The building was designed by Scottish-born architect
John McArthur Jr. (1823–1890), and
Thomas Ustick Walter (1804–1887). in the
French Second Empire style of architecture, and was constructed from 1871 to 1901 at a cost of $24 million (equivalent to $ million in ). The City Hall's tower was completed by 1894, although the interior was not finished until 1901. Designed to be the world's tallest building, it was surpassed during the phase of construction by the
Washington Monument (of Washington, D.C.), the
Eiffel Tower (in Paris, France), and the
Mole Antonelliana. The Mole Antonelliana was a few feet taller and was the tallest masonry (i.e. without the use of steel) building in the world until 1953. In that year a storm caused the spire to collapse and so the Philadelphia City Hall then became the tallest masonry building in the world (excluding monuments). Upon completion of its tower in 1894, it became the world's tallest habitable building. It was also the first secular building to have this distinction, as all previous world's tallest buildings were religious structures, including European cathedrals and—for the previous 3,800 years—the
Great Pyramid of Giza; even the Mole Antonelliana was supposed to be a religious building—a synagogue—but then received a different use. The location chosen was one of the five center city urban park squares dedicated by William Penn, that geometrically is the center to the other four squares within
Center City renamed as Penn Square. City Hall is a
masonry building whose weight is
borne by granite and brick walls up to thick. The principal exterior materials are
limestone,
granite, and
marble. The original design called for virtually no sculpture. The stonemason William Struthers and sculptor
Alexander Milne Calder were responsible for the more than 250 sculptures, capturing artists, educators, and engineers who embodied American ideals and contributed to this country's genius. The city spent a total of $24.6 million on the erection of the building between 1870 and 1904. At , including the statue of city founder
William Penn atop its tower, City Hall was the tallest
habitable building in the world from 1894 to 1908. It remained the tallest in Pennsylvania until it was surpassed in 1932 by the
Gulf Tower in
Pittsburgh; it is now the 16th tallest. It was the tallest in Philadelphia until 1986 when the construction of
One Liberty Place surpassed it, It was constructed over the time span from 1871 to 1901 and includes 700 rooms dedicated for uses of various governmental operations. The building structure used over 88 million bricks and thousands of tons of marble and granite. With almost 700 rooms, City Hall is the largest municipal building in the United States and one of the largest in the world. The building houses three branches of government: the city's executive branch (the
Mayor's Office), its legislature (the
Philadelphia City Council), and a substantial portion of the judicial activity in the city (the Civil Division and Orphan's Court of the
Pennsylvania Court of Common Pleas for the First Judicial District are housed there, as well as chambers for some criminal judges and some judges of the
Philadelphia Municipal Court). It was the
tallest clock tower in the world when it was completed; it was surpassed by the
Metropolitan Life Insurance Company Tower in 1912, and is currently the 5th tallest building of this type. The tower features a clock face on each side that is in diameter. The clock faces are larger in diameter than those on
Big Ben which measure . City Hall's clock was designed by Warren Johnson and built in 1898. The 1937
Philadelphia Guide noted that "shortly after the clock was installed the city inaugurated a custom which still continues. Every evening at three minutes of nine the tower lights are turned off, and then turned on again on the hour. This enables those within observation distance, though unable to see the hands, to set their timepieces. There are four bronze eagles, each weighing three tons with wingspans, perched above the tower's four clocks. Once enclosed with
chain-link fencing, the observation deck is now enclosed by glass. It is reached in a 6-person elevator whose glass panels allow visitors to see the interior of the iron
superstructure that caps the tower and supports the statuary and clocks. Stairs within the tower are only used for emergency exit. The ornamentation of the tower has been simplified; the huge garlands that festooned the top panels of the tower were removed. In the 1950s, the city council investigated tearing down City Hall for a new building elsewhere, but abandoned the plan due to the high cost of the demolition. Beginning in 1992, Philadelphia City Hall underwent a comprehensive exterior restoration, planned and supervised by the Historical Preservation Studio of Vitetta Architects & Engineers, headed by renowned historical preservation architect Hyman Myers. The majority of the restoration was completed by 2007, although some work has continued, including the installation of four new ornamental courtyard gates, based on an original architectural sketch, in December 2015. The building was voted 21st on the
American Institute of Architects' list of Americans' 150 favorite U.S. structures in 2007. ==William Penn statue==