers along the building perimeter, blast-resistant loading facilities, and common security checkpoints.

The modernized building boasts sweeping views of the city, a fitness facility, 400-seat cafeteria, and a major conference center.  The facility received Mid-Atlantic Construction’s 2010 Project of the Year Award in Renovation/Restoration.

Bureau of Public Debt, Phases I & II

This new headquarters facility for the Bureau of Public Debt, a division of the US Treasury Department, was delivered in two phases.  Phase I is a five-story building and was designed to accommodate future expansion projects and Phase II consists of a four-story building.  The building façades complement the surrounding historic architecture of the existing community through the use of brick cladding, metal paneling, and glass.

Unique structural security features include designs to meet Federal progressive collapse mitigation and blast-resistant design criteria.  The project achieved a LEED Certified rating for sustainable buildings.

Anacostia Naval Air Station, Honor Guard Bachelor Quarters

A four-story military dormitory with drill and dining halls (utilizing architectural exposed steel), and a mechanical building.  The drill hall also included a gymnasium and incorporated bowstring trusses spanning 85 feet.

The floors for the entire project were composed of normal weight concrete over form deck on metal form over steel joist, supported on steel beams.  The roofs are purlins or trusses.  All of the foundations systems are structural slab-on-grade on pile foundations, as the project is along the Anacostia River.

One Liberty Center, Office of Naval Research

Phase 1 of the Liberty Center North complex consists of a 316,000 sf, 13-story office building with five levels of underground parking for 567 cars, topped by a 30,000 sf landscaped/hardscaped plaza.  The building is fully leased to GSA tenants, including the Office of Naval Research and other Department of Defense agencies.

The facility was one of the first to meet the post-9/11 security and ATFP requirements.  The structural design features progressive collapse mitigation, steel jacketed “hardened” garage and lobby columns, a blast resistant facade, floor and roof slabs designed for load reversal, and perimeter security in the form of bollards, benches, and planters designed to resist vehicular threats.  

Tenant fit-out services included the evaluation and reinforcement of slabs to accommodate a data center as well as for large high density file storage systems.  SK&A also evaluated the introduction of numerous core drills.  The building also attained the coveted Energy Star Certification.

U.S. Department of Health & Human Services – Parklawn, 5600 Fishers Lane

Renovation of the Department of Health and Human Services’ Parklawn Building to upgrade the facility into a Class “A”, LEED Platinum-certified office building with industrial loft aesthetics and innovative green features.  

Structural modifications included a 12-story vertical expansion to create a new atrium space.  The new atrium feature consists of a new floor at the main building level, along with new elevator and stair cores situated at the atrium corners, serving each level above the atrium floor.  The atrium is enclosed by a new steel-framed roof with 100-foot spans supporting a 100x100-foot ETFE skylight system.  Four existing elevator cores were demolished, removing off-grid columns that required new slabs as well as column jackets at the affected column bays.

Additional modifications included floor penetrations at existing slabs for new elevator and mechanical shafts, in-fill of existing abandoned shafts, FRP retrofits for the new facade and two-story lobby, and blast hardening at columns and slabs. 

Founder's Square (Ballston Metro Station)

This 5.35 acre mixed-use development includes two office buildings, a residential tower with retail, and structured below-grade parking. Located at 675 Randolph Street in Arlington, VA, the first 13-story, 350,000 sf office building was completed in 2012 and includes a 250,000 sf structured parking garage for 600 cars that resides underneath.  The building is designed to meet Anti-Terrorism Force Protection (ATFP) standards for occupancy by a government agency.  

The 17-story residential tower was completed in 2014.  The 238,000 sf building has 256 units, 9,000 sf of retail, and a 120,000 sf structured parking garage for 272 cars. 

To be completed in 2016, the third building is an additional 20-story, 400,000 sf Class “A” office building.  Located at 4040 Wilson Boulevard, the structure will be the tallest office building in the Arlington corridor.  The development is certified at the Gold level under the LEED-ND (Neighborhood Development) pilot program.

Potomac Center South, 550 12th Street, SW

As part of the renovation and expansion of the Potomac Center building, the southern half of the existing concrete-framed structure was completed as Phase I of two phases.  Potomac Center South houses the U.S. Department of Education and has eight levels above-grade and three levels of parking below.  The existing space totaled approximately 250,000 gsf of occupied area plus 150,000 gsf of below grade parking.  The project also included the addition of 220,000 sf of new office space.

The horizontal expansion added reinforced concrete bays to floors two through eight.  The flat plate design of the expansion was similar to the original structure in order to allow for proper ceiling heights.  The building was also expanded vertically by adding three steel-framed levels above the original roof level, plus a new roof and penthouse, bringing the building to its new size of 11 stories.

The new upper levels were designed of composite steel, using 12-inch deep beams and girders in 20-ft. bays in order to minimize the dead load added to the existing columns and foundations.  Foundations were upgraded using mini-pile underpinning.  The entire facade was replaced and the core re-worked to accommodate new MEP systems. Structural security features were also added to meet tenant and GSA requirements.