The Watergate EIG Tenant Fit-Out

The Watergate EIG Tenant Fit-Out project involved fitting out levels 11 and 12 of the Watergate office building located at 600 New Hampshire Avenue, NW for EIG Global Energy Partners.  Structurally, SK&A was specifically tasked with creating three new openings in the existing 12th floor post-tensioned slab as well as designing two new inter-connecting stairs.  

The stairs were called the “Patricia” and “Ricardo” internally by the design team, named after the Nixon couple associated with the infamous Watergate scandal.  The Patricia is a single center stringer stair that is wider at the bottom and top than it is in the middle and finished with terrazzo treads.  The Ricardo was the more unique and challenging of the two stairs, using a ½” curved steel plate for the stringer on each side.

Architecturally, the team had very specific aesthetic expressions for each staircase, as can be seen by the specific naming of each, and SK&A met the challenge to ensure that the architectural vision was fully realized.


Constitution Square

Located at First and M Streets, NE, in the vibrant NoMa neighborhood, Constitution Square is a 3.1 million-square-foot, multi-phased, urban mixed-use complex featuring multiple office, residential, hotel, and retail buildings. SK&A was selected to provide structural engineering services for the Class “A”office buildings, Three Constitution Square (OB3) and Four Constitution Square (OB4), as well as Residential Building Two (RB2), a 13-story apartment building.  SK&A also provided special inspection services for construction of a 12-story office building (OB3) over a two-level parking garage.  The construction of the building is a conventionally reinforced slab in the substructure and post-tensioned reinforced slabs in the superstructure levels above. 

Special inspection services were also provided for construction of a 13-story residential building (RB2) over a three-level below grade parking garage.  The substructure of the building (mat foundation, foundation walls, slabs, and columns) consists of conventionally reinforced concrete and the superstructure consists of post-tensioned reinforced concrete slabs above grade.

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.

DC Water Headquarters

SK&A provided structural engineering services for the design of DC Water’s new headquarters. The stylistic, modern facility is located on 2.75 acres, adjacent to the waterfront mixed-use development, The Yards, and the Washington National’s baseball stadium.  

The new building is a six-story, 150,000 gsf steel-frame structure with a fluid form. The building footprint was carefully shaped to develop a unique, site-specific solar response and consists of full-height curtainwall on the south, east, and west sides to take advantage of the scenic views, and gradually shifts to punched windows on the less scenic north side of the building.  The structure consists of a framed concrete slab-at-grade with six levels (five office levels and an accessible roof terrace) of composite steel construction.

The exterior facades feature a glass and aluminum curtain wall system on the south facade, and a “variegated green rainscreen panel system” on the north and west facades.  The building was constructed around and above the existing “O” Street Pumping Station, which maintained full operations throughout construction.  Foundations for the structure consists of below grade transfer elements and deep foundations.  As part of the landscape design, an exterior boardwalk and metal grating structure was implemented over existing tidal gates.

New mechanical equipment support and an enclosure were added on top of the existing pump station building.  New openings in the exterior walls at the ground floor  of the pump station facility provide a visual connection to the pump room from the new lobby.

Additional project features include an entry court, interactive exhibit space, and a boardwalk along the south facade.  The mechanical systems uses the pump station wastewater for heat recovery and rainwater from the rooftop will be collected in a cistern to use for toilet flushing.

The Watergate Complex Plaza Repairs

The Watergate Complex in Washington, DC includes a hotel, office building, condominiums, and retail.  SK&A’s Repair & Restoration Division provided repairs to the office building’s B-2 level retail plaza area and B-3 level parking garage directly beneath the plaza.  The B-2 level retail plaza area is leased by Penzance and the B-3 level below is owned by Watergate East, Inc. and consists of residential parking, tenant storage rooms, various hallways, and mechanical rooms.

