The revamped 426,000-sq-ft building on a confined downtown site at 9th and G streets features a redesigned entryway, auditorium and double-height reading room. It also includes music and art studios and a 19,000-sq-ft creative lab with welding and carpentry shops for trade students. Adjacent to a 13,500-sq-ft children’s area is a steel and concrete sloped deck topped by a wooden slide.

To create an open layout, the team removed the building’s original four cores, masonry walls and some unnecessary floor-to-ceiling stacks. Libraries have morphed from being “book-centric to something that’s more community-centered,” says Steven Jensen, principal for executive architect OTJ.

The project also required major concrete restoration. The year-long demolition period involved lead paint and asbestos abatement.

Substantial construction of the construction manager at-risk/guaranteed maximum price project was achieved on budget and one day early—in the midst of the COVID-19 crisis in April. “As if it wasn’t challenging enough already,” Jensen says.

In April, four workers tested positive for coronavirus, prompting the team to perform its own contact tracing and to increase the frequency of jobsite cleanings. Craftworkers also resequenced work to maintain social distancing. “We knew where crews were working and their paths,” says Peter Ege, project executive for the Smoot|Gilbane joint venture that is the project’s construction manager. Ege says the four workers are healthy and are working on new jobs.

Implemening COVID-19 health practices was made easier as the workforce at the site, 300 at its peak, had thinned down to 200 workers in March and 150 or fewer in April.

The team says crews continue to follow COVID-19 protocols as they work to complete punch-list items ahead of the library’s planned fall reopening. In addition, the team at press time was using money saved during earlier construction phases to build an operable glass wall, approximately 20 ft long, that opens to a large terrace on the new fifth floor, which creates about 38,000 sq ft of additional space.

Jensen hopes that working through the pandemic will let the library stick to its plan to open sometime this fall. James D. Fennelly, vice president of development for the library’s owner’s representative, Jair Lynch Real Estate Partners, says it’s unclear what COVID-19 measures will be in place when the library opens because “no one yet has a true handle on the new ‘normal.’” But he says the coronavirus is likely to affect the “public use of this awesome new facility.”

Redefining History

The original $18-million library opened in 1972 after four years of construction. The city’s only Mies van der Rohe building—and the only library Mies ever designed—was designated a historic landmark in 2007. Seven years later, library officials hired Martinez + Johnson Architecture and the Dutch firm Mecanoo Architecten to design the renovation. Martinez + Johnson has since merged with OTJ.

The design process included 60 community meetings and extensive regulatory review by city, state and federal agencies. Those reviews and meetings helped designers determine how to preserve the library’s “historic significance while implementing and planning for today and tomorrow’s infrastructure,” Jensen says. 

The redesign doesn’t “replicate Mies’ work” but offers a “contrast to identify what is Mies and what is new intervention,” Jensen adds. For example, curved elements, such as those on a pair of monumental helical staircases, run counter to the planes and grid that mark Mies’ design, Jensen says. 

Building the staircases, which corkscrew from the basement to the fifth floor, required demolishing and redesigning historic features but also preserving original floors. Fennelly says the stairs are a prime example of how the team protected a landmark building while satisfying the “need and desire to modernize and create open and modern interactive public amenities.”

Mechanical Systems

Engaging the CM when the schematic design was 20% complete proved critical to the project, the team says. For one thing, by using value engineering, the JV helped to correct a $20-million budget overrun. It also decided to front-load mechanical, electrical and plumbing work. That included installing permanent chillers before installing “high-end millwork that is very sensitive to temperature and humidity fluctuations,” Ege says. Special air conditioning is also needed for the library’s archives.

Close coordination with the mechanical contractor, R&R Mechanical, and the commissioning agent, Liberty Engineering, helped determine which chillers to install first. “We had to push some risers and ductwork earlier,” Ege says. 

Upgrading the main MEP plant wasn’t simple because it is located three levels below grade with no direct access. To place the MEP units, the team cut a 10-ft by 18-ft opening into the sidewalk near the loading dock.

It craned and rigged large mechanical units into place about 30 ft below grade, through a steel shaft punched through two existing slabs. Some units had to be broken into pieces and bolted back together inside the plant. A 259-in.-long by 175-in.-wide by 179-in.-tall outside air handling unit was broken down into five pieces. Two 13.2-kV transformers, each weighing 25,000 lb, were the heaviest units rigged through the sidewalk opening. After all of the units were placed, the team covered the sidewalk hole with three removable 3-ft-3-in. by 10-ft precast modular panels in case the units need to be removed for maintenance.

