The structural steel was pre-ordered and pre-fabricated in anticipation of a revision to the city's building code that would have allowed the Empire State Building's structural steel to carry , up from , thus reducing the amount of steel needed for the building. Although the 18,000-psi regulation had been safely enacted in other cities, Mayor Jimmy Walker did not sign the new codes into law until March 26, 1930, just before construction was due to commence. The first steel framework was installed on April 1, 1930. From there, construction proceeded at a rapid pace; during one stretch of 10 working days, the builders erected fourteen floors. This was made possible through precise coordination of the building's planning, as well as the mass production of common materials such as windows and spandrels. On one occasion, when a supplier could not provide timely delivery of dark Hauteville marble, Starrett switched to using Rose Famosa marble from a German quarry that was purchased specifically to provide the project with sufficient marble.
The structural steel was pre-ordered and pre-fabricated in anticipation of a revision to the city's building code that would have allowed the Empire State Building's structural steel to carry , up from , thus reducing the amount of steel needed for the building. Although the 18,000-psi regulation had been safely enacted in other cities, Mayor Jimmy Walker did not sign the new codes into law until March 26, 1930, just before construction was due to commence. The first steel framework was installed on April 1, 1930. From there, construction proceeded at a rapid pace; during one stretch of 10 working days, the builders erected fourteen floors This was made possible through precise coordination of the building's planning, as well as the mass production of common materials such as windows and spandrels. On one occasion, when a supplier could not provide timely delivery of dark Hauteville marble, Starrett switched to using Rose Famosa marble from a German quarry that was purchased specifically to provide the project with sufficient marble.