Permanent representative to the United Nations rarely, a UN permanent ambassador, to distinguish the position from being a UNESCO goodwill ambassador. However, again, the term "ambassador" is more commonly used to describe each of nation's government officials who are assigned to handle some affairs with another nation. Permanent representative to the United Nations A permanent representative (sometimes called a "UN ambassador") is the head of a diplomatic mission to the United Nations. Of these, the most high-profile UN permanent representatives are those assigned to headquarters in New York City. However, member states also appoint permanent representatives to the other UN offices in Geneva, Vienna, and Nairobi.
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.