The original waterproofing on the structural slab located below the exterior plaza topping slab is a continuous coal tar fluid-applied waterproofing system, which at the time of the repair was approximately 43 years in age.  Over the years, the original waterproofing has been exposed in isolated areas throughout the plaza, and removed and replaced with either sheet membranes or hot fluid-applied rubberized asphalt systems.

In 2012, SK&A provided construction documents and specifications related to the concrete repairs and waterproofing design for the B-2 level retail plaza and B-3 level garage.  The work was performed from December 2012 to May of 2013 and consisted of the removal and replacement of the exposed aggregate topping slab located throughout the B-2 level plaza within the retail mall area.  Once the topping was removed, the existing waterproofing was removed and replaced and concrete repairs were also performed to the underlying waffle slab.  An existing two to four inch thick decorative concrete topping was replaced in the center of the plaza with a new black, gray, and white alternating colored Miracote coating.  New waterproofing details were provided at drains and along the plaza perimeter in order to provide tie-ins and terminations, as well as to aide in drainage of the plaza.  The repairs involved daily coordination between the contractor and management in order to complete the work and maintain daily access to each individual retail store impacted by the work.  

Crystal Square Complex Parking Garage Repairs

The Crystal Square Complex in Arlington, Virginia consists of four office buildings and an apartment building bordered by Crystal Drive, 18th Street, 15th Street, and Jefferson Davis Highway in Crystal City.  The five high-rise structures sit atop three levels of subterranean parking used by the residential and commercial entities.  The upper two tiers of parking (G-2 and G-3 Levels) consists of one-way joist slab, flat slab construction, and post-tensioned normal weight concrete slabs with the lowest level (G-4) being a slab-on-grade.

SK&A performed a phased comprehensive condition appraisal of the garage complex that included a delamination survey and preparation of repair budget estimates.  Upon completion of each phase of the garage assessment, SK&A prepared repair construction documents pursuant to the cost budget and scope of repairs authorized by the owner.  SK&A’s construction documents detailed the requirements for the phasing of each of the five building garage sections, and for constructing the structural, MEP, architectural, and waterproofing repairs to the garage.  The documents consisted of drawings and specifications that included the quality level of materials and systems required for the repair program.  Bids were solicited on the Owner’s behalf and SK&A reviewed the received bids and provided recommendations for an award.  

Transpotomac Canal Center Plaza, Garage, and Canal Lock Assessment and Renovations

SK&A was authorized by American Real Estate Partners (AREP) to proceed with an observation of the building structure, plaza, canal lock, and subterranean parking facility of the buildings comprising the Transpotomac Canal Center at 1119 North Fairfax Drive in Alexandria, VA.  The site contains four 10-story, Class-A office buildings, constructed in 1986, and originally designed by SK&A.  The survey performed by SK&A was limited to the structural features, waterproofing materials, the historic mouth fountain and canal lock, and architectural construction features.  Items related to civil engineering, ADA compliance, and mechanical, electrical & plumbing (MEP) infrastructure were evaluated by consultants under contract with the owner.

Based upon our visual observations and assessment, we found the building structure to be in good condition while the parking decks and plaza wearing surface are undergoing moderate to severe physical distress.  The major problem conditions noted during the survey areas are follows: water infiltration into the below grade structure, water infiltration through the plaza roof, leaks into the garage through the historic mouth fountain, seepage of ground water through the mat foundation slab, and extensive spalling of concrete in the parking deck slabs.  The observed deficiencies posed an imminent threat to the safe operations of the facility.  As such, the owners implemented SK&A’s recommendation, which is to move forward with a comprehensive plaza and parking garage restoration project beginning in year one of a ten year deferred maintenance program developed by SK&A.  

With respect to the garage and Canal Lock repair program, SK&A was the sole consultant spearheading the design, bidding, and construction administration efforts.  SK&A provided waterproofing and structural design services needed to restore the structural integrity of the parking facility.  The design featured the removal of all deteriorated concrete, corrosion inhibiting treatment, replacing expansion joint seals, and application of traffic membrane over the suspended parking decks.  Leaking cracks in the exterior foundation walls were injected with a hydrophilic grout and sealed from the interior.  

