Project Federal Building & U.S. Courthouse in Milwaukee
Architect Mills + Schnoering Architects
In Milwaukee, the Federal Building and U.S. Courthouse is a defining feature of the Wisconsin city’s downtown skyline.
Since 1899, when it was completed, the grand granite Romanesque Revival edifice with the monumental tower on the north end has formed a perfect complement to the iconic Pfister Hotel, which dates to 1893, and the Wisconsin City Club, which is housed in an 1895 mansion, and a counterpoint to the more modern monoliths that surround and sometimes soar far beyond its slate roof.
More than a century of time (and the Brew City’s brutal winters) took their toll on the building as did a 1964 cleaning effort using hydrofluoric acid that changed the chemical composition of the granite’s surface, creating a crust that gave the façade a blotchy appearance and accelerated exfoliation of the stone.
The General Services Administration, through its national Design Excellence Program competition, commissioned Mills + Schnoering Architects, which is based in Princeton, New Jersey, to clean and repair the facade and its carved ornamentation, which features allegorical figures, stylized flora, strapwork and heraldic details.
The mission of the team—Michael J. Mills, FAIA, lead designer and partner in charge; Anne E. Weber, FAIA, FAPT, project manager; and Christa J. Gaffigan, AIA, LEED AP, BD+C, project architect—was to carefully bring the façade back to its original splendor, using, Mills says, “the gentlest, most effective methods of preservation and restoration technology possible” to secure the courthouse for at least a half century.
Mills + Schnoering Architects’ partners in this effort were Deborah Slaton, Ken Itle and Mike Ford of Wiss Janney Elstner Associates.
The courthouse building, which covers a city block and nearly 55,000 square feet, includes a seven-story U-shaped addition made of Rockville Beige granite. The addition was completed in phases—in 1929-1932 and 1940—and forms an interior courtyard on the south end of the structure.
The main building, designed by architect Willoughby J. Edbrooke, features a one-story arched entrance loggia; symmetrical, gabled-roof center bays on the east and west elevations and a half dozen cylindrical towers on the corners that are topped by conical roofs.
Originally a U.S. post office, court and custom house, the building is made of smooth-dressed Mt. Waldo granite from Maine and has a rusticated base of Athelstane-Amberg granite.
The Mills + Schnoering team, which used a pair of articulated boom lifts and a rappelling crew to survey the massive structure, identified a number of distress conditions, including deterioration of the stone cornices at the corner turrets; vertical cracking in the 1940 addition; water penetration in the roof of the loggia; and widespread exfoliation of granite in the original building. Crews used a sounding hammer to find underlying, concealed issues in the granite.
“The building was in such bad shape that for several years the turrets had been covered in stainless steel net screening to prevent pieces of damaged stone from falling to the ground below and injuring people or property,” Mills says, adding that his team also disassembled, redesigned and reinstalled new gutters to halt water infiltration in the turrets. “It was very visible from the street—it looked like they were wearing Band-Aids.”
After evaluating several methods and running tests on on-site mockups, Mills and his team decided to clean the building with sponge jets, which involves spraying surfaces with a micro-abrasive medium embedded in the sponge.
The treatment, which Mills calls “effective and gentle,” not only removed dirt and loose exfoliated stone, but it also evened out the façade’s appearance.
“It’s eco-friendly,” he says. “The product can be recycled and reused.”
The previous cleaning, he notes, was so drastic that “newspapers at the time remarked on the acid’s strong smell and the fact that car finishes near the site were ruined; apparently, even the hosiery of passing women was damaged by the acid’s airborne mist.”
The project presented a number of significant challenges, including the unanticipated discovery and removal of hazardous materials in the basement.
Because the courthouse is on the National Register of Historic Places, the GSA had to consult with and coordinate the work with the Advisory Council on Historic Preservation, the State Historic Preservation Office and the Secretary of the Interior’s Standards of Historic Preservation.
The courthouse, which is on one of the city’s busiest streets, remained open during the two-year project, so the team had to work around its schedule, which meant seven-day weeks and night shifts.
“The sponge-jet cleaning, for instance, is jet-engine loud, so it had to be done overnight,” says Mills, who adds that the city’s short construction season made timing all the more complicated and the deadline all the more urgent.
Because space around the building was limited and congested, the crews set up a temporary material staging area a block from the site. To repair the south corners of the building, which required a lot of reconstruction, workers used swing stages for access and turned the roof into a stone yard.
The historic skylights were protected by air pillows that were craned over the building and positioned in place, and the slate roof, copper gutters and wood windows, all of which had recently been repaired or restored, also were covered to protect them during the masonry work.
Mills says that the new façade makes a dramatic difference. “When we were halfway done, we were able to remove the scaffolding on one side,” he says. “I stood across the street, and it was exciting to see what it was before next to what it is now.”
Mills, who is from Ohio, says he was thrilled to be chosen to do such a prestigious project in a Midwestern state. “What I regret the most is that the job is over,” he says.
Architect Mills + Schnoering Architects
Structural Engineer and Materials Conservator Wiss, Janney, Elstner Associates
General Services Administration Team Carly Thompson, Regina Nally, Chris Braun
General Contractor The Tradesmen Group
Building/Scaffold Structural Engineer and Surveyor GZA Engineers
Electrical and Lighting Subcontractor Walkowiak Electric
Asbestos and Lead Abatement Robinson Brothers Environmental
Stone Suppliers Coldspring Granite and Granites of America
Stone Fabricator Metro Stone
Brick Manufacturer Belden Brick
Brick Supplier County Materials Corp.
Roofing Manufacturer Kemper System
Scaffold Supplier Universal Manufacturing Corp.
Cost Estimator Becker & Frondorf
Lighting Design Emilio Bras Museum Services