United Nations System peace and security. Its powers, outlined in the United Nations Charter, include the establishment of peacekeeping operations, the establishment of international sanctions, and the authorization of military action. Its powers are exercised through United Nations Security Council resolutions. The Security Council held its first session on 17 January 1946 at Church House, Westminster, London. Since its first meeting, the Council, which exists in continuous session, has travelled widely, holding meetings in many cities, such as Paris and Addis Ababa, as well as at its current permanent home at the United Nations Headquarters in New York City. There are 15 members
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.