Celebrating America's Birthplace From William Penn to Rocky


From its beginnings as the centerpiece of American history, to its emergence as one of the largest metropolitan areas in the U.S., the city of Philadelphia has represented a rich mix of commercial and residential districts that intermingles a broad range of architectural styles. "At the core of the City's uniqueness is its architecture, which throughout history has reflected the cultural, political, and social issues of the times," according to AIA Philadelphia.

Echoing this view, the Philadelphia Inquirer observed, "The city boasts an architectural lineage longer and more varied than that of almost any other place in America, ranging from the Lilliputian colonial-era houses along Elfreth's Alley to the gargantuan, newly minted Comcast Center, the country's tallest green skyscraper."

At the heart of the city is its downtown area, known locally as Center City, where tall buildings such as Comcast Center, One Liberty Place, BYB Mellon Center and Three Logan Square mingle with well-defined neighborhoods and many of Philadelphia's 66 National Historic Landmarks.

Among Center City's distinctive neighborhood districts is Rittenhouse Square, which was designated as one of "North America's Top 12 Public Squares" by the Project for Public Spaces (PPS). "The space is among the best-used public spaces in the United States," the PPS stated in its profile of the district. "A variety of buildings, most of them architecturally notable, surround the park: elegant turn-of-the-century apartment buildings, brownstones, and the mansions that make up the Curtis Institute and Art Alliance, as well as modern high-rises."

Other neighborhoods and districts in Center City include Elfreth's Alley, which is the country's oldest residential neighborhood; the affluent Society Hill with its cobblestone streets and brick row houses; and Washington Square, home to the city's antique row and the country's oldest hospital, Pennsylvania Hospital.

Dissecting the northwest quadrant of Center City is the mile-long Benjamin Franklin Parkway designed in 1917 to imitate the Champs- Élysée in Paris. Along the Parkway lies the city's Art Museum District featuring the Academy of Natural Sciences, Rodin Museum, the Franklin Institute and Benjamin Franklin National Memorial, and the Philadelphia Museum of Art that was featured in the Oscar-winning film Rocky.

The Parkway intersects with Philadelphia City Hall, which the American Institute of Architects (AIA) designated as "the greatest single effort of the late 19th century American architecture." When the AIA asked architects and the general public to rank their favorite buildings, the City Hall was picked as the fourth-favorite government building behind the White House, the U.S. Capitol and the U.S. Supreme Court, freelance writer Sandy Smith reported in an article for City Mayors. "The building is graced with 250 works of sculpture, from great ones like the 37-foot-tall statue of (William) Penn atop its tower - the tallest sculpture on any building anywhere - to humorous flourishes like the cat-and-mouse motif found in the building's south portal," Smith noted.

A National Historic Landmark, Philadelphia City Hall was constructed in French Second Empire Architecture over a 30-year period, from 1871 to 1901. "Records indicate that 88,000,000 red bricks and 300,000 pressed or glazed bricks were used in the construction of the building.," STRUCTURES magazine revealed.

In 1998, a major renovation of the City Hall's exterior was initiated. "It was to include rehabilitation of exterior masonry, stone sculptures and carvings, ornamental cast iron, windows and air conditioners, roofing and flashings," STRUCTURES magazine stated. "Every piece of cast iron was thoroughly cleaned to sound metal with needle guns to remove old lead paint and rust. The residue was collected, put in metal drums, and treated as hazardous waste. Surfaces were immediately primed to prevent rust bloom. Sound pieces of cast iron could remain in place, renewing fasteners with stainless steel. Fasteners of ornamental pieces applied to enclosing plates were also replaced with stainless steel."

Minor repairs of cast iron were made on site using stainless steel reinforcement, although major repairs required metal to be removed, refurbished in the shop and reinstalled on the structure. "Badly damaged pieces were removed and used as a pattern for oversized models," STRUCTURES magazine reported. "New molds were then prepared and replacement pieces cast. Fit of the new pieces on the building was very good."

The protective coating system for the project was a prime coat of Series 530 Omnithane, a moisture-cured aromatic polyurethane, followed by an intermediate coat of Series 66 Hi-Build Epoxoline, a polyamide epoxy and a finish coat of Series 1075 Endura-Shield II, an aliphatic acrylic polyurethane. "We had to go through a pretty extensive process for the off-white color to be approved," recalled Tnemec coating consultant Pat Murphy who was involved with the project during its early stages. "This is the most recognizable historic building in Philadelphia, so maintaining its architectural significance was a paramount consideration."

"The City Hall project has spanned nearly a decade," Tnemec coating consultant Ed Enoch added. "Containment for the surface preparation and scaffolding was very expensive, so the owner wanted a coating system with long-lasting performance."

In 2009, the City Hall project received the prestigious Preservation Achievement Award from the Preservation Alliance of Greater Philadelphia. The project was selected by an independent jury of preservation experts from throughout the region and from many perspectives, according to an article in PlanPhilly.com.

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