Headquarters of the United Nations be sent by courier. The United Nations Postal Administration issues stamps, which must be used on stamped mail sent from the building. For award purposes, amateur radio operators consider the UN headquarters a separate "entity" under some award programs such as DXCC. For communications, UN organizations have their own internationally recognized ITU prefix, 4U. However, only contacts made with the UN Headquarters in New York, and the ITU count as separate entities. Other UN organizations such as the World Bank count for the state or country they are located in. The UN Staff Recreation Council operates amateur radio station 4U1UN,
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.