The original building soon became too small to accommodate the operations of Irving Trust and its tenants. Accordingly, in 1961, Irving Trust purchased from Hanover Bank the three buildings at 60, 62, and 70 Broadway, thereby giving Irving Trust control of the entire block between Broadway, Wall Street, New Street, and Exchange Place. The company initially anticipated that the annex would cost $25 million. Voorhees, Walker Smith Smith & Haines were hired to design the annex. By mid-1963, the site had been cleared; in preparation of the work, Irving Trust took a sublease at 2 Broadway. To finance construction, Irving Trust sold the building to a subsidiary, which then sold $30 million of secured notes to investors. Renovations also took place in the original building; tenants continued to use 1 Wall Street during construction, but the vault in the basement was emptied. A refrigeration plant was installed on the annex's roof to provide air-conditioning to both buildings. The project was finished by late 1965. 1987 and 1988, Irving Trust held negotiations to merge with the Bank of New York, which at the time was headquartered nearby at 48 Wall Street. Irving Trust initially rejected buy-out offers from the Bank of New York because the latter had "undervalued" Irving Trust's assets such as 1 Wall Street. By October 1988, with a merger imminent, Irving Trust placed 1 Wall Street for auction; at the time, the building was valued at $250 million. With the Bank of New York's acquisition of the Irving Trust in December 1988, the company became known as BNY Mellon, and its headquarters moved to 1 Wall Street.