By January 1934, the Fed purchased the Montauk Building for less than $400,000, thereby acquiring a land lot of . This had been the only structure on the city block that the Fed had been unable to acquire when it started assembling land for the Federal Reserve Building fifteen years prior. York and Sawyer was hired to design the addition, while Marc Eidlitz & Son was hired as the main construction contractor. The Montauk Building's last tenants vacated the building in June 1934, and demolition of the Montauk Building started. By the next month, plans for the annex were filed with the Manhattan Department of Buildings. The executive offices of the annex were formally opened in December 1935, but some of the lower floors were occupied several weeks before that.