Norwegian Embassy Renovations

Originally constructed in 1977, the Chancery at The Royal Norwegian Embassy in Northwest Washington, DC was in need of modernization.  The design team was tasked with improving the function, accessibility, and sustainability of the space using architectural and structural elements that evoke Norway’s rich history of shipbuilding and woodworking, while showcasing Norway’s natural resources, including wood and copper.  

The renovation features a garden room meeting and event space, a light-filled social hub, and a new entry level.  The garden room addition is distinguished by elegant, exposed glulam moment frames with concealed connections, in a nod to the Norwegian ship building legacy.  The social hub transformed an existing first floor patio into an atrium with a circulating stair.  Reinforcing of existing trusses surrounding the social hub was minimized by supporting the skylight and stair from a new hollow structural sections (HSS) structure above the original roof framing, with posts down to the existing columns. 

SK&A also served as the Building Enclosure Consultant for project and provided comprehensive technical reviews of the building enclosure and the various air, water, thermal, and vapor control materials and components and systems during the schematic design, design development, and construction documents phases.  SK&A performed a hygrothermal analysis per ASHRAE Standard 160 of the proposed wall and roof assemblies during the design development phase using the WUFI® Plus 3.1 software program.   

Capitol Hill Montessori at Logan

SK&A provided structural engineering services for the modernization of the existing 50,734 sf facility and introduction of new 54,000 sf additions, which include new classrooms, gymnasium, and rooftop turf field to improve the school’s current operations.   

The superstructure for the new additions consists of structural steel framing with composite steel beams, open web joists and long-span roof construction.   Steel framed full story trusses support the elevated walkway bridge between the new and existing buildings on the west side of the existing school.   Indoor common spaces were created by enclosing existing courtyard spaces between existing buildings with new steel framed roofs, supported by the existing building bearing walls. 


555 12th Street, NW, 11th Floor Renovation

The 555 12th Street, NW office building was constructed in the early 1990s and occupies the full city block between 11th and 12th Streets, NW and E and F Streets, NW.  Currently known as “District Center,” the building is constructed of reinforced concrete with post-tensioned floor slabs and features a full-height atrium at its center.  The almost 200,000 square feet of commercial office space in District Center has undergone many renovations to suit new tenants.  The latest renovation at the 11th floor was more involved than most tenant-related projects.  

SK&A was tasked with increasing the floor plate by 2,300 square feet by filling in a portion of a double-height space between the 10th and 12th floor.  In order to limit the structural depth and maximize the possible spans, SK&A proposed a system of Vierendeel trusses spanning between existing building columns.  The trusses featured HSS chord and web members and stand a total of 10’-6 ¾” tall.  There are two trusses (Labeled T2) that span 35’-6” from a building column to the shear wall at an elevator core.  A third truss (Labeled T1) spans the 45’-0” between the other two.  

Ingleside at Rock Creek

SK&A provided structural engineering services for the addition of new buildings and the renovation of an existing facility at the 14-acre Ingleside Retirement Community Campus in Washington, DC.  Located adjacent to Rock Creek Park at 3050 Military Road, NW, the non-profit retirement community’s current site was originally established in 1960.  The new changes to the site consist of:  

  • A new independent living facility (120,000 sf) with 90 units, a new assisted living facility (50,000 sf) with 15 residences, and structured parking (60,000 gsf).  The two residential buildings will connect to each other as well as existing buildings at the site.
  • A new skilled nursing and memory support facility (100,000 gsf), plus structured parking below (44,000 gsf).
  • A new independent living commons, renovation of the existing commons, as well as overall sitework (15,000 gsf).  The new commons or “Center for Healthy Living” will contain multiple amenity spaces, including a salon/day spa, classrooms and art studios, cafe, yoga and aerobics studio, technology center, meditation room, and fitness center.  

The Foundry, 200 Stovall Street

Built in the 1970’s, 200 Stovall was your typical 13-story, cast-in-place, conventionally reinforced, office building with a bland metal panel exterior skin and an interior forest of columns spaced 20’-0” on center.  Succumbed by the lackluster office market, the building was converted into a high-class residential tower (810,000 sf), fitting 525 residential units and 236 parking spaces with minimal demolition, foundation work, or column removal.

Using structural steel, an additional four floors were added to the existing concrete-framed building.  The vertical addition increased the lateral load on the existing concrete moment framed structure.  Vertical concrete shear walls and steel moment framed were post-installed at the lower floors to resist these additional lateral loads.  New openings in the second, third, and fourth floors were required for a new parking ramp.  To reduce weight, structural steel was used for the framing of these elements.  To modernize the exterior, the existing office-style metal panel façade was removed and replaced with a precast concrete panelized system with thin-set brick. 

Wardman Tower

Originally built in 1928, the historic Wardman Tower Hotel is a Georgian Revivalstyle building located on 2.5 acres of gardens in the Woodley Park neighborhood of Washington, DC. The hotel was renovated into 32 luxury condominiums featuring two-to four-bedroom homes ranging from 2,200-4,600 sf with luxurious finishes like wide oak panel flooring, automated window shades, and heated mosaic-tile bathroom floors. 

SK&A provided structural engineering services through three phases of design and construction for the Wardman Tower.  Phase one involved the underpinning and lowering of the basement level columns up to two feet, in order to obtain a 10-foot ceiling space.  Phase two consisted of underpinning one-third of the southeast wing and shoring the existing building two additional levels below grade, to provide a direct connection with a new two-story, below-grade cast-in-place parking garage.  Phase three involved the interior retrofit of the eight levels of hotel space into condominiums.  

SK&A also provided non-destructive examination (NDE) of the in situ reinforced concrete beams at the Wardman Tower luxury residential building.  The building’s superstructure is undocumented, and testing was done to determine the structural capacity of the existing structural system.  There were several cracks on the third and fourth floor concrete beams observed during a site walk-through.  SK&A provided NDE technicians to conduct ground penetration radar (GPR) scanning and perform impact echo tests (IE) at seven concrete beams to determine the existence of and locate, internal voids, micro-fissures, or delamination.  

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.

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. 

200 Eye Street, SE

Built in 1957, this former printing facility was a five-story building that included a basement level over pile foundations.  In the early 2000’s, the building was renovated to house a telecommunications firm, which was never occupied.  Floors were filled in on all levels and structural column modifications existed on some floors.

Completed in 2012, the building was converted to office space for occupation by various DC Government agencies.  The lowest level was converted to parking and a new two-level parking garage was constructed adjacent to the existing building on the east side.  Lateral stiffness of the building was enhanced using steel braced frames installed before removing the existing precast façade.  New elevator shafts and interconnecting stairs were framed at existing floor plates. Structural services also included the evaluation of existing structural elements for new loading, green roof evaluation and local strengthening.

The project has received the highest level of LEED certification–Platinum, as well as numerous awards of recognition.

733 15th Street, NW (The Woodward Building)

Complete restoration and conversion of a circa 1910 steel and concrete-framed 11-story office building (including one basement level) into a residential apartment building.  Historic restoration activities included modifying floors constructed of terra cotta flat arches with concrete fill, and rehabilitation of the multi-wythe brick façade.  The façade materials also included stone at the lower levels and terra cotta at the uppermost levels.  Several columns were removed in the basement to facilitate parking.  Hydraulic jacks were used to pre-deflect six new steel transfer girders at the ground floor used to replace the columns.  Stairs were reconfigured throughout, terraces added to the roof, and two vehicular elevators added to access the below-grade parking.

The project was awarded the 2009 Outstanding Project Award for Excellence in Structural Engineering by the Structural Engineers Association of Metropolitan Washington.