Headquarters of the United Nations their own rooms, the UN would be able to reduce its own expenditures. The headquarters were originally supposed to be completed in 1951, with the first occupants moving into the Secretariat Building in 1950. However, in November, New York City's construction coordinator Robert Moses reported that construction was two months behind schedule. By that time, 60% of the headquarters' site had been excavated. The same month, the United Nations General Assembly unanimously voted to formally thank the national, state, and city governments for their role in building the headquarters. The formal $23.8 million contract for the Secretariat Building was awarded
Headquarters of the United Nations the complex opened in 1950, were expected to take about 7 years to complete. When completed the complex is also expected to be more energy efficient and have improved security. A temporary $140 million "North Lawn Building" was built to house the United Nations' "critical operations" while renovations proceeded. Work began on May 5, 2008, but the project was delayed for a while. By 2009 the cost of the work had risen from $1.2 billion to $1.6 billion with some estimates saying it would take up to $3 billion. Officials hoped the renovated buildings would achieve a LEED Silver rating.