Inglewood Portfolio Roof Replacement Projects

SK&A provided roof replacement services for the Inglewood Portfolio in Largo, MD.  The portfolio consists of five commercial office buildings located at 9200 Basil Court, 1801 McCormick Drive, 9301 Peppercorn Place, 1441 McCormick Drive, and 1221 Caraway Court.  The buildings range from one to five stories with structural steel framing and exterior masonry façades.  Roof replacements and modifications were made to all four buildings, as follows:

  • The 9200 Basil Court building consists of three roof levels on the third floor, upper penthouse roof, and main roof.  The existing roof type was ballasted EPDM, which was converted to EnergyStar Thermoplastic Polyolefin (TPO).  Replacements were made to the expansion joint, skylight, smoke hatch, and roof anchor. 
  • The 1801 McCormick Drive building had four roof levels on the second floor, fourth floor terrace, main roof, and upper penthouse roof.  The existing roof type was built-up hot mopped asphalt, which was converted to EnergyStar modified bitumen.  Replacements were made to the expansion joint, skylight, smoke hatch, roof anchor, steel catwalk bridge over MEP lines, and steel safety railing.
  • The 9301 Peppercorn Place building had a single flat roof consisting of built-up hot mopped asphalt, which was converted to EnergyStar modified bitumen.  Replacements were made to the expansion joint, skylight, smoke hatch, as well as the roof over the abandoned skylights. 
  • The 1441 McCormick Drive and 1221 Caraway Court buildings had a single flat roof consisting of ballasted EPDM, which was converted to EnergyStar TPO.  Replacements were also made to the expansion joint, skylight, smoke hatch, and the roof over the abandoned skylight.

3100 Clarendon Boulevard Building Modifications

Built in 1985-1986, the 14-story, 260,042 sf office building at 3100 Clarendon Boulevard, across from the Clarendon Metro plaza, underwent an extensive interior and exterior renovation in February 2014. SK&A’s Repair & Restoration Division provided repairs to the existing building’s main façade and various structural slabs, and designed the new monumental stairs.

The façade repairs consisted of the removal and replacement of the existing stone cladding on all four sides of the building with new aluminum glass cladding. SK&A provided deflection, load, and design criteria for the support system of the new cladding. Existing structural slabs were extended on the east side of the ground floor and second floor level. SK&A also designed new cutouts for two new elevators at the center and west sections of the building. In addition, a new steel dunnage was designed to install mechanical equipment on the third floor plaza and penthouse roof.

The lobby area renovations included a new second floor level and monumental stairs. The steel and glass stairs were a challenge to install due to the sharp angle of the stairs. One set of stairs connects the ground level to the Metro level and another set of stairs connects the ground level to the second floor level.

The project was awarded the Juror’s Citation in Commercial Interiors at the 2016 Design Awards presented by the AIA Northern Virginia Chapter.

600 Massachusetts Avenue, NW

Located adjacent to the Washington Convention Center and close to Chinatown, SK&A recently completed structural design services for this new 12-story, concrete-framed Class “A” commercial office building.  Currently under construction, the structure includes 401,000 gsf of above-grade space, plus an additional 44,000 gsf of space on a below-grade concourse.  Parking is provided on three below-grade levels and totals approximately 132,500 gsf.  The project also required the relocation and restoration of two historic townhouses as additional office space. 

The building’s exterior facade incorporates natural stone, brick, and metal paneling along the glass curtain wall system.  Perimeter columns are spaced 30 feet apart for maximum openness and space.  Additional features include a light-filled lobby with stone flooring, wood and stone walls, and a water feature; floor plates with slab-to-slab heights of at least 11 feet; private balconies on five floors; and a rooftop terrace with an outdoor conference area.