Before the foundations were built, the builders drilled several test boreholes to determine the composition of the underlying soil. Contracts for digging the foundation were awarded in August 1906 before the plans were approved. The plans for the Singer Tower were approved on September 12, 1906, and excavation began later that month, with work officially beginning on September 19. A timber platform, measuring wide and descending from Broadway to the excavation site, was constructed so that workers could receive materials and extract soil more efficiently. The first steel shipments for the anchorages arrived in October 1906. Foundation work was completed on February 18, 1907.