Another challenge involved resequencing the installation of the MEP infrastructure due to unforeseen site conditions. Those poor conditions included water damage in the north core where “there was a lot of required sequencing due to the massive size of ductwork and pipes and feeder pipes,” Ege says. Before making some MEP-steel connections, the team also had to demolish asbestos-laden concrete wrapped around steel beams that had been used for fireproofing.

While crews repaired or replaced damaged concrete, horizontal MEP installations on the library floor were resequenced ahead of vertical risers. Ege says steel and concrete work to support the MEP vertical infrastructure was done concurrently with horizontal MEP installations. “We worked with our trade partner to supplement the initial crews that were diverted to the other work and added new smaller crews focused solely on the delayed vertical installation,” says Ege, who notes that overtime also helped mitigate lost time and delays.

Crane Watch

For approximately two months, a 360-ton mobile hydraulic crane operated from G Street, about 15 ft above a Washington Metropolitan Area Transit Authority (WMATA) substation and active Metro Red Line tunnel. The team worked with the crane manufacturer and WMATA to maintain uninterrupted train service.

Ege says it took months to settle on a crane configuration that allowed the jib to reach the farthest cores without exceeding WMATA’s ground-surge requirements. That contributed to delays in steel erection, he says. Automatic sensors in the tunnel and adjacent vent shaft, plus periodic visual checks, provided real-time surge data.

One concern about the crane, however, was that the team couldn’t “weathervane” it because of its size and configuration. That became nerve-fraying because the crane was mobilized during the 2018 hurricane season. The team devised a contingency plan to take down the jib without blocking traffic.  But fortunately, hurricanes spared D.C. in that time period and the plan didn’t have to be activated.

 Ultimately, the crane lowered steel for the monumental staircases through separate 30-ft by 60-ft holes cut in the roof, which required rigging the staircases from the roof and blind picks. Additionally, the team craned steel for the fifth-floor. Risers for the 200-seat auditorium were craned through an even larger, 60-ft by 60-ft hole in the roof.

Windows, Pavers and Pipes

The building’s historic exterior of matte black steel, brick and bronzed-tinted glass had to be meticulously restored. Exterior steel doubled as glazing channels and needed to be “in very good shape before we put the glass in,” Ege says. Steel restoration involved multiple stages of blasting and priming before applying several coats of paint to match the original black.

Jensen says only three manufacturers in the world make the required 10-ft by 10-ft glass panes. The D.C. Historic Preservation Office approved windows made in Austria “to match the original Mies glazing color with low distortion,” Jensen says.

The team worked with the manufacturer to maximize the window’s thermal capabilities. Ege says that could help achieve the project’s targeted LEED Gold status. However, about 30 of the building’s 470 windows had to be replaced after installation because of a factory defect, according to Ege.

The team also cleaned and repaired the building’s original granite sidewalk pavers. Broken pavers were recast from stone sourced from the same quarry in Minnesota that the original project team used.

Some 830 pavers from the building’s perimeter were stored in the underground parking garage—the site’s only substantial laydown space. But about a year into construction, the team discovered that its access to the 5-ft by 5-ft pavers in the garage was limited by concrete restoration that occurred there that was more extensive than initially realized. A water-damaged concrete ramp was the only entryway to the laydown area; elevators had already been removed but not yet replaced. The ultimate solution to the access problem was installing a material hoist within an existing elevator shaft.

The team also discovered spalling on the garage’s topping slab, caused by a clogged, deteriorated drainage system formed in the existing structural slabs. As the team prepared to demolish the concrete recess and repour a new trough, a plumber suggested fitting a prefabricated drainpipe in the trench. Feeding the 4-in.-wide, 720-ft-long PVC pipe through existing concrete saved the team about $500,000 and two months of work, Ege recalls.  

He notes that the team postponed the concrete restoration in the garage as long as possible, to preserve the main laydown area. “Once the pavers started getting reset on the exterior last summer,” Ege says, “we started to block off sections of the garage to new storage and started the [concrete] removal and replacement process in quadrants.”

Lasting Legacy

The team recently reinstalled two murals depicting the life of Martin Luther King Jr. in the library’s ground-floor entrance. They had been stored off site during construction. To create an informal performance space in front of the murals, the project team pushed back the mural wall 4 ft and installed risers for people to sit on during performances. The team also restored the entrance’s original brick interior walls and reception desk while adding modern ceilings and light fixtures.

Ege says he often thinks about the thousands of people, especially children, “who will come through here after we’re done and will be inspired by this new modern library.” He adds, “It’s not just another project in D.C., it’s improving the heart of the city’s fabric.”